IEEE Communications Letters
Ergodic Secrecy Sum-Rate for Downlink Multiuser MIMO Systems With Limited CSI Feedback
Na Li, Xiaofeng Tao, Jin Xu
Abstract
This paper investigates the ergodic secrecy sum-rate for the downlink multiuser MIMO system with independent confidential messages, each of which is intended for one of the users and should keep secret from others. We adopt zero-forcing beamforming with limited channel state information (CSI) feedback at the transmitter, and derive the closed-form expression for the ergodic secrecy sum-rate. Moreover, we analyze some of its asymptotic characteristics, which provide guidance on secure transmission design. Finally, all theoretical results are validated by numerical simulations.