Analysis of maximal-ratio transmit and combining spatial diversity

Abstract

Spatial diversity is still remaining as a powerful means to improve the transmission performance in a multipath fading environment. Various spatial diversity schemes have been proposed such as maximal-ratio transmit and combining (MRTC), selective MRTC, and space-time block coded transmit diversity (STBC-TD). In this paper, we derive a closed form expression for the received signal-to-noise ratio (SNR) achievable with MRTC for the case of base station (BS) having an arbitrary number of antennas and user-equipment (UE) having 2 antennas. Using the derived SNR expression, the average bit error rate (BER) performance of quaternary phase shift keying (QPSK) transmission in a Rayleigh fading environment is numerically evaluated. It is shown that MRTC provides the BER performance superior to STBC-TD and selective MRTC.

Gain of Spatial Diversity with Conjoint Signals in Arbitrarily Correlated Rayleigh Fading Channels

“…Receive diversity approaches are recognized to increase numerous figures of merit in wireless communications systems by providing redundant signals that can be combined to achieve a better quality of service (QoS) [1][2][3][4][5][6][7][8]. However, space restrictions, e.g., in mobile handsets make it difficult to receive uncorrelated signals, hence the need for decorrelation [3,[9][10][11].…”

Zero-forcing based multi-user MIMO coordinated with user-wise joint transmit-receive diversity

“…In this paper, we extend our previous study and propose user-wise joint transmit-receive diversity (JTRD) for ZF-based multi-user MIMO. JTRD was originally studied in [7] as single-user MIMO spatial diversity. Two types of user-wise JTRD are considered and the design of ZF precoder/postcoder, which takes into account the role of JTRD, is presented.…”

Analysis of 2-user ZF coordinated with user-wise MRTC diversity

“…Inspired by the above ZF based multi-user coordinated transmit-receive beamforming, assuming time division duplex (TDD), we apply the maximal-ratio transmitting and combining (MRTC) diversity [2,6,7] to the user transceiver and study downlink and uplink multi-user ZF coordinated with user-wise MRTC diversity. The optimal multi-user coordinated transmit-receive beamforming requires computationally expensive iterative algorithms to determine the beamforming at BS and user sides [3,4,5].…”