Multiuser two-way relaying: detection and interference management strategies

• Published in: IEEE transactions on wireless communications Vol. 8; no. 8; pp. 4296 - 4305
• Main Authors: Min Chen, Yener, A.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.08.2009; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Applied sciences; Bidirectional control; Bit error rate; Broadcasting; Code Division Multiple Access; Decoding; Detection, estimation, filtering, equalization, prediction; Digital relays; Exact sciences and technology; Information, signal and communications theory; Interference; MMSE-multiuser detection; Multiaccess communication; Optimization; Peer to peer computing; Power control; Protocols; Receivers; Relay; Relay networks; Relaying; Signal and communications theory; Signal, noise; Studies; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Transmission and modulation (techniques and equipments); Two-way relaying; Multiuser detection; Performance evaluation; Two-way relaying; Multiple access; Relaying; Bidirectional link; Relay; Bit error rate; Wireless telecommunication; Updating; Iterative method; Algorithm; Optimization; Mean square error; Decision rule; MMSE-multiuser detection; Simulation; Power control; Code division multiple access; Broadcasting; Signal detection
• ISSN: 1536-1276; 1558-2248
• DOI: 10.1109/TWC.2009.081165

We consider a multiuser two-way relay network where multiple pairs of users communicate with their preassigned partners, using a common intermediate relay node, in a two-phase communication scenario employing code division multiple access (CDMA). By taking advantage of the bidirectional communication structure, we first propose that each pair of partners share a common spreading signature and design a jointly demodulate-and-XOR forward (JD-XOR-F) relaying scheme, where all users transmit to the relay simultaneously followed by the relay broadcasting an estimate of the XORed symbol for each user pair. We derive the decision rules and the corresponding bit error rates (BERs) at the relay and at the users' receivers. We then investigate the joint power control and receiver optimization problem for each phase for this multiuser two-way relay network with JD-XOR-F relaying. We solve each optimization problem by constructing the iterative power control and receiver updates that converge to the corresponding unique optimum. Simulation results are presented to demonstrate the performance of the proposed multiuser two-way JD-XOR-F relaying scheme in conjunction with the joint power control and receiver optimization algorithms. Specifically, we observe significant power savings and user capacity improvement with the proposed communication scheme as compared to the designs with a "one-way" communication perspective.