The Crypto Transmission in HF Wireless Environment

An efficient interleaving algorithm is applied to reduce the loss of ciphered MELP encoding information when a cipher system transmits over a wireless HF fading channel environment. As such, a new scheme for deciding the interleaving depth over a wireless environment is described. Simulations confirm that the proposed efficient algorithm with a variable interleaving depth produces a better performance over a HF fading channel than a static depth with a fixed interleaving depth. Experimental results showed that the BER performance of the proposed efficient interleaving scheme is higher than that of the fixed interleaving depth scheme. Of particular note is that the dynamic allocation algorithm (DAA) reduces degraded error bits by up to 25%, compared with static allocation algorithm (SAA) of depth 48 in HF channel.