Spectral efficient modulation schemes in a SFH-TDMA orthogonal frequency division multiplexing (OFDM) wireless communication system to support advanced services

An OFDM based wireless communication system with 'slow frequency hopping' (SFH) and TDMA is proposed. SFH-TDMA was found to be superior in performance compared to CDMA regarding intra-cell interference and simple TDMA regarding interference and frequency diversity. OFDM supports a high spectral efficiency and superior performance in various channel profiles without the need for complex equalising in any delay profile. Modulation schemes were developed to support specific C/I conditions for different environments (e.g. office, vehicular) and optimise the system capacity, spectral efficiency and data throughput. We compare coherent (4-PSK, 16-QAM and 64-QAM) and non-coherent (DQPSK, D8PSK, 16-DAPSK) modulation schemes in combination with variable forward error correction to support advanced services. Results of the research are proposed for the standardisation of the 3/sup rd/ generation mobile communication system in Europe and Japan.