协同分布式天线系统中的自适应比特分配算法

Adaptive bit partition algorithm in cooperative distributed antenna systems

针对协同分布式天线系统,提出了一种新的有限反馈比特分配算法,以最小化信道量化误差造成的速率损失.在多用户协同分布式天线系统中,存在两种干扰:本小区内的多用户干扰和来自周围小区的小区间干扰.为了抑制这两种干扰,该文使用随机矢量量化的码本,分别量化来自本小区和周围干扰小区的信道状态信息.在用户总反馈开销固定时,采用最优化方法得出为本小区和周围小区分配反馈比特数的最优解.仿真结果表明,该算法与平均比特分配算法相比有效地提升了用户平均传输速率.

This paper proposes a new limited feedback bit partition algorithm to mimmize the rate loss caused by the channel quantization error, based on the cooperative distributed antenna system （DAS）. There are two kinds of interferences in multi-user cooperative DAS： multi-user interference （MUI） within the local cell and inter-cell interference （ICI） from adjacent cells. To suppress these two kinds of interferences, this paper uses the random vector quantization （RVQ） codebook to separately quantize the channel state information （CSI） from the local cell and adjacent cells. Under the condition that uses＇ total feedback overhead is fixed, we use a two-step optimization method to obtain the optimal solution of the feedback bit number allocated to local and adjacent cells. Simulation results show that the proposed algorithm effectively increases the average transmission rate compared with the equal-bit partition algorithm.