Analysis of serial and parallel soft input decryption schemes over a wireless channel

Wireless communication systems and the applications developed for it are increasing day by day, mainly due to the inherent mobility that it offers. Amongst the most popular applications over the wireless communication networks are cellular telephony, web browsing, Simple Messaging Service, Multimedia Messaging Service and video conferencing. Communication over a wireless channel, however, has two inherent problems namely security and transmission errors. Both the issues are researched and dealt separately with sufficient literature available. However these solutions were dealt separately so far. The authors have developed and published earlier some results on the method of joint channel coding and cryptography, which combines data security and error correction by utilizing the data produced by a digital signature scheme, for the correction of transmission errors. This paper takes further the idea of joint channel coding and cryptography and analyses the serial and parallel soft input decryption schemes for joint channel coding and cryptography. We have already shown that joint channel coding and cryptography provides a coding gain over a convolutional code of same rate. Here in this paper we discuss and evaluate the performance of two schemes namely the serial and parallel methods for Soft input decryption and show that the parallel technique provides a further coding gain over the serial scheme.