  A new adaptive receiver design for the Multicarrier (MC) DS-CDMA is proposed
employing successive interference cancellation (SIC) architecture. One of the
main problems limiting the performance of SIC in MC DS-CDMA is the imperfect
estimation of multiple access interference (MAI), and hence, the limited
frequency diversity gain achieved in multipath fading channels. In this paper,
we design a blind adaptive SIC with new multiple access interference
suppression capability implemented within despreading process to improve both
detection and cancellation processes. Furthermore, dynamic scaling factors
derived from the despreader weights are used for interference cancellation
process. This method applied on each subcarrier is followed by maximum ratio or
equal gain combining to fully exploit the frequency diversity inherent in the
multicarrier CDMA systems. It is shown that this way of MAI estimation on
individual subcarrier provides significantly improved performance for a MC
DS-CDMA system compared to that with conventional matched filter (MF) and SIC
techniques at a little added complexity. Performance evaluation under severe
nearfar, fading correlation and system loading conditions are carried out to
affirm the gain of the proposed adaptive receiver design approach.
