New effective joint detection technique for multicarrier CDMA wireless systems applying the Walsh codes

The multicarrier CDMA technique applied in mobile radio communication systems is considered. The new fast algorithm for multi-user combining and multicarrier modulation, in a base station transmitter, is presented. It is shown, that the inverse of the proposed algorithm is a very efficient method of multicarrier demodulation and joint multi-user detection. Its applications in base and mobile station receivers is discussed. It is described, how equalization of the selective fading channel, and MAI rejection can effectively be implemented in the time-domain. It is shown, that the computational complexity of such a reception technique is very low. The detailed considerations and simulation results for the down-link transmission are presented. The similar reception method for the up-link case is also considered in detail