A new optimal MUD algorithm based on searching in the local space of sub-optimal MMSE solutions for DS-UWB communication systems
A new optimal MUD algorithm based on searching in the local space of sub-optimal MMSE solutions for DS-UWB communication systems
复制标题
DS-UWB通信系统基于次优MMSE解局部空间搜索的新型最优MUD算法
DOI：
10.1080/02533839.2012.655538
复制
发表时间：
2012-04-01
影响因子：
1.1
通讯作者：
Wu, Zhilu
中科院分区：
文献类型：
--
作者：
Yin, Zhendong;Zong, Zhiyuan;Wu, Zhilu
在本文中，我们研究了多接入（MA）直接序列超宽带（DS-UWB）系统中应用的多用户检测（MUD）技术。分析了几种典型的MUD算法，提出了一种基于次优最小均方误差(MMSE)解的局部空间搜索的近似最优MUD算法。该算法将MMSE的次优解作为局部搜索的初始值，然后通过欧氏距离构造该次优解的局部解空间。在这个空间内，搜索经典最优MUD算法（OMUD）的一些可能的解，并选择其中最优的一个作为这种新的最优MUD算法的解。理论分析和仿真结果表明，该算法的误码率性能和抗近远效应能力明显优于MMSE和自适应MMSE检测，与OMUD非常接近。此外，它的时间复杂度比OMUD低得多。与自适应MMSE相比，该算法在选择合适的自适应MMSE参数方面没有困难。除此之外，我们还研究了这种新算法在抑制数字窄带干扰（NBI）问题中的应用。可以明显看出，该近似最优算法在强NBI环境下具有完美的性能，并且与相同条件下的经典OMUD算法吻合。
In this paper, we have studied the multiuser detection (MUD) technology applied in multiaccess (MA) direct sequence ultrawideband (DS-UWB) systems. Some typical MUD algorithms were analyzed and a new approximate optimal MUD algorithm based on searching in the local space of suboptimal minimum mean-squared error (MMSE) solution was proposed. In this new algorithm, the suboptimal solution of MMSE is considered as the initial value for the local search, and then a local solution space of this suboptimal solution is constructed by Euclidean distance. Within this space, some likely solutions for the classical optimal MUD algorithm (OMUD) are searched and the optimal one of them is chosen as the solution of this new optimal MUD algorithm. Theoretical analysis and simulation results indicate that, the BER performance and the Near-far Effect resistant ability of this proposed algorithm are much better than those of MMSE and adaptive MMSE detections, which are very close to those of OMUD. Furthermore, its time complexity is much lower than OMUD's. Compared to adaptive MMSE, this algorithm has no difficulty in choosing the suitable parameters for adaptive MMSE. Besides these, we examine the application of this new algorithm to the problem of suppressing the digital narrowband interference (NBI). It is clearly seen that this approximate optimal algorithm has perfect performance under strong NBI circumstance and coincides with the classical OMUD algorithm bound in the same condition.