@article{shukla_an_chakrabortty_duel-hallen_2022, title={A Robust Stackelberg Game for Cyber-Security Investment in Networked Control Systems}, volume={9}, ISSN={["1558-0865"]}, url={https://doi.org/10.1109/TCST.2022.3207671}, DOI={10.1109/TCST.2022.3207671}, abstractNote={We present a resource-planning game for cyber-security of networked control systems (NCSs). The NCS is assumed to be operating in closed loop using a linear state feedback $\mathcal {H}_{2}$ -controller. A zero-sum, two-player Stackelberg game (SG) is developed between an attacker and a defender for this NCS. The attacker aims to disable communication of selected nodes and thereby render the feedback gain matrix to be sparse, leading to degradation of closed-loop performance, while the defender aims to prevent this loss by investing in the protection of targeted nodes. Both the players trade their $\mathcal {H}_{2}$ -performance objectives for the costs of their actions. The standard backward induction (BI) method is modified to determine a cost-based Stackelberg equilibrium (CBSE) that saves the players’ costs without degrading the control performance. We analyze the dependence of a CBSE on the relative budgets of the players and on the node “importance” order. Moreover, a robust defense (RD) method is developed for the realistic case when the defender is not informed about the attacker’s resources. The proposed algorithms are validated using examples from wide-area control of electric power systems. It is demonstrated that reliable and RD is feasible unless the defender’s resources are severely limited relative to the attacker’s resources. We also show that the proposed methods are robust to time-varying model uncertainties and thus are suitable for long-term security investment in realistic NCSs. Finally, we use computationally efficient genetic algorithms (GAs) to compute the optimal strategies of the attacker and the defender in realistic large power systems.}, journal={IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY}, author={Shukla, Pratishtha and An, Lu and Chakrabortty, Aranya and Duel-Hallen, Alexandra}, year={2022}, month={Sep} }
 @article{lian_chakrabortty_duel-hallen_2023, title={Game-Theoretic Mixed H<sub>2</sub>/H<sub>∞</sub> Control with Sparsity Constraint for Multi-Agent Control Systems}, ISSN={["2576-2370"]}, DOI={10.1109/CDC49753.2023.10384040}, abstractNote={A mixed $H_{2}/H_{\infty}$ control problem under a sparsity constraint is investigated for multi-agent control systems (MAS) to provide robustness against model uncertainty and to reduce the communication cost. First, proximal alternating linearized minimization (PALM) is employed to develop a centralized social optimization algorithm, which is guaranteed to converge to a globally optimal sparse controller. Next, we investigate a noncooperative game that accommodates different control performance criteria of the agents and propose a best-response dynamics algorithm based on PALM. A special case of this game produces a partially distributed social optimization solution. We validate the proposed algorithms using a network with open-loop-unstable nodes and demonstrate superiority of the PALM-based method to a previously investigated sparsity-constrained mixed $H_{2}/H_{\infty}$ controller.}, journal={2023 62ND IEEE CONFERENCE ON DECISION AND CONTROL, CDC}, author={Lian, Feier and Chakrabortty, Aranya and Duel-Hallen, Alexandra}, year={2023}, pages={5526–5531} }
 @article{an_shukla_chakrabortty_duel-hallen_2023, title={Robust and Scalable Game-theoretic Security Investment Methods for Voltage Stability of Power Systems}, ISSN={["2576-2370"]}, DOI={10.1109/CDC49753.2023.10383722}, abstractNote={We develop investment approaches to secure electric power systems against load attacks where a malicious intruder (the attacker) covertly changes reactive power setpoints of loads to push the grid towards voltage instability while the system operator (the defender) employs reactive power compensation (RPC) to prevent instability. Extending our previously reported Stackelberg game formulation for this problem, we develop a robust-defense sequential algorithm and a novel genetic algorithm that provides scalability to large-scale power system models. The proposed methods are validated using IEEE prototype power system models with time-varying load uncertainties, demonstrating that reliable and robust defense is feasible unless the operator's RPC investment resources are severely limited relative to the attacker's resources.}, journal={2023 62ND IEEE CONFERENCE ON DECISION AND CONTROL, CDC}, author={An, Lu and Shukla, Pratishtha and Chakrabortty, Aranya and Duel-Hallen, Alexandra}, year={2023}, pages={7061–7066} }
 @article{fallah dizche_duel-hallen_hallen_2022, title={Early Warning of mmWave Signal Blockage Using Diffraction Properties and Machine Learning}, volume={26}, ISSN={["1558-2558"]}, url={http://dx.doi.org/10.1109/lcomm.2022.3204636}, DOI={10.1109/LCOMM.2022.3204636}, abstractNote={Sensitivity to blockage challenges performance of millimeter-wave (mmWave) communication systems. We apply the MiniRocket machine learning (ML) method to provide reliable early warning of mobile mmWave signal blockage hundreds of milliseconds ahead, thus facilitates a proactive response. MmWave signal datasets for training and testing the ML method are created using our low-complexity physics-based simulation tool, which models diffraction accurately. Our insights and numerical results illustrate that the proposed early warning method is facilitated by the diffraction-induced pre-blockage signal patterns and is robust to diverse environmental and mobility conditions.}, number={12}, journal={IEEE COMMUNICATIONS LETTERS}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Fallah Dizche, Amirhassan and Duel-Hallen, Alexandra and Hallen, Hans}, year={2022}, month={Dec}, pages={2944–2948} }
 @article{an_chakrabortty_duel-hallen_2020, title={A Stackelberg Security Investment Game for Voltage Stability of Power Systems}, url={http://dx.doi.org/10.1109/cdc42340.2020.9304301}, DOI={10.1109/cdc42340.2020.9304301}, abstractNote={We formulate a Stackelberg game between an attacker and a defender of a power system. The attacker attempts to alter the load setpoints of the power system covertly and intelligently, so that the voltage stability margin of the grid is reduced, driving the entire system towards a voltage collapse. The defender, or the system operator, aims to compensate for this reduction by retuning the reactive power injection to the grid by switching on control devices, such as a bank of shunt capacitors. A modified Backward Induction method is proposed to find a cost-based Stackelberg equilibrium (CBSE) of the game, which saves the players’ costs while providing the optimal allocation of both players’ investment resources under budget and covertness constraints. We analyze the proposed game extensively for the IEEE 9-bus power system model and present an example of its performance for the IEEE 39-bus power system model. It is demonstrated that the defender is able to maintain system stability unless its security budget is much lower than the attacker’s budget.}, journal={2020 59th IEEE Conference on Decision and Control (CDC)}, publisher={IEEE}, author={An, Lu and Chakrabortty, Aranya and Duel-Hallen, Alexandra}, year={2020}, pages={3359–3364,} }
 @article{ali_duel-hallen_hallen_2020, title={Early Warning of mmWave Signal Blockage and AoA Transition Using sub-6 GHz Observations}, volume={24}, ISSN={["1558-2558"]}, DOI={10.1109/LCOMM.2019.2952602}, abstractNote={The susceptibility of millimeter-wave (mmWave) signals to physical blockage and abrupt signal strength variations presents a challenge to reliable 5G communication. This work proposes and examines the feasibility of utilizing lower-frequency signals as early-warning indicators of mobile mmWave signal blockage or recovery. A physics-based channel simulation tool incorporating Fresnel diffraction and image sources is employed to demonstrate that sub-6 GHz signals “lead” mmWave signals in reaching a specific signal-strength threshold by several to tens of milliseconds at mobile speeds, suggesting early-warning systems are viable. This predictive approach stems from frequency-dependent properties of diffraction and does not assume a specific topology or mobile and obstacle speeds. Realistic simulations that include transitions from line of sight (LoS) to non-line of sight (NLoS) and reflection scenarios are employed to verify the proposed prediction capabilities. Moreover, prediction of the strongest multipath component and its angle of arrival (AoA) using sub-6 GHz observations is investigated.}, number={1}, journal={IEEE COMMUNICATIONS LETTERS}, author={Ali, Ziad and Duel-Hallen, Alexandra and Hallen, Hans}, year={2020}, month={Jan}, pages={207–211} }
 @inproceedings{shukla_chakrabortty_duel-hallen_2019, title={A Cyber-Security Investment Game for Networked Control Systems}, url={http://dx.doi.org/10.23919/acc.2019.8815018}, DOI={10.23919/acc.2019.8815018}, abstractNote={We formulate a resource-planning game between an attacker and a defender of a Network Control System (NCS). We consider the network to be operating in closed-loop with a linear quadratic regulator (LQR). We construct a general-sum, two-player, mixed strategy (MS) game, where the attacker attempts to destroy communication equipment of some nodes, and thereby render the LQR feedback gain matrix to be sparse, leading to degradation of closed-loop performance. The defender, on the other hand, aims to prevent this loss. Both players trade their control performance objectives for the cost of their actions. A Mixed Strategy Nash Equilibrium (MSNE) of the game represents the allocation of the players' respective resources for attacking or protecting the important network nodes. Numerical results for the New England power system model demonstrate that reliable defense is feasible unless the cost of attack is much smaller than the cost of protection per generator.}, booktitle={2019 American Control Conference (ACC)}, author={Shukla, P. and Chakrabortty, A. and Duel-Hallen, A.}, year={2019}, month={Jul}, pages={2297–2302,} }
