Patent ID: 7440492

Claim:
A method of canceling interference in a CDMA receiver of a mobile station that receives from a base station a spread spectrum signal containing a varying number of data channels depending on a number of mobile users simultaneously communicating with the base station, comprising the steps of: a) generating different spread codes corresponding to a maximum number of data channels that can be assigned to said mobile station; b) despreading the received data channels with spread codes of the received data channels to produce a plurality of despread data channel signals; c) demodulating said despread data channel signals and making a decision on the demodulated data channel signals to detect a first plurality of symbol replicas and re-modulating said first plurality of symbol replicas; d) re-spreading the re-modulated symbol replicas with the spread codes of the received data channels to produce a plurality of re-spread interference replicas; e) enabling each of the re-spread interference replica in the plurality if a spread code of a corresponding despread data channel signal coincides with a spread code of a data channel assigned to the mobile station by the communicating base station; f) summing said enabled re-spread interference replicas to produce a combined re-spread interference replica; g) subtracting said combined re-spread interference replica from a delayed spread spectrum signal to produce a residual signal; h) summing said residual signal with said enabled re-spread interference replicas to produce a plurality of combined signals; i) despreading said plurality of combined signals to produce a plurality of despread combined signals; j) detecting a second plurality of symbol replicas from said despread combined signals; k) decoding said second plurality of symbol replicas; and l) diversity combining said decoded second plurality of symbol replicas.