Research on the synchronization scheme of a cognitive asynchronous frequency-hopping communication system
Nan Chen · Journal of Xidian University · 2009
A synchronization scheme for a cognitive asynchronous frequency-hopping communication system(CAFHCS) is proposed.There are two optional frequency-hopping patterns in this scheme.In transmiting information in the current hop,the status of the two frequency points which are calculated by the two patterns for the next hop are sensed simultaneously.The transmitter selects the frequency point for the next hop adaptively according to the sensing results,which improves the anti-jamming performance of the asynchronous frequency-hopping communication system(AFHCS).It is observed from simulation results that the users' capacity of the CAFHCS increases over 6 times compared with that of the AFHCS when the probability of synchronization is above 95%.By introducing the cyclic prefix to a hop signal,the frequency-hopping pattern recognition is implemented adaptively at the receiver,and the difficult problem of bit synchronization of the frequency-hopping signal is solved as well.Furthermore,the performance analysis of the synchronization scheme for AFHCS and CAFHCS are given.