 @article{an_duan_chow_duel-hallen_2019, title={A Distributed and Resilient Bargaining Game for Weather-Predictive Microgrid Energy Cooperation}, volume={15}, ISSN={["1941-0050"]}, url={https://doi.org/10.1109/TII.2019.2907380}, DOI={10.1109/TII.2019.2907380}, abstractNote={A bargaining game is investigated for cooperative energy management in microgrids. This game incorporates a fully distributed and realistic cooperative power scheduling algorithm [cooperative and distributed energy scheduling (CoDES)] as well as a distributed Nash bargaining solution based method of allocating the overall power bill resulting from CoDES. A novel weather-based stochastic renewable generation (RG) prediction method is incorporated in the power scheduling. We demonstrate the proposed game using a four-user grid-connected microgrid model with diverse user demands, storage, and RG profiles and examine the effect of weather prediction on day-ahead power scheduling and cost/profit allocation. Finally, the impact of users’ ambivalence about cooperation and /or dishonesty on the bargaining outcome is investigated, and it is shown that the proposed game is resilient to malicious users’ attempts to avoid payment of their fair share of the overall bill.}, number={8}, journal={IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={An, Lu and Duan, Jie and Chow, Mo-Yuen and Duel-Hallen, Alexandra}, year={2019}, month={Aug}, pages={4721–4730} }
 @inproceedings{dizche_chakrabortty_duel-hallen_2019, place={Philadelphia, PA, USA}, title={Sparse Wide-Area Control of Power Systems using Data-driven Reinforcement Learning}, url={http://dx.doi.org/10.23919/acc.2019.8814445}, DOI={10.23919/acc.2019.8814445}, abstractNote={In this paper we present an online wide-area oscillation damping control (WAC) design for uncertain models of power systems using ideas from reinforcement learning. We assume that the exact small-signal model of the power system at the onset of a contingency is not known to the operator and use the nominal model and online measurements of the generator states and control inputs to rapidly converge to a state-feedback controller that minimizes a given quadratic energy cost. However, unlike conventional linear quadratic regulators (LQR), we intend our controller to be sparse, so its implementation reduces the communication costs. We, therefore, employ the gradient support pursuit (GraSP) optimization algorithm to impose sparsity constraints on the control gain matrix during learning. The sparse controller is then implemented using distributed communication. The proposed method is validated using the IEEE 39-bus power system model with 1149 unknown parameters.}, booktitle={2019 American Control Conference (ACC)}, author={Dizche, A.F. and Chakrabortty, A. and Duel-Hallen, A.}, year={2019}, month={Jul}, pages={2867–2872} }
 @article{lu_duel-hallen_2018, title={A Sensing Contribution-Based Two-Layer Game for Channel Selection and Spectrum Access in Cognitive Radio Ad-hoc Networks}, volume={17}, ISSN={["1558-2248"]}, url={http://dx.doi.org/10.1109/twc.2018.2810869}, DOI={10.1109/twc.2018.2810869}, abstractNote={In cognitive radio (CR) networks, the secondary users (SUs) sense the spectrum licensed to the primary users (PUs) to identify and possibly transmit over temporarily unoccupied channels. Cooperative sensing was proposed to improve the sensing accuracy, but in heterogeneous scenarios, SUs do not contribute equally to the cooperative sensing result because they experience different received PU signal quality at their sensors. In this paper, a two-layer cooperative game is developed for distributed sensing and access in multichannel CR ad hoc networks, where the SUs’ transmission opportunities are commensurate with their sensing contributions, thus fostering cooperation and eliminating free-riders. Numerical results show that the proposed two-layer game is computationally efficient and outperforms previously investigated collaborative sensing and spectrum access approaches in heterogeneous multichannel CR scenarios in terms of energy efficiency, throughput, SU fairness, and complexity. Moreover, it is demonstrated that this game is robust to changes in the network topology and the number of SUs. Finally, a new physical-layer approach is proposed to distribute the network-level miss-detection constraints fairly among the interfering SUs for guaranteed PU protection and demonstrate the performance advantages of the AND-rule combining of spectrum sensing results for heterogeneous SUs.}, number={6}, journal={IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS}, author={Lu, Yuan and Duel-Hallen, Alexandra}, year={2018}, month={Jun}, pages={3631–3640} }
 @inproceedings{lian_chakrabortty_wu_duel-hallen_2018, title={Sparsity-Constrained Mixed H 2 /H ∞ Control}, ISBN={9781538654286}, url={http://dx.doi.org/10.23919/acc.2018.8431378}, DOI={10.23919/acc.2018.8431378}, abstractNote={We propose an algorithm for designing sparsity-constrained controllers for linear time-invariant systems with model uncertainties using a mixed $H_{2}/H_{\infty}$ objective. We first improve a previously proposed descent algorithm for mixed $H_{2}/H_{\infty}$ control using a modified Zoutendijk's method. Thereafter, we impose a sparsity constraint on this design by combining it with a greedy gradient support pursuit (GraSP) method. The proposed algorithm guarantees a predetermined level of sparsity while maintaining acceptable $H_{2}$ performance as well as $H_{\infty}$ robustness to uncertainties in the open-loop model. The effectiveness of the proposed method is illustrated through simulations.}, booktitle={Proceedings of the Annual American Control Conference (ACC)}, publisher={IEEE}, author={Lian, Feier and Chakrabortty, Aranya and Wu, Fen and Duel-Hallen, Alexandra}, year={2018}, month={Jun}, pages={6253–6258,} }
 @inproceedings{an_duan_zhang_chow_duel-hallen_2017, title={Distributed multi-step power scheduling and cost allocation for cooperative microgrids}, url={http://dx.doi.org/10.1109/pesgm.2017.8273909}, DOI={10.1109/pesgm.2017.8273909}, abstractNote={Microgrids are self-sufficient small-scale power grid systems that can employ renewable generation sources and energy storage devices and can connect to the main grid or operate in a stand-alone mode. Most research on energy-storage management in microgrids does not take into account the dynamic nature of the problem and the need for fully-distributed, multi-step scheduling. First, we address these requirements by extending our previously proposed multi-step cooperative distributed energy scheduling (CoDES) algorithm to include both purchasing power from and selling the generated power to the main grid. Second, we model the microgrid as a multi-agent system where the agents (e.g. households) act as players in a cooperative game and employ a distributed algorithm based on the Nash Bargaining Solution (NBS) to fairly allocate the costs of cooperative power management (computed using CoDES) among themselves. The dependency of the day-ahead power schedule and the costs on system parameters, e.g., the price schedule and the user activity level (measured by whether it owns storage and renewable generation devices), is analyzed for a three-agent microgrid example.}, booktitle={2017 IEEE Power & Energy Society General Meeting}, publisher={IEEE Power & Energy Society General Meeting}, author={An, Lu and Duan, J. and Zhang, Y. and Chow, M. Y. and Duel-Hallen, Alexandra}, year={2017}, month={Jul}, pages={1–5} }
 @article{lian_chakrabortty_duel-hallen_2017, place={USA}, title={Game-Theoretic Multi-Agent Control and Network Cost Allocation Under Communication Constraints}, volume={35}, ISSN={["1558-0008"]}, DOI={10.1109/jsac.2017.2659338}, abstractNote={Multi-agent networked linear dynamic systems have attracted the attention of researchers in power systems, intelligent transportation, and industrial automation. The agents might cooperatively optimize a global performance objective, resulting in social optimization, or try to satisfy their own selfish objectives using a noncooperative differential game. However, in these solutions, large volumes of data must be sent from system states to possibly distant control inputs, thus resulting in high cost of the underlying communication network. To enable economically viable communication, a game-theoretic framework is proposed under the communication cost, or sparsity, constraint, given by the number of communicating state/control input pairs. As this constraint tightens, the system transitions from dense to sparse communication, providing the tradeoff between dynamic system performance and information exchange. Moreover, using the proposed sparsity-constrained distributed social optimization and noncooperative game algorithms, we develop a method to allocate the costs of the communication infrastructure fairly and according to the agents’ diverse needs for feedback and cooperation. Numerical results illustrate utilization of the proposed algorithms to enable and ensure economic fairness of wide-area control among power companies.}, number={2}, journal={IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS}, author={Lian, Feier and Chakrabortty, Aranya and Duel-Hallen, Alexandra}, year={2017}, month={Feb}, pages={330–340} }
 @article{lu_duel-hallen_2016, place={USA}, title={Channel-Aware Spectrum Sensing and Access for Mobile Cognitive Radio Ad Hoc Networks}, volume={65}, ISSN={["1939-9359"]}, url={http://dx.doi.org/10.1109/TVT.2015.2421913}, DOI={10.1109/tvt.2015.2421913}, abstractNote={In hardware-constrained cognitive radio (CR) ad hoc networks, secondary users (SUs) with limited sensing capabilities strive to discover and share available spectrum resources without impairing primary-user (PU) transmission. Sensing strategy design objectives include high CR network throughput, resolved SU competition, distributed implementation, and reliable performance under node mobility. However, these objectives have not been realized by previously investigated sensing strategies. A novel sensing strategy is analyzed, where the reward is adapted to the SU-link channel state information (CSI) prior to sensing, thus randomizing sensing decisions and boosting the network throughput. Moreover, CSI-aided sensing is combined with a novel first-come-first-served (FCFS) medium access control (MAC) scheme that resolves SU competition prior to sensing. Finally, a pilot-based CSI prediction method is developed to enable the proposed CSI-aided sensing strategies for mobile scenarios. Analytical and numerical results demonstrate that the proposed sensing and access methods significantly outperform nonadaptive sensing strategies for practical mobile CR scenarios with CSI mismatch and pilot overhead.}, number={4}, journal={IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY}, author={Lu, Yuan and Duel-Hallen, Alexandra}, year={2016}, month={Apr}, pages={2471–2480} }
