异构网络通过布设一些低功率的基站大幅提升频谱效率,同时也带来了严重的干扰,迫切需要一种多点协作传输方法避免干扰.针对此问题,提出了一种异构网络下基于空时分组码块对角化(space-time block coding-block diagonalization,STBC-BD)的多点协作传输方法.挑选符合协作传输条件的用户,改进用户的双流波束赋形矩阵,形成多用户双流协作传输;同时利用空时分组码对于用户的各层数据编码,提高接收信噪比;提出了一种基于干扰抵消(successive interference cancelation,SIC)的STBC-BD系统解码方法,进一步降低误码率.仿真结果表明,该算法在4×4天线配置情况下能够降低异构网络用户约3.5 d B误码率(BER);结合SIC的STBC-BD解码方法与传统最小均方误差(MMSE)解码方法相比误码率降低了约2 d B.
The shrinking of cell-size brings significant changes to the wireless uplink of densely small cells （DSCs）. A codebook design is proposed that utilizes the strong line of sight （LOS） chan- nel component existing in a DSC system for uplink of the DSC system. To further improve the uplink performance, the high-rank codebook is designed based on singular value decomposition （SVD） due to the unnecessary preservation of strict constant modulus in the DSC system. And according to the simulation result, the proposed codebook leads to significant sum-rate gain and appreciable block error rate （BLER） performance improvement in the DSC system.
