Adaptive rate coding for wideband CDMA wireless networks

One method of optimizing throughput for a wireless system while maintaining a certain level of performance is to design the error control system so that it offers two or more different rate codes. The system uses channel-state information to determine which of the various codes should be used at any given moment. In order to minimize system complexity, the same encoder and decoder are used for the different rate codes. This paper presents a method of comparing the performance of the system for different rate convolutional codes. The results show the optimal code rate for various channel conditions and the gain in throughput by using adaptive rate codes in a wideband CDMA system.