Robust Decentralized Coordinated Precoding in Multi-cell Coherent Joint Transmission Networks
Shaojun Wan, Xinyu Bian, Wenjie Wang, Tianqi Hou, Yong Zhou · 2024
Coherent joint transmission (CJT) is a promising technology to improve the spectral efficiency of multi-cell communication systems. In this paper, we investigate the transmit power minimization problem in multi-cell CJT networks. To realize the decentralized coordination that avoids the costly exchange of instantaneous channel state information, we leverage the deterministic equivalents for the approximation of inter-cell interference to decouple the overall precoding problem into independent sub-problems, which can be solved locally at each base station. In addition, to compensate the performance loss caused by the channel aging, we further propose a robust precoding scheme and develop an efficient solver based on the alternating direction method of multiplier. Extensive numerical results show that both the decentralized coordination and robust precoding design provide our proposed method with performance improvement.