Experiments on space diversity effect in MIMO channel transmission with maximum data rate of 1 Gbps in downlink OFDM radio access

Abstract

AbstractThis paper presents experimental results on the space diversity effect in MIMO multiplexing/diversity with the target data rate up to 1 Gbps using OFDM radio access based on laboratory and field experiments including realistic impairments using the implemented MIMO transceivers with the maximum of four transmitter/receiver branches. The experimental results using multipath fading simulators show that at the frequency efficiency of less than approximately 2 bits/second/Hz, MIMO diversity using the space‐time block code (STBC) increases the measured throughput compared to MIMO multiplexing owing to the high transmission space diversity effect. At a higher frequency efficiency than approximately 2‐‐3 bits/second/Hz, however, MIMO multiplexing exhibits performance superior to that of MIMO diversity since the impairments using higher data modulation and a higher channel coding rate in MIMO diversity overcomes the space diversity effect. The results also show that the receiver space diversity effect is very effective in MIMO multiplexing for maximum likelihood detection employing QR‐decomposition and the M‐algorithm (QRM‐MLD) signal detection. Finally, we show that the real‐time throughput of 500 Mbps and 1 Gbps in a 100‐MHz transmission bandwidth is achieved at the average received Eb/N0 per receiver antenna of approximately 8.0 and 14.0 dB using 16QAM modulation and Turbo coding with the coding rate of 1/2 and 8/9 respectively in 4‐by‐4 MIMO multiplexing in a real propagation environment. Copyright © 2006 AEIT.