Design And Simulation Of SCCPM System For Aeronautical Communication

In recent years,with the rapid development of communication technology and the aviation industry,aeronautical communication especially the concept of air WiFi Internet has obtained more and more people's attention.The appeal of passenger air access requires the capability of broadband transmission and more extensive interoperability of aeronautical communication system in the future.On the other hand,the increasing of the air line and flight of civil aviation has aggravated mutual interference of the aeronautical communication system.For the high bandwidth utilization rate,spectrum utilization,and constant envelope of output waveform,Serially Concatenated Continuous Phase Modulation(SCCPM)can meet the demands of high bandwidth utilization in future aeronautical communication and reduce the transmission power effectively of the communication system.Therefore,on the basis of SCCPM,this thesis proposes a new Serially Concatenated Continuous Phase Modulation scheme which is applied to aeronautical communication.The main innovations of this paper are listed as followed:(1)Firstly,the thesis introduces the decomposition model of the Continuous Phase Modulation(CPM)in detail and draw forth Serially Concatenated Continuous Phase Modulation(SCCPM)scheme.For the appeal that iterative decoding of concatenated schemes requires noise variance as a priori knowledge to generate soft information,the paper proposes a noise estimation method based on a limited order difference operator groups.The method filters raw information via higher order difference operator,then combines the method similar to the four bit spacing and median filtering theory to estimate noise variation of communication channel.In the additive Gaussian channel and flat Rayleigh fading channel,compared with the ML and M2M4 algorithms,it can be proved that the proposed method can obtain a better estimation performance,especially in the high SNR and high modulation order.The concatenated simulation demonstrates that the proposed method can accurately estimate the channel noise when the signal-to-noise ratio is more than 3dB in the additive Gaussian channel.(2)Secondly,the thesis presents the convolutional encoding based on model p of integer ring,and introduces the CPM method over rings.The thesis proposes a serially concatenated CPM scheme based on rings.Then combining the theory and simulation,the thesis analyses influences of the the coding sensitivity factors and the modulation sensitivity factors on the performance of the SCCPM system based on ring,respectively.Finally,the paper compares the performance of SCCPM system based on ring and the binary convolutional encoding SCCPM system,and analyses the performance difference in the perspective of minimum distance and the error probability.The results demonstrate that the proposed method can has a signal to noise ratio gain of 1.25-1.75 dB.That is,under the same communication distance,the transmission power of the system is reduced by 1/5.