波束成形在TD-LTE-A系统中的性能优化

TD-LTE系统中的波束成形（Beam Forming）会受到收、发天线不对称性的影响。TD-LTE-Advanced（TD-LTE-A）系统中使用上行多天线发送可以解决天线不对称性的问题，因此需要对其分析以优化Beam Forming的性能。通过对上行多天线的信道状态信息（CSI）做特征值（SVD）分解，指出了Beam Forming对下行信噪比（SNR）的改善。针对Beam Forming模式下SNR和链路质量指示（CQI）的差异，提出了一种优化链路自适应的方法。数值仿真验证了优化后的TD-LTE-A相比TD-LTE的Beam Forming吞吐率最大提高了24%，其结论对商用TD-LTE网升级到TD-LTE-A具有显著价值。

Performance optimization of beam forming in TD-LTE-A systems

Beam forming in TD-LTE systems is affected by the mis-match between receiver and transmitter antenna number.The antenna mis-match problem can be solved by uplink multiple antenna transmission in TD-LTE-Advanced(TD-LTE-A) systems,which shoud be analyzed so as to optimize the beam forming performance. By using singular value decomposition(SVD) for uplink multiple antenna channel state information(CSI),it points out that beam forming can improve downlink signal-to-noise ratio(SNR). According to the difference between SNR and channel quality indicator(CQI) when beam forming is used,an optimized link adaptation method is proposed.Simulations show the maximum 24% downlink throughput gain is improved by the optimized beam forming in TD-LTE-A systems in comparison with the TD-LTE systems. The conclusion has obvious value for the commercial network evolution from TD-LTE to TD-LTE-A.