Multiuser differential transmission scheme for massive MIMO systems

Channel estimation is a big challenge in multiuser massive multiple-input multiple-output systems. A novel multiuser differential transmission scheme for uplink transmission with a large antenna array at the base station (BS) is proposed. In the proposed scheme, a block-by-block differential encoder is employed at each user, while simple symbol-wise differential decoder is used at the BS to recover the information symbols without any knowledge of the channel state information (CSI). The performance of the proposed scheme when the number of BS antennas grows large is analysed. Both analytical and numerical results show that the proposed differential transmission scheme is able to achieve almost the same bit-to-error rate performance as the coherent maximum ratio combining receiver with perfect CSI in the high signal-to-noise ratio region.