ORTHOGONAL MULTICARRIER FREQUENCY HOPPING-CODE DIVISION MULTIPLE-ACCESS SCHEME FOR FREQUENCY-SELECTIVE FADING

To improve frequency efficiency or user capacity in land mobile communication systems, orthogonal multicarrier frequency hopping-code division multiple access (FH-CDMA) is introduced and investigated. Such improvement is achieved by combining orthogonal frequency division multiplexing (OFDM) with FH-CDMA. The theoretical analysis includes bit error rate (BER), required S/N, and maximum bit rate. A modified scheme allowing transmission power to be controlled according to the number of simultaneously accessing users also is discussed. This scheme improves BER performance for frequency-selective fading when the number of simultaneously accessing users in a cellular zone is small.