 @article{an_duan_zhang_chow_duel-hallen_2016, place={USA}, title={Distributed Multi-Step Power Scheduling and Cost Allocation for Cooperative Microgrids [arXiv]}, volume={11}, journal={arXiv (USA)}, author={An, Lu and Duan, Jie and Zhang, Yuan and Chow, Mo-Yuen and Duel-Hallen, A.}, year={2016}, month={Nov}, pages={5 pp. -} }
 @article{lian_duel-hallen_chakrabortty_2016, title={Ensuring economic fairness in wide-area control for power systems via game theory}, DOI={10.1109/acc.2016.7525415}, abstractNote={Wide-area control helps in suppression of interarea oscillations in electric power systems, but potentially requires a substantial investment into the communication network needed to exchange state information. To provide companies with incentives to subsidize the wide-area communication links, a fair cost-allocation method based on the theory of cooperative network-formation games (NFG) is developed. The Nash Bargaining Solution (NBS) is utilized to fairly allocate the communication cost to the companies, which act as game-players. First, the wide-area control problem is formulated using the state-feedback-based LQR minimization approach, and the social communication cost is computed using a sparsity-promoting algorithm. Second, the disagreement point, which determines the maximum cost each area is willing to pay, is computed. This selfish cost is proportional to the energy an area saves by utilizing wide-area feedback and is derived from the Nash Equilibria (NEs) of two noncooperative NFGs, with and without wide-area feedback, respectively. Finally, the social cost is divided optimally among the companies, with all players benefiting from cooperation. The proposed cost allocation is illustrated for the Australian 50-bus power system example.}, journal={2016 American Control Conference (ACC)}, author={Lian, F. and Duel-Hallen, Alexandra and Chakrabortty, Aranya}, year={2016}, pages={3231–6} }
 @article{lu_duel-hallen_2016, place={USA}, title={Game-theoretic framework for cooperative sensing and fair spectrum access in multichannel cognitive radio networks [arXiv]}, volume={5}, journal={arXiv (USA)}, author={Lu, Yuan and Duel-Hallen, A.}, year={2016}, month={May}, pages={9 pp. -} }
 @article{lian_duel-hallen_chakrabortty_2016, place={USA}, title={Sparsity-constrained games and distributed optimization with applications to wide-area control of power systems [arXiv]}, volume={5}, journal={arXiv (USA)}, author={Lian, F. and Duel-Hallen, A. and Chakrabortty, A.}, year={2016}, month={May}, pages={9 pp. -} }
 @inproceedings{fairness.}_{yuan lu and duel-hallen, a.}_copyright=_2015, title={A two-layer coalitional game among rational cognitive radio users}, url={http://dx.doi.org/10.1109/CISS.2015.7086824}, DOI={10.1109/ciss.2015.7086824}, abstractNote={In cognitive radio (CR) networks, secondary users (SUs) sense the spectrum to identify and possibly transmit over temporarily unoccupied channels that are licensed to primary users (PUs). However, when the received PU signal is weak, spectrum sensing by individual SUs becomes unreliable. To improve sensing accuracy, SUs can form disjoint coalitions and cooperate to discover idle time slots. These spectrum opportunities are then shared among the coalition members in a coordinated manner. It is proposed to decouple the coalition formation and the access (payoff) allocation problems by modeling these processes as a two-layer coalitional game. This game fosters cooperation by providing each SU with the access opportunities it deserves. Numerical results demonstrate that the proposed game outperforms previously investigated collaborative sensing and access approaches in terms of energy efficiency, throughput, and fairness.}, note={Keywords= {cognitive radio;energy conservation;game theory;radio spectrum management;signal detection;wireless channels;two-layer coalitional game;rational cognitive radio users;CR networks;secondary users;spectrum sensing accuracy improvement;primary users;received PU signal;individual SU;disjoint coalition member;idle time slots;coalition formation;access allocation problems;collaborative sensing;access approach;energy efficiency;temporarily unoccupied channels;}, Pages= {6}, booktitle={2015 49th Annual Conference on Information Sciences and Systems (CISS). Proceedings}, author={fairness.}, Address= {Piscataway, N.J., U.S.A.} and {Yuan Lu and Duel-Hallen, A.}, Author= and Copyright=}, year={2015}, pages={– ,} }
 @inproceedings{lian_duel-hallen_chakrabortty_2014, place={Piscataway, NJ, USA}, title={Cost allocation strategies for wide-area control of power systems using Nash Bargaining Solution}, ISBN={9781467360906 9781479977468 9781479977451}, url={http://dx.doi.org/10.1109/cdc.2014.7039644}, DOI={10.1109/CDC.2014.7039644}, abstractNote={In this paper we present a novel game-theoretic strategy that guarantees fair cost allocation incurred by communication links in wide-area control for electric power systems. The underlying transmission network topology results in vastly diverse requirements for inter-area feedback for operating areas owned by different utility companies. Thus, it is unfair to divide the total communication cost equally among all companies. Our objective is to quantify these requirements and incorporate them into a fair cost distribution scheme. We formulate the wide-area control problem as a state-feedback based LQR minimization problem and cast it as a cooperative game with companies acting as game-players. We first apply sparsity-promoting optimization algorithms to construct the feedback gain matrix such that its off-diagonal blocks that characterize the inter-area feedback are as sparse as possible under a desired energy constraint. Assigning a fixed cost to every non-zero element in these off-diagonal blocks, we apply the Nash Bargaining Solution (NBS) to fairly allocate the total cost among the various game-players. Resulting insights into the wide-area communication requirements for different areas over a range of energy constraints are discussed.}, booktitle={53rd IEEE Conference on Decision and Control}, publisher={IEEE}, author={Lian, Feier and Duel-Hallen, Alexandra and Chakrabortty, Aranya}, year={2014}, month={Dec}, pages={1701–6} }
 @inproceedings{lu_duel-hallen_2013, place={Piscataway, NJ, USA}, title={Channel-Adaptive Spectrum Detection and Sensing Strategy for Cognitive Radio Ad-Hoc Networks}, url={http://dx.doi.org/10.1109/Allerton.2013.6736692}, DOI={10.1109/Allerton.2013.6736692}, abstractNote={In Cognitive Radio (CR) networks, multiple secondary network users (SUs) attempt to communicate over wide potential spectrum without causing significant interference to the Primary Users (PUs). A spectrum sensing algorithm is a critical component of any sensing strategy. Performance of conventional spectrum detection methods is severely limited when the average SNR of the fading channel between the PU transmitter and the SU sensor is low. Advanced detection techniques only partially remedy this problem. Cooperative sensing can combat channel fading, but requires a large number of cooperating SUs and/or diversity branches. A key limitation of conventional approaches is that the sensing threshold is determined from the miss detection rate averaged over the fading distribution. In this paper, the threshold is adapted to the instantaneous PU-to-SU Channel State Information (CSI) under the prescribed collision probability constraint, and a novel sensing strategy design is proposed for an overlay CR ad hoc network where the instantaneous false alarm probability is incorporated into the belief update and the reward computation. It is demonstrated that the proposed sensing approach improves SU confidence, randomizes sensing decisions, and significantly improves SU network throughput while satisfying the collision probability constraint to the PUs in the low average PU-to-SU SNR region. Moreover, the proposed adaptive sensing strategy is robust to mismatched and correlated fading CSI. In addition, threshold adaptation at a single SU sensor outperforms conventional cooperative sensing unless the number of cooperating SUs is very large. Finally, joint adaptation to PU channel gain and SU link CSI is proposed to further improve CR throughput and reduce SU collisions.}, booktitle={2013 51st Annual Allerton Conference on Communication, Control, and Computing (Allerton)}, author={Lu, Yuan and Duel-Hallen, A.}, year={2013}, pages={1408–14} }
 @inproceedings{lu_duel-hallen_2013, place={Piscataway, NJ, USA}, title={Channel-adaptive sensing strategy for Cognitive Radio ad hoc networks}, url={http://dx.doi.org/10.1109/CCNC.2013.6488485}, DOI={10.1109/ccnc.2013.6488485}, abstractNote={In Cognitive Radio (CR) ad hoc networks, secondary users (SU) attempt to utilize valuable spectral resources without causing significant interference to licensed primary users (PU). While there is a large body of research on spectrum opportunity detection, exploitation, and adaptive transmission in CR, most existing approaches focus only on avoiding PU activity when making sensing decisions. Since the myopic sensing strategy results in congestion and poor throughput, several collision-avoidance sensing approaches were investigated in the literature. However, they provide limited improvement. A channel-aware myopic sensing strategy that adapts the reward to the fading channel state information (CSI) of the SU link is proposed. This CSI varies over the CR spectrum and from one SU pair to another due to multipath and shadow fading, thus randomizing sensing decisions and increasing the network throughput. The proposed joint CSI adaptation at the medium access control (MAC) and physical layers provides large throughput gain over randomized sensing strategies and/or conventional adaptive transmission methods. The performance of the proposed CSI-aided sensing strategy is validated for practical network scenarios and demonstrated to be robust to CSI mismatch, sensing errors, and spatial channel correlation.}, booktitle={2013 IEEE 10th Consumer Communications and Networking Conference (CCNC)}, author={Lu, Yuan and Duel-Hallen, A.}, year={2013}, pages={466–71} }
