Joint Source-Channel Coding For Band-Limited Backhauls In Coordinated Multi-Point Systems

Coordinated multi-point (CoMP) transmission has been considered in the 3GPP long-term evolution advanced standard and beyond networks to improve the system throughput and coverage, particularly for cell-edge users. However, in practice the global channel state information (CSI) required by the coordinated points is usually transmitted by the band-limited backhauls, which degrades the performance of CoMP due to the erroneous backhaul transmission via the insufficient bandwidth. To address this problem, the authors propose a joint source-channel coding scheme for the backhaul transmission. They choose wavelet transform to compress the source CSI, and furthermore use irregular low-density parity-check codes to realise unequal error protection. They theoretically analyse how the joint coding affects the performance of CoMP. A trade-off between the compression ratio and channel coding gain is given. The numerical results verify that the proposed scheme can improve the performance of CoMP with band-limited backhauls.