Code detection based on generalized Cross-Correlation in DS-CDMA underwater aplications

Underwater Wireless Sensor Network applications require the design of efficient communications links due to the rough environment. Acoustic signals make feasible the data transmission based on Direct Sequence Code Division Multiple Access (DS-CDMA) techniques, because compensates the multipath effect and allow receivers to simultaneously distinguish among multiple independent emitters. For that purpose, cross-correlation techniques based on matched filtering are often used, by detecting at what e instant arrives maximum correlation value is provided. Inter-Symbol Interference (ISI) caused by the Auto-Correlation (AC) function of the used sequences, and the Cross-Correlation (CC) between them, is not null around maximum matching value. This implies that it is sometimes difficult to detect the accurate position of correlation maxima. In order to improve the detection process without applying common communications algorithms for interference compensation, that usually involve a high computational load, the use of Generalized Cross-Correlation (GCC) is here analyzed.