 @article{jia_duel-hallen_hallen_2013, place={USA}, title={Data-Aided Noise Reduction for Long-Range Fading Prediction in Adaptive Modulation Systems}, volume={62}, ISSN={["1939-9359"]}, url={http://dx.doi.org/10.1109/TVT.2013.2241090}, DOI={10.1109/tvt.2013.2241090}, abstractNote={The long-range prediction (LRP) of fading signals enables adaptive transmission methods for rapidly varying mobile radio channels encountered in vehicular communications, but its performance is severely degraded by the additive noise and interference. A data-aided noise reduction (DANR) method is proposed to enhance the accuracy of fading prediction and to improve the spectral efficiency of adaptive modulation systems enabled by the LRP. The DANR includes an adaptive pilot transmission mechanism, robust noise reduction (NR), and decision-directed channel estimation. Due to improved prediction accuracy and low pilot rates, the DANR results in higher spectral efficiency than previously proposed NR techniques, which rely on oversampled pilots. It is also demonstrated that DANR-aided LRP increases the coding gain of adaptive trellis-coded modulation (ATCM). Finally, for low-to-medium signal-to-noise ratio (SNR) values, we show that LRP-enabled adaptive modulation performs better for realistic reflector configurations than for the conventional Jakes model (JM) data set.}, number={5}, journal={IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY}, author={Jia, Tao and Duel-Hallen, Alexandra and Hallen, Hans}, year={2013}, month={Jun}, pages={2358–2362} }
 @article{jia_duel-hallen_2012, place={USA}, title={Adaptive Bit-Interleaved Coded Modulation Based on the Expurgated Bound for Mobile Radio OFDM Systems Aided by Fading Prediction}, volume={60}, ISSN={["0090-6778"]}, url={http://dx.doi.org/10.1109/TCOMM.2012.062512.110022}, DOI={10.1109/tcomm.2012.062512.110022}, abstractNote={Adaptive bit-interleaved coded modulation (ABICM) is attractive for rapidly varying mobile radio channels due to its robustness to imperfect channel state information (CSI). A novel ABICM method that exploits the expurgated bound to maintain the target bit error rate (BER) for diverse CSI conditions is proposed and evaluated for an adaptive mobile radio orthogonal frequency division-multiplex (OFDM) system aided by the long-range fading prediction. It is demonstrated that ABICM is much less sensitive to prediction errors than adaptive modulation techniques that do not employ interleaving. However, reliable fading prediction is still necessary for ABICM to achieve high spectral efficiency for practical channel conditions.}, number={8}, journal={IEEE TRANSACTIONS ON COMMUNICATIONS}, author={Jia, Tao and Duel-Hallen, Alexandra}, year={2012}, month={Aug}, pages={2059–2064} }
 @article{wu_jia_calderbank_duel-hallen_hallen_2012, place={USA}, title={Enabling Code Diversity for Mobile Radio Channels using Long-Range Fading Prediction}, volume={11}, ISSN={["1558-2248"]}, url={http://dx.doi.org/10.1109/TWC.2012.101712.111884}, DOI={10.1109/twc.2012.101712.111884}, abstractNote={Code diversity integrates space-time coding with beamforming by using a small number of feedback bits to select from a family of space-time codes. Different codes lead to different induced channels at the receiver, where Channel State Information (CSI) is used to instruct the transmitter how to choose the code. Feedback can be combined with sub-optimal low complexity decoding of the component codes to match Maximum-Likelihood (ML) decoding performance of any individual code in the family. It can also be combined with ML decoding of the component codes to improve performance beyond ML decoding performance of any individual code. Prior analysis of code diversity did not take into account the effect of the mobile speed and the delay in the feedback channel. This paper demonstrates the practicality of code diversity in space-time coded systems by showing that performance gains based on instantaneous feedback are largely preserved when long-range prediction of time-varying correlated fading channels is employed to compensate for the effect of the feedback delay. To maintain prediction accuracy for realistic SNR, noise reduction that employs oversampled pilots is used prior to fading prediction. We also propose a robust low pilot rate method that utilizes interleaving to improve the spectral efficiency. Simulations are presented for two channel models: the conventional Jakes model and a realistic physical channel model where the parameters associated with the reflectors vary in time and the arrival rays have different strengths and asymmetric arrival angles.}, number={12}, journal={IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS}, author={Wu, Yiyue and Jia, Tao and Calderbank, Robert and Duel-Hallen, Alexandra and Hallen, Hans}, year={2012}, month={Dec}, pages={4362–4371} }
 @inproceedings{mehta_duel-hallen_wang_2012, place={Piscataway, NJ, USA}, title={Enabling adaptive rate and relay selection for 802.11 mobile ad hoc networks}, url={http://dx.doi.org/10.1109/ICC.2012.6363785}, DOI={10.1109/icc.2012.6363785}, abstractNote={Mobile ad hoc networks (MANETs) are self-configuring wireless networks that lack permanent infrastructure and are formed among mobile nodes on demand. Rapid node mobility results in dramatic channel variation, or fading, that degrades MANET performance. Employing channel state information (CSI) at the transmitter can improve the throughput of routing and medium access control (MAC) protocols for mobile ad hoc networks. Several routing algorithms in the literature explicitly incorporate the fading signal strength into the routing metric, thus selecting the routes with strong channel conditions. While these studies show that adaptation to the time-variant channel gain is beneficial in MANETs, they do not address the effect of the outdated fading CSI at the transmitter. For realistic mobile node speeds, the channel gain is rapidly varying, and becomes quickly outdated due the feedback delay. We analyze the link throughput of joint rate adaptation and adaptive relay selection in the presence of imperfect CSI. Moreover, for an 802.11 network that employs geographic opportunistic routing with adaptive rate and relay selection, we propose a novel method to reduce the effect of the feedback delay at the MAC layer in the presence of Rayleigh fading. This method exploits channel reciprocity and fading prediction and does not require significant modification to the existing 802.11 frame structure. Extensive network simulations demonstrate that the proposed approach significantly improves the throughput, delay, and packet delivery ratio for high mobile velocities relative to previously proposed approaches that employ outdated CSI at the transmitter.}, booktitle={IEEE International Conference on Communications (ICC 2012)}, author={Mehta, N. and Duel-Hallen, A. and Wang, Wenye}, year={2012}, pages={4150–4} }
 @inproceedings{li_wang_duel-hallen_2012, place={Piscataway, NJ, USA}, title={The latency of gaining -reliability for message dissemination in vehicle-to-vehicle networks}, url={http://dx.doi.org/10.1109/GLOCOM.2012.6504004}, DOI={10.1109/glocom.2012.6504004}, abstractNote={In many Vehicular Ad-hoc Network applications, such as hazard warning and traffic coordination, the message dissemination in unreliable and highly mobile network environment is a key challenge. In order to understand the relationship between dissemination latency and reliability, we analyze the latency of gaining α-reliability that a node correctly receives a message with probability larger than α (0 < α< 1). Under a 1-Dimensional (1-D) network scenario with unreliable channel and constrained vehicle mobility, we derive the minimum latency of gaining almost sure α-reliability, denoted as tmin(α). Besides dissemination reliability requirement α, tmin(α) also depends on node's original distance from the source, node mobility, channel reliability, and traffic flow. Numerical analysis discloses several interesting insights that 1) tmin(α) is dominated by the first attempt to send the message to a destination, 2) node mobility has little impact on tmin(α) in emergency information dissemination, and 3) transmission range and node density greatly affect dissemination latency and reliability.}, booktitle={GLOBECOM 2012 - 2012 IEEE Global Communications Conference}, author={Li, Y. J. and Wang, Wenye and Duel-Hallen, A.}, year={2012}, pages={5550–5} }
 @inproceedings{jia_duel-hallen_2009, place={Piscataway, NJ, USA}, title={Improved Adaptive Bit-Interleaved Coded Modulation for Mobile Radio OFDM Systems Aided by Fading Prediction}, url={http://dx.doi.org/10.1109/ACSSC.2009.5470169}, DOI={10.1109/ACSSC.2009.5470169}, abstractNote={Adaptive bit-interleaved coded modulation (ABICM) is attractive for rapidly varying mobile radio channels due to its robustness to imperfect channel state information (CSI) at the transmitter. Novel ABCIM method based on the expurgated bound is proposed. This method improves upon previously investigated ABICM techniques since it is able to maintain the target bit error rate for diverse CSI conditions. Spectral efficiencies of the proposed ABICM method, adaptive trellis-coded modulation, and uncoded adaptive modulation are compared for an adaptive mobile radio orthogonal frequency division-multiplex (OFDM) system aided by the long-range fading prediction. It is demonstrated that ABICM is much less sensitive to prediction errors than the other two adaptive modulation techniques, which do not employ interleaving, but reliable fading prediction is still necessary to achieve high spectral efficiency of ABICM for practical channel conditions.}, booktitle={2009 43rd Asilomar Conference on Signals, Systems and Computers}, author={Jia, Tao and Duel-Hallen, A.}, year={2009}, pages={68–72} }
 @article{jia_duel-hallen_2009, title={Improved Channel Allocation for Multicarrier CDMA with Adaptive Frequency Hopping and Multiuser Detection}, volume={57}, ISSN={["1558-0857"]}, DOI={10.1109/TCOMM.2009.11.070575}, abstractNote={Multicarrier code-division multiple access (MCCDMA) system with adaptive frequency hopping (AFH) has attracted attention of researchers due to its excellent spectral efficiency. A suboptimal water-filling (WF) channel allocation algorithm was previously proposed for the reverse link of this system. To overcome the limitations of the WF algorithm in the presence of fading-induced near-far problem, a new allocation algorithm is proposed and demonstrated to improve performance when the conventional matched filter (MF) receiver is employed. Moreover, the allocation methods are extended to accommodate multiuser detectors (MUDs) at the receiver for MC-CDMA system with AFH. It is demonstrated that the combination of the improved allocation algorithm and the linear MUDs is very efficient in mitigating the fading and multi-access interference (MAI) for realistic mobile radio channels with correlated subcarriers, channel state information (CSI) mismatch, and imperfect power control. Numerical results show that the proposed adaptive transmission method has much greater system capacity than conventional non-adaptive MC direct-sequence (DS)-CDMA system.}, number={11}, journal={IEEE TRANSACTIONS ON COMMUNICATIONS}, author={Jia, Tao and Duel-Hallen, Alexandra}, year={2009}, month={Nov}, pages={3389–3396} }
