Direct sequence CDMA power control, interleaving, and coding

The authors develop and analyze models of power control that consider other aspects of code-division multiple access (CDMA) systems, such as interleaving and coding on the land mobile radio channel. The orientation is that a power control scheme keeps the received powers at the base station almost equal, and the performance degradation incurred if the powers are not exactly equal will be quantified. In doing so, the authors consider the performance implications of control latency and a maximum speech delay constraint. Because of positive correlations between the fading channel amplitudes, the effectiveness of the combination of interleaving and coding in combating the effects of power variations due to slow Rayleigh fading is reduced. It is shown that power control and interleaving/coding are most effective in complementary parameter regions, thus providing a degree of robustness for both fast and slow Rayleigh fading