Spectrum Spreading Effect of Bandwidth Expansion on Spectral Efficiency of Cellular Systems

Based on a six eo-channel interference model, this paper examines the effect of bandwidth expansiodspectrum spreading beyond the baseband, on the spectral efficiency of wideband and spread spectrum cellular systems. The improvement in the signal to noise ralio/protection ratio as a result of bandwidth expansion is considered. The advantage in the protection ratio combined with the resulting expanded channel spacing are weighed using an equation devised by the authors to deduce whether or not such expansion is spectrally justifiable. Various analogue and digital systems ,are considered. The Shannon model is treated as an ideal modulation system and SSB is taken as a reference where bandwidth expansion is not employed.