Hybrid Analog and Digital Precoding Algorithm Based on Channel Reciprocity for Multiuser Millimeter Wave MIMO Systems

This paper aims at multiuser millimeter wave (mmWave) MIMO system, first proposes an analog receive scheme for mmWave system with split subarray MIMO hybrid analog and digital precoding architecture. Designing hybrid analog and digital precoders with the target of maximize the sum rate is a triple joint optimization problem, which can be divided into analog part and digital part. Based on the channel reciprocity, this paper further proposes a hybrid analog and digital precoding algorithm. The algorithm obtains analog combining vectors by maximizing the reception SINR of each downlink user, and achieves analog precoding vectors by maximizing the reception SINR of each uplink antenna arrays. After the analog part is optimized, transmitter’s digital precoder is designed to eliminate the interference between multiple users’ data streams. Numerical results show that the proposed algorithm convergences fast, and can achieve performance near the optimal purely digital precoding algorithm.