The Design And Testing Of Underwater Single Sideband Voice Communication

In this paper,an underwater acoustic single sideband voice communication system is implemented by digital operations,and the main functions of the system are tested.Firstly,in modulation aspect,since the communication mode of analog modulation still has a place in underwater communication and has certain advantages that digital modulation does not have,this paper chooses the single-sideband modulation mode of analog modulation to modulate and process the voice signal.At the same time,it is implemented and compared in various ways.In signal processing,this paper describes in detail a number of aspects involved in optimizing the processing of voice signal,including signal framing,endpoint detection,spectral subtraction noise reduction,speech compensation,and so on.The corresponding algorithm is simulated to verify its feasibility.Secondly,this paper studies the impact of underwater channel on the underwater acoustic single-sideband voice communication system,and briefly introduces the characteristics and impact of underwater channel itself.Bellhop is used to complete the simulation of underwater acoustic channel.The estimation of underwater channel is accomplished by using the channel estimation method based on linear frequency modulation signal.For the multipath effect interference caused by the underwater acoustic channel to the single-sideband speech communication system,two methods of removing multipath interference based on direct processing in frequency domain and based on passive time reversal mirror processing are compared,and their effects on the speech recovery of the receiver are analyzed.Thirdly,this paper designs and builds the hardware platform of the system,establishes the parameter values of each index of the system according to the actual situation,and introduces the main module composition and chip selection of the hardware platform,including DSP,voice acquisition,A/D,D/A,power amplifier,preamplifier,etc.In terms of algorithm implementation,the overall software framework and related functions of the algorithm are detailed,including the main program design,voice acquisition,voice and channel processing.Finally,the circuit of the main function modules in the system hardware is tested.After the test is completed,the performance of the whole system is tested in the channel pool and the Songhua River.The experimental data is analyzed and the performance of the system is evaluated.The feasibility of the system is verified,which shows that it meets the design requirements,satisfies the application scenario and draws a conclusion.