Capacity comparison of turbo and convolutional codes in multi-cell DS-CDMA systems

The reverse-link capacity of multi-cell DS-CDMA systems is compared for turbo and convolutional codes, where the distribution of multiple-access interference is approximated as Gaussian in the decoding process. Frame sizes and processing gains representing narrow- and wide-band DS-CDMA systems are examined. Simulation results show that the accuracy of Gaussian approximation is acceptable for the reverse-link application. While marginal improvement is observed in narrow-band turbo-coded DS-CDMA systems, turbo codes are capable of doubling the capacity over conventional codes in wide-band DS-CDMA systems.