Underwater Multiple Access Communication Using Spread Spectrum Scheme

Ultra-wideband (UWB) communication offers high bandwidth with low power spectral density, allowing it to coexist with narrowband systems. However, as the number of users’ increases, Multi-Access Interference (MAI) becomes a significant challenge, impacting the performance of UWB systems. Traditional Spread Spectrum (SS) methods face difficulties modeling MAI due to its complex nature, leading to inaccuracies in signal models and reduced communication efficiency. Fuzzy logic addresses signal model inaccuracies, providing a flexible and effective solution. This study explores using a fuzzy inference system (FIS) detector to mitigate MAI in a multiple-access UWB system. The FIS detector maps input vectors into a fuzzy space, enhancing detection and preventing performance deterioration. Additionally, the use of multistage interference cancellation (MIC) is examined, where interference from other users is iteratively estimated and removed to improve detection accuracy and overall system performance.