HF Study On Spread Spectrum Radio Sources, Channel Coding And Implementation

In military communication, the information's accurate and un-detective by the enemies are vital to the result of the war. Since the last century, the spread spectrum and hopping spectrum transmitter has been used in military. After about one hundred years developing and improvement, even the basic theory haven't changed much, but as the development of large scale IC there are large sum of and fast digital signal processors. At the same time the theory of software radio make the spread spectrum and hopping spectrum transmitter continue to develop based on the concept of software radio. This dissertion majored in dicussing the signal source and signal transmitting channel's code and decoding of spectrum spread radio station under the concept of the software wirelss radio. The author's main work and new ideas are listed blow:1. Chosen the CVSD as the radio station's voice coding. The character of strong anti-interfere in real communication circumstance was our major consideration to choose CVSD. As to validate the algorithm of CVSD and get the better parameter, we do the CVSD algorithm simulation firstly with MATLAB and the simulation tested the algorithm as well as given us some tips during the hardware debugging.2. The interweaving was used to boost up the ability of anti-interfere. Cause the easy implemented and good effect, the interweaving has been used in almost all wirelss communications. In this paper we just dicussed the bit interweave.3. We adopt the convolution coding to be the channel coding. The coding was easy to implemented and we used the Viterbi algorithm to decode. At the part of hardware we discussed the hardware implement and show the good performance.4. I finished all my works based on the ideas of software wireless radio. I emphasized two parts during my working, the first one is let the others project designers to use my module very easy, and the second one is let enough hardware sources to do the upgrading job.