Spatial Modulation (SM) is a Multi-Input Multi-Output (MIMO) transmission technique where only one antenna transmits data in each transmission interval, leading to a reduction in the number of RF chains and transmission power. The application of SM in Massive MIMO systems relies on perfect channel estimation, which is a fundamental challenge in these systems. Differential Spatial Modulation (DSM) is a method proposed to avoid channel estimation challenges. However, the conventional square DSM cannot easily be applied to multi-user communication applications. In this paper, a novel Multi-User Differential Spatial Modulation (MU-DSM) transmission scheme is proposed for multi-user massive MIMO uplink communications. Moreover, for the proposed transmission scheme, a non-coherent MU-DSM detector is presented. As demonstrated in the analytical and simulation results, the proposed MU-DSM scheme performs very close to its coherent counterpart where perfect channel information is available.

空间调制（SM）是一种多输入多输出（MIMO）传输技术，其中每个传输间隔中只有一个天线传输数据，从而减少了RF链的数量和传输功率。SM在大规模MIMO系统中的应用依赖于完美的信道估计，这是这些系统中的一个基本挑战。差分空间调制（DSM）是一种为避免信道估计挑战而提出的方法。然而，常规的正方形DSM不能容易地应用于多用户通信应用。本文针对多用户大规模MIMO上行链路通信，提出了一种新颖的多用户差分空间调制（MU-DSM）传输方案。此外，对于所提出的传输方案，提出了一种非相干MU-DSM检测器。