Design And Implementation Of Burst Communication System Based On Voice Interface

With the rapid development of radio communication technology,the spectrum resources become more and more tense,the future communication environment will be more and more bad.As the main means of communication in military application,radio station has the advantages of small size,light weight and high maneuverability.Because of the exposure and openness of electromagnetic waves,radio signals are easy to monitor,decipher and interfere,in which case,how to conceal the transmission of wireless signals becomes very important.How to conceal oneself on the battlefield of complex change and also can carry on the external communication,these have put forward the higher request to the battlefield communication location and so on design.Burst communication is also known as burst communication,it is the normal rate information encapsulation,and then the high-speed data mode random burst,the receiver will receive the signal back to the original information of a radio communication.Because the communication time is very short(usually less than 1 seconds),the other time in a static state,the sending time is random,so the burst signal is difficult to be investigated,interception,thus greatly improving the communication security,concealment and antiinterference ability.This paper discusses the use of a FPGA+DSP digital platform,the use of software radio technology,software embedded through the burst of communication waveform development,the use of Am+msk modulation and demodulation technology to achieve the transmission of data information on the audio channel.Can be in the car,fishing boats,aircraft and other platforms with voice communication functions between the multiple radio to achieve the function of data transmission,with technical versatility,in the future can be extended to control,communications,search and rescue business scope.In this paper,the technology of using speech interface to realize burst communication is studied,the design and implementation of burst communication using Am+MSK modulation and demodulation method is studied,the design of hardware circuit device selection is carried out,the software simulation and hardware realization and the actual test are carried out,and the paper chooses Am+MSK in the modulation and demodulation The modulation and demodulation method of MSK is compared with the advantages and disadvantages of the delay difference demodulation method and the square-loop coherent demodulation method for MSK signal demodulation,and an improved square-loop demodulation method is proposed,which can reduce the frequency-division operation and greatly simplify the FPGA resources.According to the index requirement,the scheme of the hardware unit can design and carry out the device selection,according to the software scheme,the Loop filter design and the phase-locked loop low-pass filter are designed,and the design results are realized by the VHDL language code,which shows the simulation result and conforms to the design.And the DSP software process design instructions.Because the existing experimental hardware platform lacks the audio A/D and D/A conversion module,it makes am modulation on the MSK waveform so that the whole waveform and burst time are validated in the intermediate frequency interface.The whole waveform was tested and validated by using Altera fpga-EP3C120F48417 Nand Ti's dsp-TMS320VC5509 A.The results of MSK modulation and demodulation,AM modulation and burst waveform verification are given in detail.