The Research On SNR Estimation And Encryption Technology In Short-wave Communication System

In short-wave communication system, signal SNR is a great significant parameter of measuring channel quality. Several classic SNR estimation algorithms are analysed in this thesis, mainly including ML algorithm, h0algorithm, MMSE algorithm, M2M4algorithm. The simulation shows that in the condition of Gaussian white noise channel, the above algorithms can obtain ideal SNR estimation performance. In this thesis, the updated algorithm based on original ML algorithm is presented. Theoretical derivation and simulation is given. SNR performance estimated by this algorithm can basically meet the requirements of the actual channel estimation on the multipath and faded channel condition.DES encryption algorithm and encryption protection for the software and hardware platform with intellectual property rights are researched in the thesis. The way about encryption protection is to write a string of random number into a group of EF files in the encryption chip named H88SXX,then to read the random number of any EF file in different baud rate,at last to compare this number with the copy. If the result is completely same, the authentication is passed.