Multiple access interference (MAI) canceller enhanced RAKE receiver for asynchronous CDMA system in multipath channels

We propose and study a receiver structure for an asynchronous CDMA system which incorporates a MAI canceller in a RAKE receiver structure. The strong MAI components are first estimated along with the channel impulse responses and separate operations of MAI cancellation and RAKE combining performed. Results show that for a CDMA channel loading of about 17%, the proposed receiver structure has a better BER performance than when either the MAI canceller or the RAKE receiver is used on its own by over 2 dB for the MAI canceller and by over 4 dB for the RAKE receiver at 10 dB E_b/N₀