Designing DS-CDMA spreading sequences via a low-complexity deterministic approach

This paper presents a novel deterministic technique for the generation of DS-CDMA signature sequences with a wide range of correlation properties that is based on a trellis structure and a trellis-exploration algorithm. A low-complexity implementation of the algorithm is then derived by decomposing the calculation of the metric used to generate the codeset. This approach provides a fast method of generating binary or polyphase codes with no inherent constraints on code length or size of the codeset. In addition, the algorithm is iterative and provides increasingly better codes in terms of average mean-square aperiodic correlation properties as the number of iterations increases. The algorithm is shown to outperform existing complex-code design techniques and provides codes with similar correlation properties to well-known codesets while using significantly fewer unique phases