The Physical Layer Security Performance Of Wireless Network Based On Cooperation

Cooperative communication and channel coding, being emerging communication techniques, have greatly c ontributed to the im provement of communication system s, no matter in the aspect of capacity or efficiency. The former one is based on the relay communication system. The difference between them is that the relay node is replaced by the user node in cooperative commu nication system . The cooperative communication system gets diversity gain and it also can b e seen as a virtu e MIMO system in the rea lity; while the later on e, d ifferent f rom the trad itional signa l processing mode in som e routing node, wh ich only store-and-forward the received massage, takes certain signal processing m ethod in som e routing nodes in order to improve the performance, such as outage probability, of the communication system.This paper presents dynamic cooperative strategy to forward the received data or Cooperative jamming signal based on channel condition to achieve the physical layer Security.The strategy may ensure a none zero security rate of main channel even when the wiretap channel is b etter than the main channel. Nested Code is used as channel encodes to improve the security performance of the three transmission links when the relay decodes the received data correctly . Otherwise, Cooperative jam ming strategy will be used to ensure secure transmission of the main link except the relay links.