DECISION-FEEDBACK EQUALIZATION FOR CDMA IN INDOOR WIRELESS COMMUNICATIONS

Commercial interest in Code Division Multiple Access (CDMA) systems ha s risen dramatically in the last few years. It yields a potential incr ease in capacity over other access schemes, because it provides protec tion against interference, multipath, fading, and jamming. Recently, s everal interference cancellation schemes for CDMA have been proposed b ut they require information about all interfering active users or some channel parameters. In this paper, we present an adaptive fractionall y spaced decison feedback equalizer (DFE) for a CDMA system in an indo or wireless Rayleigh fading environment. This system only uses informa tion about the desired user's spreading code and a training sequence. An analysis on the optimum performance of the DFE receiver shows the a dvantages of this system over others in terms of capacity improvements . A simulation of this system is also presented to study the convergen ce properties and implementation considerations of the DFE receiver. E ffects on the performance because of sudden birth and death of users i n the CDMA system and bit error rate performance of the DFE receiver i s also presented.