最小尺度过饱和小波包分多址通信及其多用户检测

The lowest scale over-saturated wavelet packet division multiple access communication and its multi-user detection

为提高无线通信系统的容量,引入过饱和小波包分多址(wavelet packet division multiple access,WPDMA)通信.提出一种最小尺度过饱和小波包分多址地址码集,该地址码集选取最小尺度的小波包基函数作为过饱和地址码,也就是选取小波包树型结构中尽量靠近根节点的地址码作为过饱和地址码.利用小波包整齐的树型结构,将针对树型结构的低复杂度的最优检测算法作为过饱和小波包分多址系统的多用户检测方法.最小尺度过饱和多址系统可以提供比正交多址系统更高的容量,而在AWGN信道和单径Rayleigh衰落信道下的仿真都表明,最小尺度过饱和多址系统的性能仅稍差于正交多址系统,性能可以接受.针对树型结构的低复杂度最优检测算法使过饱和小波包分多址检测的复杂度从用户数的指数次方降为低阶多项式次方.

The Over-saturated Wavelet Packet Division Multiple Access （OWPDMA） is introduced to improve the capacity of wireless communication system. The lowest scale OWPDMA code set is presented, in which wavelet packet basis functions with the lower scales, i.e. codes on the nodes closing to the root in the tree,are selected as OWPDMA over-saturated codes. The low complexity optimal joint detection for tree-structured multiple access system is used as its multi-user detector （MUD）. Computer simulation results in AWGN channel and single path Rayleigh fading channel demonstrate that the lowest scale OWPDMA code set provides larger capacity than orthogonal code set does, and has the acceptable performance weakly inferior to that of orthogonal code set. Its MUD method reduces the complexity from exponential to low-order-polynomial in the number of users.