TDD大规模MIMO系统中两种新的下行预编码方案

针对时分双工大规模MIMO系统，该文提出两种新的下行链路预编码方案，即新最大比合并(NMRC)和新迫零(NZF)方案，通过理论分析得到两种新预编码方案下目标用户和非目标用户的下行链路信干噪比和频谱效率的表达式，并与传统的迫零(ZF)和最大比合并(MRC)预编码的下行链路信干噪比、频谱效率和误码率性能进行比较。仿真结果表明，所提出的NMRC和NZF预编码与传统的MRC和ZF预编码相比，在不增加运算复杂度的前提下可以获得更好的性能，而且新的预编码方案在提高目标用户性能的同时，对其他非目标用户的性能也有一定的改善。

Two Novel Downlink Precoding Schemes for TDD Massive MIMO Systems

For time-division duplex massive MIMO systems, two new downlink precoding schemes are proposed, namely New Maximum Ratio Combining (NMRC) and New Zero-Forcing (NZF) scheme. Through theoretical analysis, the expressions of downlink signal to interference plus noise ratio and spectral efficiency of target users and non-target users under two new precoding schemes are obtained, and compared with traditional Zero-Forcing (ZF) and Maximum Ratio Combining (MRC) Precoding schemes for downlink signal to interference plus noise ratio, spectrum efficiency and bit error rate performance. The simulation results show that the proposed NMRC and NZF precoding can achieve better performance without increasing the computational complexity compared with the traditional MRC and ZF precoding. Moreover, the new precoding schemes improve the performance of target users while improving the performance of other non-target users.