Abstract: An architecture for a wideband code-division multiple access (WCDMA) baseband system is provided. The system comprises separate processing blocks (e.g. cell search, RAKE receiver, transmitter engine, and error correction). Each block comprises a hard-wired logic block and a CSP (communication signal processor). The architecture of each CSP is optimized to perform a particular signal processing function. Each CSP has an associated memory architecture that is optimized for the particular signal processing function. Each memory architecture includes at least two memories that are independently addressable to support simultaneous read and/or write access. The instruction set for each CSP is optimized based on the particular signal processing function. Each instruction set includes instruction words that are optimized for the particular signal processing function. One or more instruction words support simultaneous read/write accesses in parallel.

Abstract: A SWP- (Sub-Word Parallelism-) based RAKE receiver for a Wideband Code-Division Multiple Access (WCDMA) mobile station is optimized to perform channel de-rotation and data combining. The RAKE receiver comprises SIMD (Single Instruction, Multiple Data) instructions, which can perform a complex multiplication for a channel de-rotation in a single cycle. The SIMD instructions can also perform a complex addition for data combining in a single cycle. Optimization of the RAKE receiver reduces power consumption and costs, enhances performance, and provides extensibility for next-generation architectures.

Abstract: A Viterbi decoder generates a branch metric table from first and second data signals taken at two sample times and provides selected branch metrics to an add/compare/select circuit in response to branch indices from a branch index generator. The branch metrics in the branch metric table are the sixteen combinations of the sum of the first and second parallel data signals at first and second sample times and the inverse of such signals. The branch index generator generates the branch indices in response to a received state from the add/compare/select circuit, convolutional code polynomials and the possible states of a radix-4 trellis. The add/compare/select generates a survivor path decision based on the selected branch metrics.