Research Of Key Technologies On The Receiving Of Burst Signal

Based on the protocol of MIL-STD-188-141B and the work done by others, this thesis focuses on the key technologies about physical layer. Both sending and receiving schemes are improved and implemented in this thesis, and the emphasis is the receiving scheme.According to the condition of shortwave channels and the existing DSP hardware system, the thesis develops the schemes about the receiver. Some key technologies are adopted in the schemes. Error control scheme including CRC check, convolutional coding, interleaving and Rake receiver are adopted to resist the effect of the fading. Sliding subsection correlation-FFT technique is adopted to realize Pseudonoise synchronization under the conditions of low SNR and big frequency-offset. After pseudonoise synchronization and bit synchronization, conic fitting is introduced to improve the precision of frequency-offset estimation separately. The timing recovery mode is used to rectify the warp of A/D sampling. Correlating and FFT method are adopted to estimate the value of channel quality.Simulated with MATLAB, the improved schemes are implemented with C language on the TMS320VC5509 DSP hardware platform. The demands of the protocol, automatic link establishment and the Point to Point data transmission of low-rate are tested using the channel simulator, the results show that it has been improved significantly, and basically reaches the requirements of the protocol.