Power allocation based on SLNR precoding in multi-cell MU-MIMO systems

In order to eliminate or reduce inter-user interference (IUI) and inter-cell interference (ICI), a power allocation algorithm based on leakage signal-to-noise ratio (SLNR) precoding is proposed for multi-cell multi-user multiple-input multiple-output (MU-MIMO) downlink system. The optimization problem can be divided into two subproblems: precoding design and power allocation. Firstly, the optimal precoding matrix can be obtained according to the maximization of SLNR criterion. Then Lagrange multiplier algorithm is used to find the optimal power allocation matrix, so as to improve the energy efficiency of the system. Simulation results show that compared with zero-forcing (ZF) combined with equal power allocation algorithm and block diagonal (BD) combined with water filling algorithm, the proposed algorithm can reduce the bit error rate (BER) performance and achieve higher energy efficiency.