采用Rao-Blackwellised粒子滤波的时变多用户检测  

Time-varying Multi-user Detection Based on Rao-Blackwellised Particle Filtering

作　　者：赵知劲[1,2] 胡波[1] 杨小牛[2] 

机构地区：[1]杭州电子科技大学通信工程学院,浙江杭州310018 [2]中国电子科技集团第36研究所通信信息控制和安全技术国家级重点实验室,浙江嘉兴314001

出　　处：《信号处理》2011年第9期1365-1369,共5页Journal of Signal Processing

摘　　要：传统多用户检测方法通常假定接收方已知活跃用户数,其一般为这个系统所能容纳的最大用户个数。在此前提下,传统多用户检测方法能够获得较好的性能。然而在实际多址移动通信系统中活跃用户个数及其参数往往都是时变的,因此传统多用户检测方法性能恶化。针对这个问题,本文首先采用随机集理论(Random Set Theory,RST)建立多用户动态模型,基于此模型将信道分解为离散部分和连续部分,并通过分析两者的关系得到它们的状态转移概率;然后提出了采用Rao-Blackwellised粒子滤波(RBPF)算法的时变多用户检测器,实现了活跃用户数目变化和信道幅度变化的跟踪及用户发送数据估计;最后给出了算法在抗噪声能力、抗远近效应和系统容量等方面的仿真结果。仿真结果表明本文算法性能明显优于传统多用户检测方法。Conventional multi-user detection methods generally assume that the number of active users is known at the receiver, which is usually considered to be the maximum number of users that the system can contain.Under this assumption,conventional methods for multi-user detection can achieve good performance.However,the number of active users as well as their parameters is usually unknown and time-varying in practical multi-access communication systems.As a result,the performance of conventional methods is deteriorated. In accordance with this problem,in this paper,a dynamic model of multi-user is established by using random set theory （RST）,after that the channel is decomposed into two parts,one is the discrete part and the other is the continuous part.Through analyzing the relationship between the two parts,the state transition probability is obtained.And then a time-varying multi-user detector based on Rao-Blackwellised particle filtering（RBPF） algorithm is proposed.So that the number of active users and the amplitude of channel can be sufficiently traced and the users＇ transmitted data are estimated.The performance in anti-noise,near-far resistance and system capacity of this algorithm is presented.Simulation results show that the performance of the proposed method is better than that of conventional methods.

关 键 词：多用户检测 时变 随机集 粒子滤波 

分 类 号：TN911.72[电子电信—通信与信息系统]