一种新的应用于多载波码分多址系统的干扰对消算法  

A Novel Interference Cancellation Method in MC-DS-CDMA Systems

作　　者：王明曙[1] 陆建华[1] 周祖成[1] 

机构地区：[1]清华大学电子工程系,北京100084

出　　处：《电子学报》2005年第3期507-510,共4页Acta Electronica Sinica

基　　金：国家自然科学基金 (No .60 1 32 0 1 0 ;No.60 32 81 0 3)

摘　　要：本文提出了一种适用于多载波直扩码分多址系统 (MC -DS- CDMA)上行信道的低复杂度部分并行干扰对消 (LC -PPIC)算法 .该算法充分利用MC -DS -CDMA系统的信道估计与子载波分集 ,在各个子载波上将用户分为可靠 ,普通和无效三类 ,对可靠用户进行干扰对消处理并消去后 ,再对普通用户进行相同操作 ,并放弃无效用户 ,最后将各个子载波上的结果通过最大比合并 (MRC)输出 .这样 ,在降低运算复杂度的同时 ,更好地抑制了多址干扰 (MAI) .通过仿真比较 ,可以看出LC PPIC算法的误码率 (BER)性能明显优于置于载波合并前后的两种部分并行干扰对消 (PPIC)算法 ,特别是在系统负载较重和信噪比较高的情况下 ,这种优势十分显著 .This paper proposes a low complexity partial parallel interference cancellation (LC-PPIC) scheme for an uplink multi-carrier direct sequence code division mul tiple access (MC-DS-CDMA) system.Specifically the proposed algorithm utilizes the results of channel estimation to classify users as reliable,invalid or ordin ary in every subscriber.Reliable users are first subtracted after performing pa rtial parallel interference cancellation (PPIC),while,thereafter,the same proces s is executed among ordinary users,and invalid users are ignored.Finally,maximal ratio combining (MRC) is carried out for reliable and ordinary users to come up with the final detection results.It is worth noting that the algorithm takes ad vantage of channel estimation and frequency diversity,achieving improved perform ance with only a little increase in implementation complexity.Simulation results show that the proposed LC-PPIC detector outperforms both the after-MRC PPIC d etector and the before-MRC detector,especially in a high system load and high s ignal to noise ratio (SNR) case.

关 键 词：多载波直扩码分多址系统 低复杂度部分并行干扰对消算法 

分 类 号：TM15[电气工程—电工理论与新技术]