Performance of an Improved Modified MMSE Receiver for CDMA Systems in Rayleigh Fading†

Abstract  In this paper, the bit error rate of a recently proposed modified minimum mean squared error (MMSE) detector in Rayleigh flat fading channels is improved. It is also shown that the new detector is less sensitive to changes in the number of users. This improved detector is then adapted for use in a Rayleigh faded frequency-selective channel. An asynchronous binary phase shift keying (BPSK) direct sequence code division multiple access (DS/ CDMA) system is assumed, with pilot symbols inserted into the data stream, for channel estimation.