Achievable Rate Analysis of Hybrid Massive MIMO Uplink with Imperfect Phase Shifters

In a multiuser massive multiple-input multipleoutput (MIMO) system, hybrid analog-and-digital structure is widely applied due to the high cost of deploying a large number of radio-frequency (RF) chains to drive the large antenna array. Phase shifter network is a common way of accomplishing the analog component. However, phase shifters impaired by hardware constrains can seriously degrade the performance of the system. This paper investigates the influence of imperfect phase shifters on the uplink achievable rate of the system with fullyconnected and sub-connected architectures. We derive a tractable expression for the uplink achievable sum rate. The proposed studies show that massive antennas are able to compensate for the performance degradation caused by imperfect phase shifters in the hybrid massive MIMO system. Our analytical results are verified by extensive simulations.