Realizing high-accuracy transmission in high-rate data broadcasting networks with heterogeneous users via cooperative communication

This paper considers a broadcasting network in which multiple single-antenna (weak) and multiantenna (strong) users are receiving simultaneously spatial-multiplexed data streams from the multiantenna base station (BS). In order to improve the received data quality for the single-antenna users while preserving the transmission rates of the multiantenna users, we propose user cooperation schemes without the employment of space-time codes or retransmission from the BS which reduce the data rates and the spectral efficiency. Three cooperation schemes among single-antenna users, namely, decode-andforward (DF), amplify-and-forward (AF), and hybrid cooperation, are examined and compared. Simulation results demonstrate that single-antenna users through cooperation can achieve comparable or superior error-rate performance as compared with noncooperative multiantenna users. Various configurations of the proposed cooperation schemes are studied to show the tradeoff in terms of cooperation overhead, receiver complexity, and system performance. The acquisition of the channel information and the effect of channel estimation errors on the system performance are also investigated for practical implementation of the proposed schemes. The proposed schemes are capable of avoiding modification to the multipleinput multiple-output (MIMO) transceivers, and are readily applicable to existing MIMO broadcasting networks. (C) 2013 Elsevier Inc. All rights reserved.