MULTICARRIER CDMA WITH ADAPTIVE FREQUENCY-HOPPING FOR MOBILE RADIO SYSTEMS

A modified multicarrier (MC) direct-sequence code-division multiple-ac cess (DS-CDMA) system has been proposed for use over slow multipath fa ding channels with frequency selectivity in the reverse link transmiss ion of a cellular network, Instead of transmitting data substreams uni formly through subchannels, data substreams hop over subchannels with the hopping patterns adaptively adjusted to the channel fading charact eristics. The problem of determining the optimal hopping pattern is fo rmulated as a multiobjective optimization problem, for which an effici ent algorithm, based on the water-filling (WF) principle, is designed to solve the problem practically, Simulation results show that the per formance in terms of the average bit-error probability (BEP) (over all users) is better than that of single carrier RAKE receiver systems, c onventional MC CDMA systems applying moderate error protection, or div ersity systems with different combining techniques.