一种基于波形集设计的降低异步DS-CDMA系统多址干扰的新方法  

A Novel Method to Reduce the Multi-address Interference for Asynchronous DS-CDMA System Based on Waveform-sets Designing

作　　者：郭黎利[1] 李清伟[1] 董雪 

机构地区：[1]哈尔滨工程大学信息与通信工程学院,哈尔滨150001

出　　处：《电子与信息学报》2017年第7期1681-1687,共7页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(61271263)~~

摘　　要：已有研究指出,在异步DS-CDMA系统中,每个用户chip码元使用常规7种波形中的双波形(DW)可以有效地降低多址干扰。该文提出一种基于波形集(WS)设计降低多址干扰的新方法。对于任意多的用户,均可以设计出由常规7种波形中2种或者3种波形构成的WS。相对于DW方法,每个用户只需要使用WS中的单一波形就可以进一步提升其输出端的信干噪比(SINR)和误码率(BER)性能。该文不仅给出了新方法中使用不同波形用户接收端的SINR计算公式,同时给出了不同波形用户改进高斯近似(IGA)下的BER。理论推导和实验仿真证实了:IGA与高斯近似(GA)的BER相比,具有与实际仿真曲线更好的重合度;新方法 IGA下BER推导的准确性;基于WS的新方法相对于已有的DW方法可以进一步降低MAI以及提升多用户的SINR和BER性能。It is shown that the Multi-Address Interference （MAI） can be effectively reduced when Double Waveforms （DW） are used with chip code in the asynchronous DS-CDMA system. A novel method to reduce the MAI based on Waveform Sets （WS） is proposed. For any number of users, each user can choose single waveform from the WS that can be designed with only two or three kinds of seven conventional waveforms, and can obtain better Signal to Interference plus Noise Ratio （SINR） and Bit Error Rate （BER） performance than DW method. The analytical expression of SINR at the output of each correlation receiver for the proposed method is given. Besides, the BER by Improved Gaussian Approximation （IGA） over an additive white Gaussian noise channel is derived. Relative to the existing DW method, it is shown that the proposed method can further improve the SINR and BER performance through theoretical analysis and simulation results. The overlap between simulation curves and theoretical BER curves with IGA proves that the accuracy of BER with IGA outweighs BER with Gaussian approximation （GA）.

关 键 词：异步DS-CDMA 波形集 信干噪比 改进高斯近似 误码率 

分 类 号：TN914.53[电子电信—通信与信息系统]