Two-stage maximum likelihood estimation (TSMLE) for MT-CDMA signals

This paper proposes a new type of receiver for MT-CDMA signals, which is based on the two-stage maximum likelihood estimation (TSMLE). The first stage of the TSMLE performs the channel estimation considering either the received symbol or the estimate of the received symbol is known while the second stage uses this estimated channel information to estimate the next symbol. The performance of this receiver is investigated in terms of the bit error rate (BER) for a multipath, slowly Rayleigh fading channel in the indoor environment. The multiple access interference (MAI) is taken into account. A model for the computation of average bit error probability is derived for quadrature phase shift keying (QPSK) modulation. The influence of number of tones is studied for given bandwidth (BW), bit rate and transmission power