 @inproceedings{mehta_duel-hallen_hallen_2009, place={Piscataway, NJ, USA}, title={Template design and propagation gain for multipath UWB channels with per-path frequency-dependent distortion}, url={http://dx.doi.org/10.1109/MILCOM.2009.5380076}, DOI={10.1109/MILCOM.2009.5380076}, abstractNote={Due to the large bandwidth allocation, Ultra-Wideband (UWB) channels exhibit frequency-dependent distortion of individual multipath components. This per-path distortion is particularly significant in outdoor UWB applications, where line-of-sight (LOS) or non-distorted reflected signals might not be available at the receiver, and the dominant propagation mechanisms involve shadowing (diffraction) or reflection by small objects (e.g. signs or lamp-posts). In this paper, a physical model is employed in the design of robust correlation receiver templates for outdoor single and multipath impulse radio channels characterized by per-path distortion. It is demonstrated that receivers which employ a set of partial derivatives templates are near-optimal in terms of energy capture while the simple transmit pulse template provides excellent complexity-performance trade-offs for most practical scenarios. Moreover, iterative receiver structures that maintain the energy capture in the presence of overlapping multipath components are investigated. Finally, a large gap between the propagation gains of the transmit pulses in the lower and upper bands of the FCC spectrum is characterized for several propagation mechanisms.*}, booktitle={MILCOM 2009 - 2009 IEEE Military Communications Conference}, author={Mehta, N. and Duel-Hallen, A. and Hallen, H.}, year={2009}, pages={7 pp. -} }
 @inproceedings{jia_duel-hallen_hallen_2008, place={Piscataway, NJ, USA}, title={Improved long-range prediction with data-aided noise reduction for adaptive modulation systems}, url={http://dx.doi.org/10.1109/CISS.2008.4558694}, DOI={10.1109/CISS.2008.4558694}, abstractNote={A novel data-aided noise reduction (DANR) method is proposed to enhance the accuracy of long-range prediction (LRP) for wireless fading channels, thereby improving the spectral efficiency (SE) of adaptive modulation (AM) system enabled by the LRP. This method includes an adaptive pilot transmission mechanism, robust noise reduction and decision-directed channel estimation. An improved practical AM scheme is used to test the proposed DANR method. Since this method maintains low pilot rates, it results in higher SE than previously proposed noise reduction (NR) techniques, which rely on oversampled pilots. These conclusions are confirmed for practical prediction ranges using the standard Jakes model and our realistic physical model.}, booktitle={42nd Annual Conference on Information Sciences and Systems (CISS 2008)}, author={Jia, Tao and Duel-Hallen, A. and Hallen, H.}, year={2008}, pages={1161–6} }
 @inproceedings{jia_duel-hallen_hallen_2008, place={Piscataway, NJ, USA}, title={Performance of adaptive coded modulation enabled by long-range fading prediction with data-aided noise reduction}, url={http://dx.doi.org/10.1109/MILCOM.2008.4753263}, DOI={10.1109/MILCOM.2008.4753263}, abstractNote={Performance of uncoded adaptive modulation (UAM) and adaptive coded modulation (ACM) enabled by the long-range prediction (LRP) that utilizes data-aided noise reduction (DANR) is investigated for rapidly varying mobile radio channels. Due to improved prediction accuracy and low pilot rate, the DANR-aided LRP outperforms previously proposed prediction methods that rely on oversampled pilots to achieve noise reduction (NR). While ACM is more sensitive to prediction errors than UAM, utilization of DANR substantially increases its spectral efficiency (SE) relative to previously proposed methods. The set of SNR values and prediction ranges where positive coding gain is achieved by ACM enabled by DANR-aided LRP is determined. It is also demonstrated that adaptive modulation (AM) aided by LRP has better performance for the realistic physical model than for the Jakes model in the practical SNR range.}, booktitle={MILCOM 2008 - 2008 IEEE Military Communications Conference}, author={Jia, Tao and Duel-Hallen, A. and Hallen, H.}, year={2008}, pages={7 pp. -} }
 @article{jia_duel-hallen_2008, title={Performance of improved channel allocation for multicarrier CDMA with adaptive frequency hopping and multiuser detection}, ISBN={["978-1-4244-2074-2"]}, ISSN={["1550-3607"]}, DOI={10.1109/icc.2008.896}, abstractNote={Subchannel allocation for the reverse link of multi-carrier code-division multiplex-access (MC-CDMA) system with adaptive frequency hopping (AFH) is investigated. An efficient allocation method that can be employed with the matched filter (MF) receiver as well as with multiuser detectors (MUDs) by exploiting the appropriate signal to interference and noise ratio (SINR) analysis is described. It is demonstrated that combined improved subcarrier allocation and the linear decorrelating detector (LDD) are very efficient in mitigating multiple-access interference (MAI), resulting in much larger system capacity than for a non-adaptive MC direct-sequence (DS)-CDMA system. This conclusion is confirmed for realistic fading channels with correlated subcarriers and imperfect channel state information (CSI) at the transmitter.}, journal={2008 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS, PROCEEDINGS, VOLS 1-13}, author={Jia, Tao and Duel-Hallen, Alexandra}, year={2008}, pages={4780–4784} }
 @inproceedings{jia_duel-hallen_2008, place={Piscataway, NJ, USA}, title={Performance of improved channel allocation for multicarrier CDMA with adaptive frequency hopping and multiuser detection}, booktitle={2008 International Conference on Communications}, author={Jia, Tao and Duel-Hallen, A.}, year={2008}, pages={5696–700} }
 @article{lei_due-hallen_hallen_2008, title={Reliable adaptive modulation and interference mitigation for mobile radio slow frequency hopping channels}, volume={56}, ISSN={["1558-0857"]}, url={http://dx.doi.org/10.1109/TCOMM.2008.040662}, DOI={10.1109/TCOMM.2008.040662}, abstractNote={The long range fading prediction algorithm for Slow Frequency Hopping (SFH) systems is proposed and demonstrated to enable combined adaptive modulation and adaptive frequency diversity to mitigate the effects of fading and partial-band interference. Significant performance gains are demonstrated relative to non-adaptive methods in realistic mobile radio SFH channels where the total bandwidth does not exceed approximately 15 times the coherence bandwidth.}, number={3}, journal={IEEE TRANSACTIONS ON COMMUNICATIONS}, author={Lei, Ming and Due-Hallen, Alexandra and Hallen, Hans}, year={2008}, month={Mar}, pages={352–355} }
 @article{lei_duel-hallen_hallen_2008, place={USA}, title={Reliable adaptive modulation and interference mitigation for mobile radio slow frequency hopping channels}, volume={56}, number={3}, journal={IEEE Trans. Commun. (USA)}, author={Lei, Ming and Duel-Hallen, A. and Hallen, H.}, year={2008}, month={Mar}, pages={352–5} }
 @article{duel-hallen_2007, title={Fading channel prediction for mobile radio adaptive transmission systems}, volume={95}, ISSN={["1558-2256"]}, DOI={10.1109/JPROC.2007.904443}, abstractNote={Adaptive transmission methods can potentially aid the achievement of high data rates required for mobile radio multimedia services. To realize this potential, the transmitter needs accurate channel state information (CSI) for the upcoming transmission frame. In most mobile radio systems, the CSI is estimated at the receiver and fed back to the transmitter. However, unless the mobile speed is very low, the estimated CSI cannot be used directly to select the parameters of adaptive transmission systems, since it quickly becomes outdated due to the rapid channel variation caused by multipath fading. To enable adaptive transmission for mobile radio systems, prediction of future fading channel samples is required. Several fundamental issues arise in the design and testing of fading prediction algorithms for adaptive transmission systems. These include complexity, robustness, choice of an appropriate channel model for algorithm validation, channel estimation and noise reduction required for reliable prediction, and design and analysis of adaptive transmission methods aided by fading prediction algorithms. We use these criteria in the review of recent advances in the area of fading channel prediction. We also demonstrate that reliable fading prediction makes adaptive transmission feasible in diverse wireless communication systems.}, number={12}, journal={PROCEEDINGS OF THE IEEE}, author={Duel-Hallen, Alexandra}, year={2007}, month={Dec}, pages={2299–2313} }
 @inproceedings{duel-hallen_lei_yang_hallen_2006, place={Anaheim, CA, USA}, title={Feasibility of adaptive transmission for multicarrier and frequency hopping mobile radio systems}, booktitle={Proceedings of the Sixth IASTED International Multi-Conference on Wireless and Optical Communications}, author={Duel-Hallen, A. and Lei, Ming and Yang, Tung-Sheng and Hallen, H.}, year={2006}, pages={52–7} }
 @article{duel-hallen_hallen_yang_2006, place={USA}, title={Long range prediction and reduced feedback for mobil radio adaptive OFDM systems}, volume={5}, ISSN={["1558-2248"]}, url={http://dx.doi.org/10.1109/TWC.2006.04219}, DOI={10.1109/TWC.2006.04219}, abstractNote={Adaptive orthogonal frequency division multiplexing (AOFDM) modulation is a promising technique for achieving high data rates required for wireless multimedia services. To accomplish efficient adaptive channel loading, the channel state information (CSI) needs to be fed back to the transmitter. Since the fading channel varies rapidly for fast vehicle speeds, long range fading prediction (LRP) is required for mobile radio AOFDM to insure reliable adaptation. We use past channel observations to predict future CST and perform adaptive bit and power allocation for the OFDM system. We derive the minimum mean-square-error (MMSE) long-range channel prediction that utilizes the time and frequency domain correlation functions of the Rayleigh fading channel. Since the channel statistics are usually unknown, robust prediction methods that do not require the knowledge of the correlation functions are developed. Statistical model of the prediction error is created and used in the design of reliable adaptive modulation. In addition, several methods that significantly reduce the feedback load for mobile radio AOFDM systems are developed and compared. We use a standard sum-of-sinusoids model and our realistic physical model to validate performance of proposed methods. Simulation results demonstrate reliable performance and robustness of the proposed techniques, thus validating feasibility of AOFDM for rapidly varying mobile radio channels}, number={10}, journal={IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS}, author={Duel-Hallen, Alexandra and Hallen, Hans and Yang, Tung-Sheng}, year={2006}, month={Oct}, pages={2723–2733} }
