Research On The Optimal Low Hit Zone Frequency Hopping Sequence Sets

With the progress of the times and the continuous development of science technology,people’s communication requirements are becoming more and more higher.Frequency hopping multiple access spread spectrum system is widely used in Bluetooth,military radio communication,mobile communication,modern radar and sonar echo location system because of its anti-jamming,security and multi-access.Typically in a code division multiple access environment,there is always a desire to keep the mutual interference between the transmitters at the same frequency point,they are prone to interfere with each other,and the degree of mutual interference is closely connected with the Hamming correlation of used frequency hopping(FH)sequences.Therefore,it is important to design FH sequences with good Hamming correlation characteristics.In 2003,Southwest Jiaotong University Ye Wenxia and Fan Pingzhi et al.For the first time put forward the concept of low hit zone / zero hit zone(Low Hit Zone/Zero Hit Zone,LHZ/NHZ)frequency hopping sequence,the concept is applied to quasi-synchronous communication systems,the size of the Hamming correlation value of the LHZ/NHZ frequency hopping sequence is of great significance for the ability of the quasi-synchronization communication system to protect against multiple access interference.Therefore,the design of LHZ/NHZ frequency hopping sequence set is one of the most important contents of frequency hopping communication.In this thesis,we propose a class of optimal low frequency hopping sequences with new parameters based on the interleaving technique.For a given frequency hopping sequence,a set of frequency hopping sequences with different parameters can be constructed by altering based sequence sets and selecting the appropriate shift sequence sets,The new sequence sets is optimal for the Hamming correlation theory of LHZ/NHZ frequency hopping sequences.In this thesis,we mainly study the designing of optimal low hit zone frequency hopping sequences sets.(1)Analysing of the theory of constraints between the parameters of frequency hopping sequence sets can be satisfied.The frequency hopping sequence theory mainly contains the following parameters: the number of frequency gap sets,the sequence length of frequency hopping sequences,the number of sequences of frequency hopping sequences,the low hit zone and Hamming correlation of FH sequences,The general theoretical bound for frequency hopping sequences is presented.Including the conventional frequency hopping sequence maximum Hamming correlation function and its theory,the average Hamming correlation function and its theory,partial Hamming correlation function and its theory and low hit zone frequency hopping sequences sets of the maximum Hamming correlation function and its theory,the average Hamming correlation function and its theory,and the partial Hammingcorrelation function and its theory,the constraint relation between the parameters in the optimal case is analyzed.These theoretical bounds parameter diagrams provide guidance for the construction of frequency hopping sequences.(2)This thesis used the theory of interleaving structure of frequency hopping sequences is introduced,the research and analysis of the approach for constructing optimal low hit zone frequency hopping sequences sets based on interleaving,technique,the sequence parameter constraint analysis and performance analysis are also given.(3)This thesis studies the construction of optimal low hit zone frequency hopping sequences sets based on interleaving method,through the research and analysis of the interleaving technique,a new method is proposed,which is improving the previous one,The new sequence set has a new parameter and achieves the optimal function of the periodic Hamming correlation function.In addition,sequence parameter comparison,construction example and performance analysis are given.(4)It summarizes the work of this thesis and prospects the future work.