Research And Application Of Syndrome Coding For Physical Layer Security

With the rapid changing of wireless communication technology,the security demand of channel transmission has increased to a new level.Considering that the traditional channel coding is usually from the prospective of improving the reliability of the transmission,it does little on the improvement of the safety performance.Moreover,it is easy for this scheme to receive the various constraints from channel quality,transmission rate and so on.Syndrome coding is a typical scheme of physical layer security.Opposed to the traditional channel coding,the advantage of syndrome coding is that it make full use of the total codeword space and introduce the random redundancy in the form of coset mapping.Therefore,it has better randomicity and security and is of great significance for the security transmission of secrecy message in wiretap channel,which has made it one of the hot issues in recent years.The existing researches of syndrome coding are mostly in the prospective of improving the systematic structure and increasing the channel difference.However,the task of how to design the secure code combining with the characteristics of the code itself as well as the related knowledge of the information security theory is urgent and necessary.On the other hand,considering that the calculated amount and complexity is a little high,it is also difficult to consider how to efficiently increase the coding and decoding efficiency.To solve the problem above,this paper conducts the study in the following aspects:1.Firstly,by analyzing the security mechanism of physical layer security coding and syndrome coding,we study the relationship between the security of syndrome coding and the dual code of the mother code on.Moreover,we amend the traditional coding scheme of syndrome coding and solve the problem that the coding process takes up too much memory.The scheme efficiently increases the coding efficiency.2.Secondly,under the circumstance of a noiseless main channel,we set up a system model of syndrome coding based on binary random linear code and use a sort of recusive algorithm of equivocation,which decreases the complexity of the calculation on equivocation.We proposed a syndrome code construction algorithm based on the optimization of minimum distance.The proposed algorithm can require the mother code of syndrome coding which has the best security and therefore promote the security of syndrome coding.3.Finally,under the circumstance of a noisy main channel,we combine the fountain code which has a good performance of reliability with syndrome coding and set up a system model which ensures the secure and reliable transmission.Based on the important factor,degree distribution,we focus on the design of the degree distribution that reaches the secure requirement.We proposed a optimized particle swarm algorithm based on chaos and by using this algorithm the degree distribution we require,to some extent,does promote the secure performance of fountain coding.The system we construct here has both good reliability and security.