Spectral efficiency of adaptive hybrid DS/FFH CDMA in Rayleigh fading

The spectral efficiency of an adaptive hybrid direct-sequence/fast frequency hopping code-division multiple-access (DS/FFH-CDMA) system operating in Rayleigh fading is estimated in terms of the theoretically achievable average channel capacity (in the Shannon sense) per user. The work covers the operation of the examined adaptive hybrid DS/FFH-CDMA system over a broadcast communication randomly time-varying channel applicable to the downlink of satellites, wireless local area networks and single-cell indoor mobile systems and leads to a closed-form expression for the achieved spectral efficiency.