Uplink capacity of a single-carrier multi-user MIMO multiplexing in a frequency-selective channel

Multi-user single-carrier (SC) MIMO multiplexing has been attracting a lot of attention due to its low peak-to-average power ratio (PAPR). As the transmission rate increases, the channel becomes frequency-selective and the bit error rate (BER) performance degrades significantly due to intersymbol interference (ISI). Frequency-domain equalization (FDE) provides a good BER performance since the frequency diversity gain can be obtained. In this paper, we evaluate, by computer simulation, the uplink capacity of multi-user SCMIMO multiplexing using FDE in a frequency-selective fading channel. Zero-forcing detection (ZFD) and minimum mean square error detection (MMSED) are considered. The uplink capacity is found from the complimentary cumulative distribution function (CCDF) of the local average BER, obtained by computer simulation. It is shown that larger uplink capacity can be achieved in a frequency-selective fading channel rather than in a frequency-nonselective fading channel and that almost the same capacity is obtained by ZFD and MMSED. It is also shown that ZFD and MMSED can provide almost 1.3 times larger uplink capacity than MMSEFDE+antenna diversity reception using 8-element receive antenna array.