基于半正定松弛的MIMO系统下行链路预编码方案

摘要

The way of controlling transmit power, in a precoding method based on maximal Signal-to-Leakage-plus-Noise Ratio (SLNR) for multiuser MIMO downlinks, is not efficient to ensure each user's available SLNR value, so a precoding scheme pursuing design goal that minimizes total transmit power under each user's SLNR constraint is proposed. The goal issues can be successfully solved by using SemiDefinite Relaxation (SDR) techniques, and power constraint condition added in goal issues can efficiently reduce total transmit power of the base station. Simulation results show that the proposed scheme that satisfies large SLNR thresholds, has better Bit Error Rate (BER) and lower total transmit power than the maximal SLNR based precoding method. Moreover, the higher the system Signal-to-Noise Ratio (SNR), the lower the total transmit power of the scheme.%多用户多输入多输出系统下行链路中,信漏噪比最大化的预编码方法的发射功率控制方式并不能有效保证用户可达的信漏噪比,该文提出追求信漏噪比约束下最小化发射总功率的预编码器设计方案.利用半正定松弛的方法对目标问题可以进行有效地求解,并且在设计目标中增加功率约束条件,能有效降低基站的发射总功率.仿真结果显示相比于信漏噪比最大化方法,该文提出的方案在满足较大的信漏噪比门限时具有更好的系统误码性能和更低的发射总功率,并且随着信噪比的增加,其发射总功率不断降低.