基站协作系统中基于GAMP算法的RZFBF预编码实现
The Realization of RZFBF Pre-coding Based on GAMP Algorithm for Base Station Cooperation System

基站协作系统中，基于正则化迫零波束赋形(Regularized Zero Forcing Beam-Forming, RZFBF)的集中式协作预编码能够达到与脏纸编码近似的系统容量性能，然而随着协作基站数目的增多，集中式协作预编码对回程容量的要求变得极高.针对该问题，提出了基于广义近似消息传递（generalized approximate message passing,GAMP)的分布式预编码符号设计方案，通过相邻基站间的信息交互将全局计算开销分解成许多小的计算任务，极大的降低了系统对于回程容量的要求。仿真结果表明，所提算法能够以较低的计算复杂度获得近似于集中式RZFBF预编码算法所能达到的系统吞吐量。
In the base station cooperation system, the centralized cooperative pre-coding based on regularized zero-forcing beam-forming (RZFBF) could obtain a similar capacity performance to that of dirty-paper coding. However, with the number of cooperative base station increasing, the centralized cooperative pre-coding had a quite high requirement for the backhaul capacity. In order to solve this problem, a distributed transmitted signal design scheme based on generalized approximate message passing (GAMP) algorithm was proposed. The scheme decomposed the overall compucentralized RZFBF pre-coding problem into a problem of signal estimation by constructing a virtual linear communication system, and decomposes the overall computational cost into many smaller computation tasks by exchanging information between adjacent base stations, which greatly reduced the requirement of backhaul capacity. Simulation results showed that the proposed algorithm could achieve approximate system tjroughput with the centralized cooperative RZFBF pre-coding at a lower computational complexity.