Baseband processing techniques for Code Division Multiple Access (CDMA) systems generally fall into two broad categories: error coding and signal spreading. This thesis addresses these issues for the Wideband CDMA (WCDMA) baseband receiver. The Third Generation Partnership Protocol (3GPP) standards will be used in specifying the system model. 3GPP systems support two forms of error coding, i.e., convolutional coding and Turbo coding. A Viterbi decoder is developed for convolutional codes to optimize the likelihood of the estimated information sequence. For Turbo coding, a Turbo decoder, which...