Ciência-IUL
Publicações
Descrição Detalhada da Publicação
On the correlation of spreading sequences combined with nonlinear OQPSK signals
Proceedings of the 8th IASTED International Conference on Signal Processing, Pattern Recognition, and Applications, SPPRA 2011
Ano (publicação definitiva)
2011
Língua
Inglês
País
Áustria
Mais Informação
Web of Science®
Esta publicação não está indexada na Web of Science®
Scopus
Google Scholar
Esta publicação não está indexada no Google Scholar
Abstract/Resumo
This paper investigates the main correlation properties of some spreading sequences when applied to a system using nonlinear OQPSK-type modulations, since this is an important topic for present and future wireless communications. These signals, that include as special cases CPM schemes (Continuous-Phase Modulation), can be designed to have very low envelope fluctuations or even a constant envelope, making them compatible with a very low cost and power efficient grossly nonlinear amplification. We use an analytical method to derive both the autocorrelation and the cross-correlation of those signals. The resulting expressions are then applied to Maximum-Length (ML) sequences, Gold Codes and TCH (Tomlinson, Cercas, Hughes) sequences. It is shown that TCH sequences have better autocorrelation and cross-correlation properties when submitted to a nonlinear system. These results can be applied in multi-user detection, spreading, synchronization, channel estimation and many other relevant issues for the radio interface of any communication system.
Agradecimentos/Acknowledgements
--
Palavras-chave
Correlation; Nonlinear OQPSK-type modulations; Pseudo-random sequences
Classificação Fields of Science and Technology
- Ciências Físicas - Ciências Naturais