Joint detection with coherent receiver antenna diversity in CDMAmobile radio systems

摘要

In code division multiple access (CDMA) mobile radio systems, bothnintersymbol interference and multiple access interference arise whichncan be combated by using either elaborate optimum or favorablensuboptimum joint detection (JD) techniques. Furthermore, the timenvariation of the radio channels leads to degradations of the receivernperformance. These degradations can be reduced by applying diversityntechniques. Using coherent receiver antenna diversity (CRAD) isnespecially attractive because only the signal processing at the receivernmust be modified. In the present paper, the application of CRAD to thenmore critical uplink of CDMA mobile radio systems with suboptimum JDntechniques is investigated for maximal-ratio combining. The authorsnstudy six different suboptimum JD techniques based on decorrelatingnmatched filtering, Gauss-Markov estimation, and minimum mean squarenerror estimation with and without decision feedback. These sixnsuboptimum JD techniques which are well-known for single antennanreceivers are extended for the application to CRAD. A main concern ofnthe paper is the determining of the SNR performance of the presented JDntechniques for CRAD and the achievable average uncoded bit errornprobabilities for the transmission over rural area, typical urban andnbad urban mobile radio channels are determined