Asynchronous Cell-Free Massive MIMO-OFDM: Mixed Coherent and Non-Coherent Transmissions

作     者：Li, Guoyu Wu, Shaochuan You, Changsheng Zhang, Wenbin Shang, Guanyu 

作者机构：Harbin Inst Technol Sch Elect & Informat Engn Harbin 150080 Peoples R China Southern Univ Sci & Technol SUSTech Dept Elect & Electr Engn Shenzhen 518055 Peoples R China Harbin Inst Technol Innovat Photon & Imaging Ctr Sch Instrumentat Sci & Engn Harbin 150080 Peoples R China 

出 版 物：《IEEE COMMUNICATIONS LETTERS》 (IEEE Commun Lett)

年 卷 期：2025年第29卷第2期

页      面：363-367页

核心收录：

学科分类：0810[工学-信息与通信工程] 0808[工学-电气工程] 08[工学] 

基　　金：National Natural Science Foundation of China 

主　　题：OFDM Channel estimation Uplink Downlink Clustering algorithms Precoding Time-frequency analysis Symbols Vectors Central Processing Unit Cell-free massive MIMO mixed coherent and non-coherent transmissions asynchronous reception 

摘      要：In this letter, we analyze the performance of asynchronous cell-free multiple-input multiple-output orthogonal frequency division multiplexing (CF mMIMO-OFDM) system with mixed coherent and non-coherent transmission approaches. To this end, we first obtain the achievable downlink sum-rate for the mixed coherent and non-coherent transmissions, and then provide a closed-form expression for the case with the maximum ratio precoding. Subsequently, an efficient access point (AP) clustering algorithm is proposed to group APs into a set of coherent clusters. Numerical results demonstrate that the mixed coherent and non-coherent transmissions can effectively improve the sum-rate of CF mMIMO-OFDM systems under asynchronous reception.