Design And ASIC Implementation Of Signal-to-noise Ratio Algorithm For Satellite Channel

This paper focuses on the selection of channel SNR algorithm,SNR algorithm code design,AGC digital detection code design,ASIC code conversion design,hardware platform test and verification.In order to study the signal-to-noise ratio estimation of satellite channel,the theoretical knowledge of signal-to-noise ratio estimation is introduced in the second chapter.According to the characteristics of satellite communication channel,the signal-to-noise ratio estimation is assumed to be Gaussian white noise channel.Six SNR estimation algorithms are compared: maximum likelihood algorithm,second-order moment-fourth-order moment algorithm,split symbol moment method,error vector method,signal noise variance method,data fitting method to verify the simulation results.The correctness and limitation of these algorithms are illustrated.Finally,the conclusion that the second-fourth-order moment algorithm is adopted in this paper is given.Then the selection of the length of the receiving sequence and A are given through the practical application of the satellite.GC locking interval selection principle.In the third chapter,according to the software design flow,this chapter introduces the method of signal-to-noise ratio estimation and digital detection software code,and points for attention.Finally,through the data source input simulation,it shows that it can meet the requirements of satellite in-orbit use.In the fourth chapter,the development process of ASIC is introduced firstly,and the emphasis of adaptive repair of RTL code is discussed in combination with this topic.Secondly,the architecture of the ASIC chip which includes SNR estimation is given,and the software testing and verification is given.The rationality of algorithm selection,code programming and development process control is proved.In the fifth chapter,the single machine function of the test is introduced,then the purpose and method of SNR estimation test are described,and then the comparison of the measured data of normal temperature and atmospheric pressure,mechanics test and temperature test is made,and the test data are compared with those of normal temperature and atmospheric pressure,mechanical test and temperature test.It can be seen that the design of the ASIC chip meets the requirements of satellite mechanical design.In normal temperature,atmospheric pressure and temperature tests,the demodulation information rate is 80 Mbpsand the input signal-to-noise ratio is 0.6 dB in the 5.5dB-12.5dB range.Under the condition of meeting the requirement of 80% satellite margin,the estimation accuracy is less than that of 1dB.