Distributed Precoder Based on Weighted MMSE With Low Complexity for Massive MIMO Systems

The weighted sum mean squared error minimization (WMMSE) algorithm has gained widespread adoption owing to its superior performance. In this letter, we propose a novel low-complexity distributed WMMSE (LCD-WMMSE) algorithm, which is implemented over a decentralized architecture based on ring topology. Although each distributed unit (DU) in LCD-WMMSE works only with the local channel state information (CSI), LCD-WMMSE algorithm is still able to approach the performance of traditional WMMSE. Moreover, we show that LCD-WMMSE is also scalable since its required interconnection bandwidth is independent of the number of transmitter antennas, making it promising to various scenarios of massive MIMO. Simulation results validate that the proposed LCD-WMMSE algorithm not only achieves the low complexity cost in a distributed manner but also exhibits negligible performance loss.