摘要:
通过引入满速率空时分组码方案, 该文给出一种满速率空时分组编码CDMA系统模型, 并针对现有空时编码CDMA系统过高的译码复杂度, 提出一种低复杂度的多用户接收方案。该方案在通过类似多用户检测方法有效抑制多用户干扰后, 充分利用空时分组码的复正交性来简化原有方案高译码复杂度。与原有指数性译码复杂度相比, 该方案有着线性复杂度, 而且与满分集空时分组编码CDMA系统相比, 可实现满速率、低复杂度和部分分集, 有着相对多的空间冗余信息, 从而级联信道编码后可有效弥补部分分集所带来的性能损失。仿真结果表明在相同系统容量和级联码的情况下, 所给系统比相应的满分集空时编码CDMA系统有着低的误比特率。
Abstract:
By introducing full-rate Space-Time Block Coding (STBC) scheme, a Full-rate Space-Time Block Coded CDMA (FSTBC-CDMA) system model is given in this paper. Considering that existing space-time coded CDMA system has high decoding complexity, a low-complexity multiuser receiver scheme is also proposed. The scheme can make full use of the complex orthogonality of STBC to simply the high decoding complexity of the existing scheme after multiuser detection method like is employed to suppress multiuser interference effectively; it has linear decoding complexity when compared with existing scheme (it has exponential decoding complexity). Moreover, compared with full-diversity space-time block coded CDMA, the FSTBC-CDMA system can implement full rate, low complexity and partial diversity, has more spatial redundant information. Thus the concatenation of channel coding can effectively compensate for the performance loss due to partial diversity. Simulation results also show that on the condition of same system throughput and concatenation of channel code, the proposed FSTBC-CDMA system has lower Bit Error Rate (BER) than those low-rate and full-diversity space-time block coded CDMA system.