Adaptive quadrature amplitude modulation (AQAM) techniques for optimizing long-range underwater acoustic signal transmission

Adaptive quadrature amplitude modulation (AQAM) techniques for optimizing long-range underwater acoustic signal transmission

연구 분야: Infrastructure

학회: Signal, Image and Video Processing

Underwater acoustic communication (UAC) faces numerous challenges such as multipath propagation, Doppler effect, bandwidth limitation, and high ambient noise, which can affect the data rate, latency, range, energy efficiency, and system adaptability to underwater environmental changes. This paper presents an adaptive quadrature amplitude modulation (AQAM) method that offers a promising solution for UAC. By adaptively adjusting the order of the modulation based on real-time channel conditions by employing adaptive equalization algorithms, least mean square (LMS) and minimum mean square error (MMSE) equalizers can support increased data rates while offering stable long-distance communication in challenging conditions. The results of the suggested work demonstrate a significant improvement in bandwidth efficiency of 5 bps/Hz, signal-to-noise ratio (SNR) of 11 dB at 10 km, and bit error rate (BER) of 9 × 10− 3 at 5 km and 1 × 10 − 3 at 10 km using the LMS technique for long-range underwater communication. This indicates that AQAM is an effective scheme for enhancing the performance of UAC systems and enables the use of lower-order QAM under adverse conditions to maintain communication reliability. The results indicate the potential of AQAM to enhance the system reliability, capacity, and energy efficiency in future UAC deployments.