The Design And Analysis Of Optimal Frequency Hopping Sequence Set With Low Hit Zone

Frequency hopping communication originated from military radio communication.It has good anti-interference and multi-address networking,which can make military communication unimpeded in the harsh electromagnetic environment.Due to the excellent characteristics of frequency hopping communication,it also occupies a wide application market in civil communication systems.The frequency hopping communication system is one of the extended spectrum communication methods.The constant frequency hopping ensures that the system has excellent anti-interference ability,thus ensuring the safety and reliability of the communication system.The orthogonality of the frequency hopping sequence enables the system to have multiple access communication capabilities to achieve spectrum resource sharing.Compared with traditional communication methods,frequency hopping communication also has a low probability of interception,strong anti-fading capability,and is more compatible with narrowband communication systems.The research content of frequency hopping communication system mainly includes two aspects: one is to find the theoretical limit of designing the hopping sequence;the other is to design and construct the hopping sequence set that satisfies or almost satisfies the optimal theory.In the frequency hopping communication system,the performance of the hopping sequence directly determines the performance of the communication system,that is,if the performance of the hopping sequence is poor,even if the hardware circuit support of the frequency hopping communication system is excellent,it is impossible to achieve Anti-interference ability indicators required by the system.Therefore,finding and designing frequency hopping sequences or frequency hopping sequence sets with excellent performance is an important part of researching frequency hopping communication systems.In practical applications,as the number of communication users increases substantially,communication requirements continue to increase,and the number of sequences of frequency hopping sequences constructed according to conventional methods is far insufficient to meet system requirements.In order to solve this problem,research scholars have proposed to reduce the range of Hamming correlation values of sequences from a whole period to a small range near zero delay based on a quasi-synchronous communication system,and construct a satisfying condition under certain conditions.The sequence set of good properties,the concept of low hit zone is thus produced.The concept of low hit zone was proposed by professor Fan Pingzhi in 2003.The main research of this paper is to find out the construction methods of several new types of optimal low hit zone frequency hopping sequence sets,and obtain some hopping sequence sets with large sequence numbers.The main research contents of this paper are as follows:1)Based on the Chinese remainder theorem,used the existing sets of conventional frequency hopping sequences,a large number of hopping sequence sets with low hit zone properties are constructed,and it is proved that the sequence set is an optimal frequency hopping sequence set with low hit zone where the set satisfies Peng-Fan-Lee theory.2)Using the existing frequency hopping sequence set with low hit zone as the original sequence set and the OC sequence set as the extension factor,the two-dimensional extended construction method of the frequency hopping sequence set with low hit zone is given.This construction method is based on Cartesian product and interleaving technique.The resulting sequence set is the optimal frequency hopping sequence set with low hit zone that meets Peng-Fan-Lee theory.The extended sequence length is longer and the frequency gap is extended.The set is larger and the number of sequences is larger,and the largest Hamming correlation value of the sequence set in the low hit zone is consistent with the maximum Hamming correlation value of the base sequence set.3)There is a shift equivalence between the resulting sequences obtained by the general extended construction method,that is,the Hamming correlation of the hopping sequence outside the low hit zone will occur.To this end,this paper presents a construction method of low hit zone frequency hopping sequence set with cyclic shift inequality.It is mainly to construct a low hit zone frequency hopping sequence set with inequivalent cyclic shift by using a set of shifted sequences with non-equivalent properties,and the sequence set is optimal for the Peng-Fan-Lee boundary.