The Research Of Spectrum Detection In Cognitive Underwater Acoustic Communication

As human uses the sea resource more widely,the underwater communication and spectrum demands are ever-growing.Underwater acoustic communication is developing from original point-to-point communication to multi-users networked communication.As more and more users in underwater acoustic communication,the open and available underwater spectrum resource is limited.Then multi-users use the same frequency band and lead to data collision,which causes the low communication quality.However,cognitive radio successfully eases the situation of limited frequency spectrum resource in the land wireless communication network,which becomes research hotspot in the wireless communication field as a new wireless communication technique.Underwater acoustic communication uses sound wave to transmit data,which is similar to wireless communication.The cognitive underwater acoustic communication is proposed,based on cognitive radio,which presents new research direction to solve the distribution of frequency spectrum resource and development of spectrum efficiency underwater.The main research of the paper is spectrum detection algorithm of cognitive underwater acoustic communication,the main work is as follows:1.First,this paper expounded the character,the model of the underwater acoustic channel and the key technique of cognitive radio.The key point of this part is spectrum detection,which analyzes the merit and demerit of some basic detection algorithms and laid a solid foundation for the follow-up research of spectrum detection in underwater acoustic communication.2.Based on the above research,multiband joint detection method is applied to spectrum detection in underwater communication,the paper establish the math model and change the model to the constraint optimization problem with the aim of biggest throughput capacity.This paper will use the particle swarm optimization algorithm to solve the optimization problem.The simulation results demonstrate that the approach with optimization is more effective and advanced than the conventional technique with the same interference constraint.3.Aiming at solving the problem of limited hardware resource,energy saving and the sparsity of underwater frequency spectrum,this paper applies compressed sensing to the energy detection algorithm.Then this paper presents spectrum sensing based on thespectrum of differential signal compression perception which detects differential signal instead of the detection signal as the criterion of spectrum occupation changing.The simulation manifests that the algorithm in this paper can lower the number of iteration,reduce calculated amount and get better detection performance than the traditional spectrum detection.