Joint Tx/Rx signal processing for uplink distributed antenna network using single-carrier MU-MIMO

A combination of distributed antenna network (DAN), where a number of antennas are spatially distributed within a macro cell, and multi-user (MU) multiple-input multiple-output (MIMO) can achieve high total throughput. Recently, we proposed a minimum mean square error based joint transmit and receive linear filtering (joint Tx/Rx MMSE filtering) for single-carrier (SC)-MU-MIMO uplink. Joint Tx/Rx MMSE filtering transforms the MIMO channel between each user equipment (UE) and base station (BS) to multiple eigenmodes, and applies MMSE based power allocation (PA). MMSE-PA achieves good bit error rate (BER) performance by allocating much power to the eigenmodes having low channel gains (or eigenvalues). However, in DAN, large gaps exist among eigenvalues since the average received signal power of DA is different from each other, and this leads to a significant throughput degradation. Therefore, PA should be designed from the view point of throughput (i.e., Shannon's channel capacity). This paper proposes a joint Tx/Rx WF-MMSE filtering for uplink DAN using SC-MU-MIMO. Water-filling (WF)-PA which maximizes the throughput and MMSE-PA are applied in eigenmode-domain and in frequency-domain, respectively. Numerical results show that proposed filtering achieves better throughput performance than the previously proposed joint Tx/Rx MMSE filtering.