This letter investigates the use of differential space-time block coding (DSTBC) to address antenna array calibration impairments at multi-antenna user equipment (UE) in the downlink (DL) of cell-free massive MIMO (CF-mMIMO) systems. We show that, by exploiting DSTBC, reliable DL communication can be achieved without explicit UE-side calibration or channel phase knowledge. Simulation results demonstrate that the proposed DSTBC-based transmission effectively mitigates the impact of antenna-dependent phase offsets, restoring near-coherent performance in CF-mMIMO networks.

翻译：本文研究了在无蜂窝大规模多输入多输出系统的下行链路中，利用差分空时分组码解决多天线用户设备侧天线阵列校准缺陷的问题。我们证明，通过采用差分空时分组码技术，无需显式的用户侧校准或信道相位信息即可实现可靠的下行通信。仿真结果表明，所提出的基于差分空时分组码的传输方案能有效抑制天线相关相位偏移的影响，使无蜂窝大规模多输入多输出网络恢复近乎相干传输的性能。