tailieunhanh - Báo cáo hóa học: " Binary De Bruijn sequences for DS-CDMA systems: analysis and results"

Binary De Bruijn sequences for DS-CDMA systems: analysis and results | Spinsante et al. EURASIP Journal on Wireless Communications and Networking 2011 2011 4 EURASIP Journal on . http content 2011 1 4 Wireless Communications and Networking a SpringerOpen Journal RESEARCH Open Access Binary De Bruijn sequences for DS-CDMA systems analysis and results Susanna Spinsante Stefano Andrenacci and Ennio Gambi Abstract Code division multiple access CDMA using direct sequence DS spread spectrum modulation provides multiple access capability essentially thanks to the adoption of proper sequences as spreading codes. The ability of a DS-CDMA receiver to detect the desired signal relies to a great extent on the auto-correlation properties of the spreading code associated to each user on the other hand multi-user interference rejection depends on the crosscorrelation properties of all the spreading codes in the considered set. As a consequence the analysis of new families of spreading codes to be adopted in DS-CDMA is of great interest. This article provides results about the evaluation of specific full-length binary sequences the De Bruijn ones when applied as spreading codes in DS-CDMA schemes and compares their performance to other families of spreading codes commonly used such as m-sequences Gold OVSF and Kasami sequences. While the latter sets of sequences have been specifically designed for application in multi-user communication contexts De Bruijn sequences come from combinatorial mathematics and have been applied in completely different scenarios. Considering the similarity of De Bruijn sequences to random sequences we investigate the performance resulting by applying them as spreading codes. The results herein presented suggest that binary De Bruijn sequences when properly selected may compete with more consolidated options and encourage further investigation activities specifically focused on the generation of longer sequences and the definition of correlation-based selection criteria. Keywords Spreading code De .