Massive MIMO pre-coding algorithm based on truncated Kapteyn series expansion

In order to reduce the computational complexity of precoding in massive MIMO systems, we propose a Kapteyn-series based regularized zero-forcing (RZF) approach to approximate the matrix inversion. Numerical results show that, when signal to noise ratio (SNR) is low or the error of channel estimation is large, the series-expansion based RZF precoding performs the same as ordinary RZF approach, and in the case of the same truncation order, our proposed Kapteyn-series based approach performs better than the traditional Taylor-series approach.