Performance analysis of delayed limited feedback based on per-cell codebook in CoMP systems

Per-cell codebook based limited feedback technique in the coordinated multi-point transmission (CoMP) system has received more and more attention because of its flexibility and scalability. In practical CoMP systems, quantized channel state information (CSI) is subject to a feedback delay due to signal processing at the receiver, finite bandwidth of feedback links, and finite capacity of backhaul links. In this paper, we study the effect of different codeword selection schemes based on per-cell codebook on data rate in CoMP systems. The impact of CSI feedback delay is considered by using Gauss-Markov temporal correlation channel model. We derive the theoretical upper bounds of data rate for two codeword selection schemes, joint codeword selection (JCS) and independent codeword selection (ICS) respectively. Simulation results show that the practical data rate is close to the theoretical data rate upper bound both for JCS and ICS, which has validated the availability of the theoretical data rate upper bounds.