南京大学学报(自然科学版) ›› 2010, Vol. 46 ›› Issue (6): 713718.
• • 上一篇
王杰令 1 ** , 杨 宏 1, 2 , 易克初 1 , 刘祖军 1
Wang J ie-Ling 1 , Yang H ong 1, 2 , Yi K e-Chu 1 , Liu Zu-J un 1
摘要: 在基于 Walsh 函数扩频的全速率码分复用( CDM) 系统中, 提出一种新颖的多符号联合盲均衡算法. 对于循环平稳信号, 可根据其二阶统计特性进行信道的盲估计, 然而这必须以降低系统的传输
速率为代价. CDM 信号的二阶统计相关序列由于多址干扰(MAI) 的影响, 不具有循环平稳性, 但是联合处理多个相互独立的码分复用符号, 通过对多个符号的联合统计可以消除二阶统计量中 MAI 的影响.
接收机采用匹配滤波器进行初步的解扩解调, 并基于初始解调结果构造 CDM 信号, 将该 CDM 信号以多个符号为单位与接收信号求互相关序列, 从中提取信道信息进行信道盲估计并且均衡. 在航空信道模
型中的- En-Route 场景下对新算法进行了 Monte Carlo 仿真, 实验结果表明当信噪比大于 6dB 后, 新算法可以取得良好的抗多径衰落性能.
[ 1 ] Proakis J G. Digital communications. New York: McGraw-Hill, 1989. [ 2 ] Durgin G D, Rappaport T S. Theory of multipath shape factors for small -scale fading wireless channels. IEEE Transactions on Antennas and Propagation, 2000, 48(5): 682~ 693. [ 3 ] Li T, Mow W H, Siu M. Joint erasure marking and list Viterbi algorithm for decoding in unknown non-gaussian noise. IEEE Transactions on Wireless Communications, 2008, 7 ( 3): 787~ 792. [ 4 ] Godard D N. Self?recovering equalization and carrier tracking in two -dimensional data communication systems. IEEE T ransactions on Communications, 1980, 28( 12) : 1867~ 1875. [ 5 ] Naveed A, Qureshi I M , Hussain A, et al. Blind equalisation of communication channels for equal energy sources: energy matching approach. Electronics Letters, 2006, 42 ( 4): 247~ 248. [ 6 ] Pinchas M , Bobrovsky B Z. A novel HOS approach for blind channel equalization. IEEE T ransactions on Wireless Communications, 2007, 6(3): 875~ 886. [ 7 ] Giannakis G B. Filterbanks for blind channel identification and equalization. IEEE Signal Processing Letters, 1997, 4(6): 184~ 187. [ 8 ] Abreu E, M itra S K, M archesani R. Nonminimum phase channel equalization using noncausal filters. IEEE Transactions on Signal Processing, 1997, 45( 1) : 1~ 13. [ 9 ] Vorobyov S A. Robust CDMA multiuser detec tors: probability-constrained versus the worstcase -based design. IEEE Signal Processing Letters, 2008, 15( 4) : 273~ 276. [ 10] Zhao S, Fu H L. An LSCM beam?forming algorithm in smart antenna MC?CDM A system. Journal of Nanjing University ( Natural Sciences) , 2005, 41(6): 675~ 679. ( 赵夙, 傅洪 亮. 一种智能天线 MC?CDMA 系统中的最小二乘恒模波束成形算法. 南京大学学报( 自然科学) , 2005, 41( 6) : 675~ 679). [ 11] Scaglione A, Giannakis G B, Barbarossa S. Redundant filterbank precoders and equalizers part II: blind channel estimation, synchronization, and direct equalization. IEEE Transactions on Signal Processing, 1999, 47(7): 2007~ 2022. [ 12] Haas E. Aeronautical channel modeling. IEEE T ransactions on Vehicular T echnology, 2002, 51(2): 254~ 264. [ 13] Lau V K N. Peak-to -average ratio ( PAR) reduction by Walsh-code selection for IS95 and CDMA2000 systems. IEE Proceedings of Communications, 2000, 147(6) : 361~ 364. |
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