基于HPA非线性的大规模MIMO预编码算法

Linear Precoding in Massive MIMO Based on Nonlinear High-power Amplifier

大规模MIMO具有较高的能量效率和频谱利用率等优点,但由于廉价的硬件使用也会带来一些问题,比如高功率放大器非线性等。当高功率放大器工作在非线性区域时,放大后信号的幅度和相位都会产生误差,从而使得用户接收到的信号与期望信号产生误差,降低了系统的性能。研究了当高功率放大器非线性时,传统预编码算法的不足之处。然后,根据传统算法的不足与非线性的高功率放大器对信号的影响,提出一种改进的预编码算法。通过仿真结果可以看出,该算法相对块对角化预编码算法和迫零预编码算法在误码率和容量性能上有着显著提高,尤其是在高信噪比的场景下优势更佳。因此可以得出结论,该算法能够降低高功率放大器非线性对系统性能的影响。

Large scale MIMO has the advantages of high energy efficiency and spectrum utilization,but it also brings some problems be- cause of cheap hardware use, such as high power amplifier nonlinearity,etc.. When the high power amplifier in the nonlinear regime, the amplitude and phase of amplified signal will produce error, thereby leading to the errors of signal and the desired signal received by users and reduce the performance of the system. The deficiency of the traditional precoding algorithm is studied when the high power amplifier is nonlinear. An improved pre-coding algorithm is presented according to the impact of traditional algorithm and nonlinear high power amplifier on the signal. The simulation results show that the algorithm is improved significantly in bit error rate and capacity performance compared with block of diagonalization pre-coding algorithm and forced zero pre-coding algorithm, especially better in the scene of high signal to noise ratio. So it is concluded the algorithm is able to reduce the influence of nonlinearity of high power amplifier on the per- formance of the system.