Research On 8FSK Identification And ALE Link Estimation In HF Communication

HF communication is of important applications in the military and civilian systems. Automatic Link Establishment(ALE) is an important technique in HF communication. The key techniques of Automatic Link Establishment are frequency offset estimation, SNR estimation, synchronization and so on.The recognition of 2G 8FSK modulation signal is introduced, then according to our national military standard GJB2077-94, the basic content of the ALE agreement is described in this thesis. 8FSK signal modulation and demodulation techniques, forward error correction techniques have been studied and simulated. The method of combining FFT and Chirp Z Transform is used for the frequency offset estimation of the received signal, and the method of adding the Hanning Windows on the signal is used for the SNR estimation, and the two methods which are sliding FFT method and the Goertzel algorithm are used for the symbol synchronization in this thesis. The simulations of the algorithms are completed, and the programs are realized on the DSP TMS320C6713 system.Finally, the work of the thesis is summarized and some advices are given about the future work.