.pcm / Fm Reentry Telemetry Channel Waveform Design Method

Organization of Pulse Code Modulation/Frequency Modulation (PCM/FM) is widely used in most Reentry Remote Sensing (RRS) system at the present time in our country. The typical PCM/FM RRS channel include transmitter on missile,wireless transmission channel,receiver on the ground. Nowadays, the existing RRS system in our country can work effectually when transmitting signals below 500 Kbps bit rate because the ample system power can compensate various distortions and fading consisted in RRS channel. But power allowance can't guarantee the system to reach the bit rate error quota because of the system's inherent limit when the bit rate is above 1 Mbps. So, On the basis of studying the characteristic of all channel components respective, researching the effect on PCM/FM signal which cause by the character of the RRS channel, designing the shapeing filtering by thinking of the transmission organization, all of those can give references to design reentry remote sensing system rationally in engineering applications, and would be the foundation of using channel proportion technology to decrease the error rate of PCM/FM system. The main content in this dissertation are as follws: 1.In section 2, the choice of PCM/FM RRS Organization and the PCM code types are analysed. Then, the shortage and the advantage of PCM/FM RRS organization are discussed. 2.In section 3, the capacity of PCM/FM channel is analysed with the view of information theoty. Then, the two-point-inject phase-locked FM transmitter and the phase-locked frequency discrimination receiver are analysed. Their theory model are builded, and are emulated in matlab. 3.In section 4, the models of RRS wireless channel are discussed, included two-path model, rayleigh fast/slow model, rice model. And a new model is presented: generalized three-path model. All model's performance are analysed and emulated in matlab. 4.In section 5, the shape filtering network is designed by think of the RRS system character, and a lot of simulation has done in matlab. Then, some helpful conclusions are given. 5.In section 6, the way of compound programming with Matlab and Visual c++ are summarized, and a demo software running without matlab is accomplished according with the simulations in section 3~5.