Selective MIMO diversity with subcarrier-wise UE antenna identification/selection

Abstract

Antenna diversity is a powerful means to improve the bit error rate (BER) performance in wireless communication systems. In this paper, we propose selective multi-input multi-output (MIMO) diversity with subcarrier-wise user equipment (UE) antenna identification/selection in a doubly-selective fading channel. Pilot-aided channel estimation (PACE) is used for identifying/selecting the best UE antenna prior to data transmission and decision-feedback channel estimation (DFCE) is used to update the channel state information (CSI). It is confirmed by computer simulation that the proposed selective MIMO diversity provides the improved BER performance compared to MISO/SIMO diversity in low and high mobility environments.

Analysis of maximal-ratio transmit and combining spatial diversity

“…STBC-TD employs MRT (downlink)/MRC (uplink) [5]. Selective MRTC selects the best UE antenna while BS uses all antennas for MRT (downlink)/MRC (uplink) [6].…”

“…So far, various diversity schemes have been proposed, such as maximal-ratio combining (MRC) [1], selection combining (SC) [1], and maximal-ratio transmission (MRT) [2], and maximal-ratio transmit and combining (MRTC) [3,4]. The authors proposed space-time block-coded transmit diversity (STBC-TD) [5] which employs MRT and MRC at base station (BS) for downlink and uplink, respectively, and recently proposed selective multiinput multi-output (MIMO) diversity which selects the best UE antenna for MRT and MRC at BS for downlink and uplink, respectively [6] (called selective MRTC in this paper). It should be noted that, for the single-carrier uplink transmission, MRC needs to be replaced by the minimum mean square error combining (MMSEC) [7] since MRC emphasizes the inter-symbol interference (ISI).…”