Efficient bandwidth utilisation for CDMA using convolutional codes

This paper investigates the use of nonlinear convolutional coding techniques for use in a DS-CDMA cellular communication system. Particular attention is paid to the relative proportions of convolutional coding and direct sequence spreading which offer the most efficient use of the available processing gain. The dependency of the optimal strategy on various factors, including background noise level, number of active users and coding power is discussed. Future developments are indicated including the possible application of this system to multipath channels, and the use of other coding structures