 @misc{elezabi_duel-hallen_2006, title={Single-user decoder metrics for subtractive interference cancellation detectors in code-division multiple-access (CDMA) communication systems with time dependence variance residual multiple-access interference (RMAI)}, volume={7,035,317}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Elezabi, A. and Duel-Hallen, A.}, year={2006} }
 @inproceedings{lei_duel-hallen_hallen_2005, place={Piscataway, NJ, USA}, title={Enabling adaptive modulation and interference mitigation for slow frequency hopping communications}, booktitle={The Sixth IEEE International Workshop on Signal Processing Advances in Wireless Communications (IEEE Cat. No. 05EX992)}, author={Lei, M. and Duel-Hallen, A. and Hallen, H.}, year={2005}, pages={348–52} }
 @inproceedings{liu_duel-hallen_2005, title={Performance Analysis of Tomlinson-Harashima Multiuser Precoding in Multipath CDMA Channels}, booktitle={Proc. 4GMF05}, author={Liu, J. and Duel-Hallen, A.}, year={2005}, month={Jul} }
 @article{guncavdi_duel-hallen_2005, title={Performance analysis of space-time transmitter diversity techniques for WCDMA using long range prediction}, volume={4}, DOI={10.1109/FWC.2004.840222}, number={1}, journal={IEEE Transactions on Wireless Communications}, author={Guncavdi, S. and Duel-Hallen, Alexandra}, year={2005}, pages={40–45} }
 @article{guncavdi_duel-hallen_2005, place={USA}, title={Performance analysis of space-time transmitter diversity techniques for WCDMA using long range prediction}, volume={4}, url={http://dx.doi.org/10.1109/TWC.2004.840222}, DOI={10.1109/TWC.2004.840222}, abstractNote={Transmitter diversity in the downlink of code-division multiple-access (CDMA) systems achieves similar performance gains to the mobile-station receiver diversity without the complexity of a mobile-station receiver antenna array. Pre-RAKE precoding at the transmitter can be employed to achieve the multipath diversity without the need of the RAKE receiver at the mobile station. We examine feasibility of several transmitter diversity techniques and precoding for the third-generation wideband CDMA (WCDMA) systems. In particular, selective transmit diversity, transmit adaptive array and space-time pre-RAKE (STPR) techniques are compared. It is demonstrated that the STPR method is the optimal method to combine antenna diversity and temporal precoding. This method achieves the gain of maximum ratio combining of all space and frequency diversity branches when perfect channel state information is available at the transmitter. We employ the long range fading prediction algorithm to enable transmitter diversity techniques for rapidly time varying multipath fading channels.}, number={1}, journal={IEEE Trans. Wirel. Commun. (USA)}, author={Guncavdi, S. and Duel-Hallen, A.}, year={2005}, month={Jan}, pages={40–5} }
 @inproceedings{yang_duel-hallen_hallen_2004, place={Piscataway, NJ, USA}, title={Enabling adaptive OFDM for mobile radio channels}, volume={Vol. 2}, booktitle={MILCOM 2004. 2004 IEEE Military Communications Conference (IEEE Cat. No. 04CH37621)}, author={Yang, Tung-Sheng and Duel-Hallen, A. and Hallen, H.}, year={2004}, pages={704–10} }
 @article{elezabi_duel-hallen_2004, place={USA}, title={Improved Viterbi decoder metrics for two-stage detectors in DS-CDMA}, volume={3}, ISSN={["1558-2248"]}, url={http://dx.doi.org/10.1109/TWC.2004.833489}, DOI={10.1109/TWC.2004.833489}, abstractNote={Modified branch metrics are proposed for single-user Viterbi decoders in two-stage detectors for convolutionally-encoded code-division multiple-access (CDMA) systems with random spreading sequences. The modifications are based on modeling the residual multiple-access interference (RMAI) after subtractive interference cancellation as conditionally Gaussian with time-dependent variance, where the conditioning is on the time-varying user crosscorrelations. A novel estimate of the variance of the total RMAI is presented, and used in the proposed branch metrics. Significant performance gains are demonstrated over the Euclidean branch metric of the standard Viterbi decoder.}, number={5}, journal={IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS}, author={Elezabi, A and Duel-Hallen, A}, year={2004}, month={Sep}, pages={1399–1404} }
 @inproceedings{liu_duel-hallen_2004, place={Piscataway, NJ, USA}, title={Nonlinear multiuser precoding for downlink DS-CDMA systems over multipath fading channels}, volume={vol.1}, booktitle={GLOBECOM '04. IEEE Global Telecommunications Conference (IEEE Cat. No.04CH37615)}, author={Liu, Jia and Duel-Hallen, A.}, year={2004}, pages={277–81} }
 @article{yang_duel-hallen_hallen_2004, place={USA}, title={Reliable adaptive modulation aided by observations of another fading channel}, volume={52}, ISSN={["1558-0857"]}, url={http://dx.doi.org/10.1109/TCOMM.2004.826369}, DOI={10.1109/TCOMM.2004.826369}, abstractNote={Adaptive transmission techniques, such as adaptive modulation and coding, adaptive power control, adaptive transmitter antenna diversity, etc., generally require precise channel estimation and feedback of channel state information (CSI). For fast vehicle speeds, reliable adaptive transmission also requires long-range prediction of future CSI, since the channel conditions are rapidly time variant. In this paper, we propose using past channel observations of one carrier to predict future CSI and perform adaptive modulation without feedback for another correlated carrier. We derive the minimum mean-square error (MMSE) long-range channel prediction that uses the time- and frequency-domain correlation function of the Rayleigh fading channel. An adaptive MMSE prediction method is also proposed. A statistical model of the prediction error that depends on the frequency and time correlation is developed and is used in the design of reliable adaptive modulation methods. We use a standard stationary fading channel model (Jakes model) and a novel physical channel model to test our algorithm. Significant gains relative to nonadaptive techniques are demonstrated for sufficiently correlated channels and realistic prediction range.}, number={4}, journal={IEEE TRANSACTIONS ON COMMUNICATIONS}, author={Yang, TS and Duel-Hallen, A and Hallen, H}, year={2004}, month={Apr}, pages={605–611} }
 @inproceedings{yang_duel-hallen_hallen_2004, place={Boulder, CO}, title={Validation of Adaptive Transmission for Realistic Single- and Multi-Carrier Mobile Radio Channels}, note={– An invited paper}, booktitle={Proceedings of URSI'04, Special Session on Propagation Effects in Wireless Communications Channels}, author={Yang, T. S. and Duel-Hallen, A. and Hallen, H.}, year={2004}, pages={75} }
 @inproceedings{hu_duel-hallen_hallen_2002, place={Piscataway, NJ, USA}, title={Adaptive modulation for transmitter antenna diversity mobile radio systems}, url={http://dx.doi.org/10.1109/ISIT.2002.1023377}, DOI={10.1109/ISIT.2002.1023377}, abstractNote={Adaptive transmission techniques such as adaptive modulation and transmitter antenna diversity have been proposed for mobile wireless systems to satisfy high data-rate service requirements. In rapidly time variant channels, these methods need the knowledge of future fading conditions and therefore require accurate long range fading prediction. We investigate three combined adaptive modulation and transmitter diversity schemes in conjunction with our previously proposed long-range fading channel prediction (LRP) algorithm. It is demonstrated that the novel combined schemes achieve significantly higher data rates than conventional adaptive modulation methods when aided by the LRP. Performance-complexity trade-off for several combined adaptive methods is examined. In addition to utilizing the Jakes fading model to test the proposed methods, we validate the LRP for antenna diversity systems using a novel realistic fading channel model.}, booktitle={Proceedings 2002 IEEE International Symposium on Information Theory (Cat. No.02CH37371)}, author={Hu, Shengquan and Duel-Hallen, A. and Hallen, H.}, year={2002}, pages={105 -} }
 @inproceedings{yang_duel-hallen_2002, place={Piscataway, NJ, USA}, title={Adaptive modulation using outdated samples of another fading channel}, volume={vol.1}, url={http://dx.doi.org/10.1109/WCNC.2002.993542}, DOI={10.1109/WCNC.2002.993542}, abstractNote={Adaptive transmission techniques, such as adaptive modulation and coding, adaptive power control, adaptive transmitter antenna diversity, etc., generally require precise channel estimation and channel state information (CSI) feedback. For fast vehicle speeds, reliable adaptive transmission also requires prediction of future CSI since the channel conditions are rapidly time-variant. We propose to use past channel observations of one carrier to predict future CSI and perform adaptive modulation without feedback for another correlated carrier. A statistical model of the prediction error that depends on the frequency and time correlation is developed and is used in the design of reliable adaptive modulation methods. Significant gains relative to non-adaptive techniques are demonstrated for sufficiently correlated channels and realistic prediction range.}, booktitle={2002 IEEE Wireless Communications and Networking Conference Record. WCNC 2002 (Cat. No.02TH8609)}, author={Yang, Tung-Sheng and Duel-Hallen, A.}, year={2002}, pages={477–81} }
 @inbook{duel-hallen_2003, title={Fading Channels}, booktitle={the Wiley Encyclopedia of Telecommunications}, publisher={John Wiley&Sons, Inc.}, author={Duel-Hallen, A.}, editor={Proakis, J. G.Editor}, year={2003}, pages={781–789} }
