Research Article
Sequence Design for Symbol-Asynchronous CDMA with Power or Rate Constraints
@INPROCEEDINGS{10.1109/COMSWA.2007.382450, author={Jyothiram Kasturi and Rajesh Sundaresan}, title={Sequence Design for Symbol-Asynchronous CDMA with Power or Rate Constraints}, proceedings={1st International IEEE Workshop on WIreless Systems: Advanced Research and Development}, publisher={IEEE}, proceedings_a={WISARD}, year={2007}, month={7}, keywords={asynchronous code division multiple access resource allocation sum capacity uplink}, doi={10.1109/COMSWA.2007.382450} }- Jyothiram Kasturi
Rajesh Sundaresan
Year: 2007
Sequence Design for Symbol-Asynchronous CDMA with Power or Rate Constraints
WISARD
IEEE
DOI: 10.1109/COMSWA.2007.382450
Abstract
Sequence design and resource allocation for a symbol-asynchronous chip-synchronous code division multiple access (CDMA) system is considered in this paper. A simple lower bound on the minimum sum-power required for a non-oversized system, based on the best achievable for a non-spread system, and an analogous upper bound on the sum rate are first summarised. Subsequently, an algorithm of Sundaresan and Padakandla is shown to achieve the lower bound on minimum sum power (upper bound on sum rate, respectively). Analogous to the synchronous case, by splitting oversized users in a system with processing gain N, a system with no oversized users is easily obtained, and the lower bound on sum power (upper bound on sum rate, respectively) is shown to be achieved by using N orthogonal sequences. The total number of splits is at most N-1.