Title :
MIMO Relaying With Linear Processing for Multiuser Transmission in Fixed Relay Networks
Author :
Chae, Chan-Byoung ; Taiwen Tang ; Heath, Robert W. ; Cho, Sunghyun
Author_Institution :
Univ. of Texas at Austin, Austin
Abstract :
In this paper, a novel relaying strategy that uses multiple-input multiple-output (MIMO) fixed relays with linear processing to support multiuser transmission in cellular networks is proposed. The fixed relay processes the received signal with linear operations and forwards the processed signal to multiple users creating a multiuser MIMO relay. This paper proposes upper and lower bounds on the achievable sum rate for this architecture assuming zero-forcing dirty paper coding at the base station, neglecting the direct links from the base station to the users, and with certain structure in the relay. These bounds are used to motivate an implementable multiuser precoding strategy that combines Tomlinson-Harashima precoding at the base station and linear signal processing at the relay, adaptive stream selection, and QAM modulation. Reduced complexity algorithms based on the sum rate lower bounds are used to select a subset of users. We compare the sum rates achieved by the proposed system architecture and algorithms with the sum rate upper bound and the sum rate achieved by the decode-and-forward relaying.
Keywords :
MIMO communication; broadcast channels; cellular radio; computational complexity; multiuser channels; precoding; quadrature amplitude modulation; radio links; signal processing; MIMO relaying; QAM modulation; Tomlinson-Harashima precoding; adaptive stream selection; base station; broadcast channels; cellular networks; fixed relay networks; linear signal processing; lower bounds; multiple-input multiple-output fixed relays; multiuser precoding strategy; multiuser transmission; reduced complexity algorithms; upper bounds; Adaptive signal processing; Base stations; Decoding; Land mobile radio cellular systems; MIMO; Quadrature amplitude modulation; Relays; Signal processing; Signal processing algorithms; Upper bound; Broadcast channels (BC); multiple-input multiple-output (MIMO) systems; multiuser channels; relays;
Journal_Title :
Signal Processing, IEEE Transactions on
DOI :
10.1109/TSP.2007.907821