A Low Cost Direct Channel Feedback Method in OFDMA Systems
OFDMA框架下一种低代价直接信道信息反馈方法

A low cost, real-time CSI feedback method is proposed. The analog DownLink Channel State Information (DL-CSI) obtained at receivers is spreaded and then superimposed upon UpLink User Sequences (UL-US) before transmitting, thus avoiding DL-CSI from exclusive occupation of system resources. Using interference cancellation, iterative UL-US detection and DL-CSI estimation is carried out at base station. Due to spreading, DL-CSI can be accurately recovered even with little allocated energy. Simulations results demonstrate the practicability of the proposed method.