DS-CDMA chip waveform design for optimal power-bandwidth performance

The effect of chip waveform shaping on the power efficiency and spectral occupancy of DS-CDMA communication systems is investigated assuming random sequences and coherent reception. A method for designing optimum chip waveforms that minimise the average power of the multiple access interference at a given bandwidth occupancy is derived. The performance improvements of the optimally designed chip waveforms are illustrated by comparing the achieved SIR gain and capacity increase with the figures of some known examples of modulation schemes (such as OQPSK and MSK) that employ conventional chip shaping pulses.