 @inproceedings{ming_duel-hallen_2003, place={Monticello, Illinois}, title={Long Range Channel Prediction and Adaptive Transmission for Frequency Hopping Communications}, number={V.C}, booktitle={Proceedings of 41st Annual Allerton Conference on Communication, Control and Computing}, author={Ming, L. and Duel-Hallen, A.}, year={2003}, month={Oct}, pages={1–10} }
 @inproceedings{guncavdi_duel-hallen_2003, place={Baltimore, MD}, title={Pre-RAKE Multiuser Transmitter Precoding for DS/CDMA Systems}, number={169}, booktitle={Proceedings of 37th Annual Conference on Information Sciences and Systems, CISS'03}, author={Guncavdi, S. and Duel-Hallen, A.}, year={2003}, month={Mar}, pages={1–6} }
 @inproceedings{yang_duel-hallen_hallen_2002, place={Piscataway, NJ, USA}, title={Reliable adaptive modulation using long-range prediction at a different carrier frequency}, url={http://dx.doi.org/10.1109/ISIT.2002.1023631}, DOI={10.1109/ISIT.2002.1023631}, abstractNote={For fast vehicle speeds, reliable adaptive transmission requires prediction of future channel state information (CSI) since the channel conditions are rapidly time-variant. We propose to use past channel observations of one carrier to predict future CSI and perform adaptive modulation for another correlated carrier. A statistical model of the prediction error that depends on the frequency and time correlation is developed and is used in the design of reliable adaptive modulation methods. Significant gains relative to nonadaptive techniques are demonstrated for sufficiently correlated channels and realistic prediction range. Both Jakes (1974) fading model and a novel realistic physical model of frequency selective fading are used to validate performance of the proposed method.}, booktitle={Proceedings 2002 IEEE International Symposium on Information Theory (Cat. No.02CH37371)}, author={Yang, Tung-Sheng and Duel-Hallen, A. and Hallen, H.}, year={2002}, pages={359 -} }
 @inproceedings{guncavdi_duel-hallen_2003, place={Piscataway, NJ, USA}, title={Space-time pre-RAKE multiuser transmitter precoding for DS-CDMA systems}, volume={Vol.4}, booktitle={2003 IEEE 58th Vehicular Technology Conference. VTC 2003-Fall (IEEE Cat. No.03CH37484)}, author={Guncavdi, S. and Duel-Hallen, A.}, year={2003}, pages={2411–15} }
 @inproceedings{liu_duel-hallen_2003, place={Baltimore, MD}, title={Tomlinson -- Harashima Transmitter Precoding for Synchronous Multiuser Communications}, number={60}, booktitle={Proceedings of 37th Annual Conference on Information Sciences and Systems, CISS'03}, author={Liu, J. and Duel-Hallen, A.}, year={2003}, month={Mar}, pages={1–6} }
 @inproceedings{hu_eyceoz_duel-hallen_hallen_1999, place={Piscataway, NJ, USA}, title={Transmitter antenna diversity and adaptive signaling using long range prediction for fast fading DS/CDMA mobile radio channels}, volume={vol.2}, url={http://dx.doi.org/10.1109/WCNC.1999.796779}, DOI={10.1109/WCNC.1999.796779}, abstractNote={Previously, the authors introduced a novel algorithm for long range prediction of flat fading channels that can reliably predict future fading coefficients far beyond the coherence time. This prediction capability provides enabling technology for power and bandwidth efficient adaptive modulation and coding methods. In this paper, we extend our results to the direct sequence code division multiple access (DS/CDMA) channels. It is demonstrated that frequency selective channels encountered in CDMA can also be predicted far ahead, and that the proposed prediction methods can be combined with RAKE receivers. In addition, we utilize prediction to improve performance of the selective transmitter diversity system proposed for the third generation CDMA.}, note={– An invited paper}, booktitle={WCNC. 1999 IEEE Wireless Communications and Networking Conference (Cat. No.99TH8466)}, author={Hu, Shengquan and Eyceoz, T. and Duel-Hallen, A. and Hallen, H.}, year={1999}, pages={824–8} }
 @inproceedings{hallen_duel-hallen_hu_yang_lei_2002, place={Piscataway, NJ, USA}, title={A physical model for wireless channels to provide insights for long range prediction}, volume={vol.1}, booktitle={2002 Military Communications Conference. Proceedings (Cat. No.02CH37397)}, author={Hallen, H. and Duel-Hallen, A. and Hu, Shengquan and Yang, Tung-Shen and Lei, Ming}, year={2002}, pages={627–31} }
 @inproceedings{hu_duel-hallen_hallen_2000, place={Piscataway, NJ, USA}, title={Adaptive modulation using long range prediction for flat Rayleigh fading channels}, url={http://dx.doi.org/10.1109/ISIT.2000.866451}, DOI={10.1109/ISIT.2000.866451}, abstractNote={We theoretically analyze the statistical behavior of prediction errors generated by our previously proposed (Duel-Hallen et al. 2000) long range prediction algorithm, and investigate adaptive modulation design using predicted channel state information (CSI). Both numerical and simulation results show that accurate prediction of the fading channel far ahead makes adaptive transmission feasible for rapidly time-varying mobile radio channels.}, booktitle={2000 IEEE International Symposium on Information Theory (Cat. No.00CH37060)}, author={Hu, Shengquan and Duel-Hallen, A. and Hallen, H.}, year={2000}, pages={159 -} }
 @article{cherubini_cioffi_duel-hallen_poor_tranter_2002, title={Guest Editorial - Multiuser detection techniques with application to wired and wireless communications systems II}, volume={20}, ISSN={["0733-8716"]}, DOI={10.1109/JSAC.2002.983334}, abstractNote={M ULTIUSER detection (MUD) techniques hold the promise that future multiple-access communications systems will be able to use all the dormant capacity that is potentially available in existing communications networks. This second issue devoted to the topic of MUD techniques 1 features 22 contributions that address key areas for the development of the field. In wireless transmission systems, MUD often must be performed in the presence of possible rapid variations of the channel. In such situations, receiver complexity is an issue, and this is the focus of the first group of papers in this issue. In " Reduced and Differential Parallel Interference Cancellation for CDMA Systems, " Nahler et al. investigate various parallel architectures for interference cancellation. The paper, " A Low-Complexity Combined Antenna Array and Interference Cancellation DS-CDMA Receiver in Multipath Fading Channels , " by Mohamed and Dunham combines beamforming to reduce co-channel interference with parallel interference cancellation to mitigate in-beam multiple-access interference, to result in a low-complexity system for multiuser reception in frequency-selective channels. Lee and Kim consider the gambit of choosing a very simple detector that exploits the characteristics of CDMA signals in " A One-Shot LDD With Pre-SDC/Post-MRC for Random CDMA Over Asynchronous Rayleigh Channels. " Two suboptimal multiuser detectors based on the maximum-likelihood criterion are presented in " Reduced State Maximum-Likelihood Multiuser Detection for Down-link TD-CDMA Systems, " by Benvenuto et al. It is shown that these detectors perform much better than the zero-forcing and the minimum-mean-square-error detectors, while maintaining a complexity that is proportional to the number of users. Castoldi and Kobayashi investigate linear interference cancellation for the downlink in " Co-Channel Interference Mitigation Detectors for Multirate Transmission in TD-CDMA Systems. " The proposed receivers employ tunable-complexity structures that cancel intracell interference, and treat intercell interference differently, depending on the operating environment. A unifying framework for a new class of receivers that employ linearly constrained interference cancellation is presented in " Interference Subspace Rejection: A Framework Publisher Item Identifier S 0733-8716(02)00988-5. 1 The reference for the first issue is " Multiuser detection techniques with application to wired and wireless communications systems I, " IEEE J. Select. for Multiuser Detection in Wideband CDMA " by Affes et al. These detectors operate in various modes, ranging from linear receivers to interference cancellers. In addition to interference rejection, they perform space and time diversity combining, array processing, and synchronization and can operate in multiple mixed-traffic scenarios. …}, number={2}, journal={IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS}, author={Cherubini, G and Cioffi, JM and Duel-Hallen, A and Poor, HV and Tranter, WH}, year={2002}, month={Feb}, pages={233–236} }
 @inproceedings{wu_duel-hallen_1996, place={New York, NY, USA}, title={On the performance of coherent and noncoherent multiuser detectors for mobile radio CDMA channels}, volume={vol.1}, url={http://dx.doi.org/10.1109/ICUPC.1996.557757}, DOI={10.1109/ICUPC.1996.557757}, abstractNote={We investigate the performance of several suboptimal multiuser detectors for rapidly time varying mobile radio channels. A modified Jakes (1974) model is used to simulate a realistic mobile fading channel. The use of the Kalman filter for this channel model is examined. We also analyze the performance of several noncoherent multiuser detectors. Analysis and simulation results indicate that the decorrelator is more robust than other considered multiuser detectors.}, booktitle={Gateway to the Twenty First Century. International Conference on Universal Personal Communications. 1996 5th IEEE International Conference on Universal Personal Communications Record (Cat. No.96TH8185)}, author={Wu, Hsin-Yu and Duel-Hallen, A.}, year={1996}, pages={76–80} }
 @inproceedings{elezabi_duel-hallen_1998, place={New York, NY, USA}, title={Post-decoding interference cancelation for coded CDMA systems}, url={http://dx.doi.org/10.1109/ISIT.1998.708887}, DOI={10.1109/ISIT.1998.708887}, abstractNote={The performance of two-stage post-decoding interference cancelation schemes for coded CDMA systems are analyzed over fading channels. Upper bounds on error probability and approximations are derived and their tightness assessed.}, booktitle={Proceedings. 1998 IEEE International Symposium on Information Theory (Cat. No.98CH36252)}, author={Elezabi, A.Y. and Duel-Hallen, A.}, year={1998}, pages={282 -} }
