Research On Multi-radio Channel Hopping Blind Rendezvous Technology

To overcome the challenges caused by heterogeneous spectrum and dynamic changes in spectrum resources,cognitive radio networks need to exchange various types of control information,including spectrum sensing results,clock information,network topology,and handshake negotiation,between neighboring nodes.In order to improve the efficiency and reliability of control information exchange,any two neighboring cognitive nodes can independently hop on the same authorized channel set according to the locally generated channel hopping sequence,and achieve blind rendezvous and exchange control information when accessing the same authorized channel at the same time.The main advantages of the control information exchange mechanism based on channel hopping blind rendezvous include that it does not depend on any fixed and preset control channels,has strong anti-blocking interference ability,can effectively reduce the impact range of tracking interference,and effectively mitigate control channel traffic saturation.For this reason,this paper studies the design theory and generation algorithm of blind rendezvous channel hopping sequences for clock asynchronous cognitive radio network nodes.It minimizes the longest time interval between two consecutive blind rendezvous(ie,MTTR and MCTTR)of neighboring cognitive nodes as much as possible with or without the interference of authorized users.In particular,when all cognitive nodes have the same number of antennas,through strict analysis and derivation,this paper proves the MTTR theoretical lower bound of blind rendezvous of any two cognitive nodes in the presence of authorized user interference.Based on the mathematical theory of relaxed cyclic difference set,we proposed a channel hopping sequence generation algorithm that can effectively approximate the lower bound of the theory we proved and shorten MTTR.On the other hand,for cognitive radio networks where different cognitive nodes may have different numbers of antennas,a blind rendezvous channel hopping sequence generation algorithm that is backward compatible with single antenna cognitive nodes is designed based on the difference set theory.Make full use of the antenna resources of each cognitive node to achieve blind channel hopping rendezvous.The numerical simulation comparison based on MATLAB shows that compared with the existing blind rendezvous channel hopping sequence that applicable to cognitive nodes with the same number of antennas,the channel hopping sequence proposed in this paper can obtain smaller MTTR and MCTTR values at the same time,thus the better blind channel hopping rendzvous performance can obtained with or without the interference of authorized users.Compared with the existing blind rendezvous channel hopping sequence that applicable to cognitive nodes may have different numbers of antennas,the channel hopping sequence proposed in this paper can also obtain a smaller MTTR value,thereby obtaining better interference-free blind channel hopping renezvous performance.