 @article{fulghum_molnar_duel-hallen_2002, place={USA}, title={The jakes fading model for antenna arrays incorporating azimuth spread}, volume={51}, ISSN={["1939-9359"]}, url={http://dx.doi.org/10.1109/TVT.2002.801742}, DOI={10.1109/TVT.2002.801742}, abstractNote={A new method for simulating the multiplicative fading of the narrow-band, flat wireless channel for antenna array receivers is presented. The new approach produces a set of fading waveforms, one waveform associated with each receiver element, in which the waveforms are appropriately correlated to take into account the spread, or dispersion, in the azimuth (arrival angle) of the received signal. The new method is an extension of the Jakes (1974) method of simulating fading in which the appropriate correlation of the set of waveforms is accomplished by directly considering the azimuth of scatterers in a particular distribution about the mobile transmitter. The models used for this cluster of scatterers are a ring and a disk of scatterers. Further modifications of the disk model permit the generation of fading waveforms which are correlated in a manner which reflect actual field measurements of azimuth dispersion. Analytical correlation of these models is reviewed for purposes of verification with the waveforms generated by the method.}, number={5}, journal={IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY}, author={Fulghum, TL and Molnar, KJ and Duel-Hallen, A}, year={2002}, month={Sep}, pages={968–977} }
 @inproceedings{guncavdi_duel-hallen_2001, title={A Novel Space-Time Pre-RAKE Transmitter Diversity Method for W-CDMA Using Long Range Prediction}, volume={1}, booktitle={Proceedings of 35th Annual Conference on Information Sciences and Systems, CISS'01}, author={Guncavdi, S. and Duel-Hallen, A.}, year={2001}, month={Mar}, pages={32–37} }
 @article{cherubini_cioffi_duel-hallen_poor_2001, title={Multiuser detection techniques with application to wired and wireless communications systems I}, volume={19}, ISSN={["0733-8716"]}, DOI={10.1109/JSAC.2001.942505}, number={8}, journal={IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS}, author={Cherubini, G and Cioffi, JM and Duel-Hallen, A and Poor, HV}, year={2001}, month={Aug}, pages={1425–1428} }
 @inproceedings{hu_duel-hallen_hallen_2001, place={Banff, Canada}, title={Selective Transmitter Diversity and Adaptive Power Control for Realistic Mobile Radio Channels}, booktitle={Proceedings of WOC'2001}, author={Hu, S. and Duel-Hallen, A. and Hallen, H.}, year={2001}, pages={178–182} }
 @inproceedings{hu_duel-hallen_hallen_2000, title={Long-Range Prediction Makes Adaptive Modulation Feasible for Realistic Mobile Radio Channels}, booktitle={Proc. of 34rd Annual Conference on Information Sciences and Systems CISS'2000}, author={Hu, S. and Duel-Hallen, A. and Hallen, H.}, year={2000}, pages={WP4–7 - WP4–13} }
 @article{duel-hallen_hu_hallen_2000, title={Long-range prediction of fading signals - Enabling adapting transmission for mobile radio channels}, volume={17}, ISSN={["1558-0792"]}, url={http://dx.doi.org/10.1109/79.841729}, DOI={10.1109/79.841729}, abstractNote={It was previously proposed to adapt several transmission methods, including modulation, power control, channel coding, and antenna diversity to rapidly time variant fading channel conditions. Prediction of the channel coefficients several tens-to-hundreds of symbols ahead is essential to realize these methods in practice. We describe a novel adaptive long-range fading channel prediction algorithm (LRP) and its utilization with adaptive transmission methods. The LRP is validated for standard stationary fading models and tested with measured data and with data produced by our novel realistic physical channel model. Both numerical and simulation results show that long-range prediction makes adaptive transmission techniques feasible for mobile radio channels.}, note={– An invited paper}, number={3}, journal={IEEE SIGNAL PROCESSING MAGAZINE}, author={Duel-Hallen, A and Hu, SQ and Hallen, H}, year={2000}, month={May}, pages={62–75} }
 @article{wu_duel-hallen_2000, title={Multiuser detectors with disjoint Kalman channel estimators for synchronous CDMA mobile radio channels}, volume={48}, ISSN={["0090-6778"]}, DOI={10.1109/26.843185}, abstractNote={We compare performance of several multiuser detectors for differentially encoded data combined with simple, disjoint, decision-directed Kalman channel estimators over flat Rayleigh fading channels. Simpler detectors with noncoherent differential detection are also compared. Different performance trends relative to the case of perfect channel estimation are observed. We find that in the presence of channel mismatch, the linear decorrelator is the most robust detector in terms of the bit-error rate and the near-far resistance. Parameter adjustment for fading channel modeling and estimation in the decision-directed mode are also discussed.}, number={5}, journal={IEEE TRANSACTIONS ON COMMUNICATIONS}, author={Wu, PHY and Duel-Hallen, A}, year={2000}, month={May}, pages={752–756} }
 @inproceedings{hu_hallen_duel-hallen_1999, title={Adaptive Power Control Using Long Range Prediction for Realistic Fast Fading Channel Models and Measured Data}, url={https://pdfs.semanticscholar.org/c77a/2149dd49861fd5f3c1c54db7a23fa549f0d6.pdf}, booktitle={5th International Symposium on Communication Theory and Application ISCTA'99}, author={Hu, S. and Hallen, H. and Duel-Hallen, A.}, year={1999}, pages={118–120} }
 @inproceedings{eyceoz_hu_duel-hallen_hallen_1999, place={Piscataway, NJ, USA}, title={Adaptive prediction, tracking and power adjustment for frequency non-selective fast fading channels}, url={http://dx.doi.org/10.1109/CTMC.1999.790226}, DOI={10.1109/CTMC.1999.790226}, abstractNote={Previously, the authors introduced a novel algorithm for long range prediction of fading channels. This algorithm finds the linear minimum mean squared error (MMSE) estimate of the future fading coefficients given a fixed number of previous observations. In this paper, we show that the superior performance of this algorithm is due to its lower sampling rate relative to the conventional (data rate) methods of fading prediction. We also enhance the algorithm by an adaptive prediction and tracking method that increases accuracy and maintains the robustness of long-term prediction as the physical channel parameters vary. Finally, we show that large improvements in the bit error rate (BER) are possible when the proposed prediction method is used. In particular, analysis of the channel inversion with threshold technique is presented to demonstrate that the BER can be reduced to the level of and beyond the additive white Gaussian noise (AWGN) channel.}, booktitle={1999 IEEE Communications Theory Mini-Conference (Cat. No.99EX352)}, author={Eyceoz, T. and Hu, S. and Duel-Hallen, A. and Hallen, H.}, year={1999}, pages={1–5} }
 @article{calderbank_duel-hallen_fishburn_rabinovich_1999, title={Interpolation by convolutional codes, overload distortion, and the erasure channel}, volume={45}, ISSN={["0018-9448"]}, DOI={10.1109/18.746774}, abstractNote={This paper investigates how closely randomly generated binary source sequences can be matched by convolutional code codewords. What distinguishes it from prior work is that a randomly chosen subsequence with density /spl lambda/ is to be matched as closely as possible. The so-called marked bits of the subsequence could indicate overload quantization points for a source sample generated from the tails of a probability distribution. They might also indicate bits where the initial estimate is considered reliable, as might happen in iterated decoding. The capacity of a convolutional code to interpolate the marked subsequence might be viewed as a measure of its ability to handle overload distortion. We analyze this capacity using a Markov chain whose states are sets of subsets of trellis vertices of the convolutional code. We investigate the effect of memory on the probability of perfect interpolation and calculate the residual rate on the unmarked bits of the binary source sequence. We relate our interpolation methodology to sequence-based methods of quantization and use it to analyze the performance of convolutional codes on the pure erasure channel.}, number={1}, journal={IEEE TRANSACTIONS ON INFORMATION THEORY}, author={Calderbank, AR and Duel-Hallen, A and Fishburn, PC and Rabinovich, A}, year={1999}, month={Jan}, pages={94–105} }
 @inproceedings{eyceoz_hu_duel-hallen_1999, title={Performance Analysis of Long Range Prediction for Fast Fading Channels}, volume={2}, booktitle={Proc. 33rd Annual Conference on Information Sciences and Systems CISS'99}, author={Eyceoz, T. and Hu, S. and Duel-Hallen, A.}, year={1999}, month={Mar}, pages={656–661} }
 @article{elezabi_duel-hallen_1997, title={A novel interleaving scheme for multiuser detection of coded CDMA systems}, number={6}, journal={TR (Center for Advanced Computing and Communication)}, author={Elezabi, A. and Duel-Hallen, A.}, year={1997} }
 @article{eyceoez_duel-hallen_1997, title={Simplified Block Adaptive Diversity Equalizer for Cellular Mobile Radio}, volume={1}, ISSN={["1558-2558"]}, DOI={10.1109/4234.552143}, abstractNote={We propose a reduced complexity antenna diversity combiner-equalizer receiver structure to combat multipath fading in cellular mobile radio (CMR) communications. The technique utilizes block adaptation based on interpolated channel estimates and linear or decision feedback equalization. The receiver offers complexity reduction relative to previously proposed block adaptation methods without sacrificing performance.}, number={1}, journal={IEEE COMMUNICATIONS LETTERS}, author={Eyceoez, Tugay and Duel-Hallen, Alexandra}, year={1997}, month={Jan}, pages={15–18} }
 @article{fulghum_molnar_duel-hallen_1997, title={The Jakes fading model incorporating angular spread}, number={7}, journal={TR (Center for Advanced Computing and Communication)}, author={Fulghum, T. L. and Molnar, K. J. and Duel-Hallen, A.}, year={1997} }
 @misc{townsend_punjabi_duel-hallen_alexander_1996, title={Apparatus and method for echo characterization of a communication channel}, volume={5,577,116}, number={1996 Nov. 19}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Townsend, K. and Punjabi, H. and Duel-Hallen, A. and Alexander, S. T.}, year={1996} }
 @inproceedings{duel-hallen_1992, place={Princeton, NJ, USA}, title={On suboptimum detection for asynchronous code-division multiple access channels}, booktitle={Proceedings of the Conference on Information Sciences and Systems}, author={Duel-Hallen, A.}, year={1992}, pages={838–838} }
 @inproceedings{duel-hallen_heegard_1987, place={USA}, title={Signal processing in digital recording: the delayed decision feedback sequence estimation algorithm}, volume={696}, booktitle={Proc. SPIE - Int. Soc. Opt. Eng. (USA)}, author={Duel-Hallen, A. and Heegard, C.}, year={1987}, pages={210–21} }