Research On Construction Of Time-Frequency Frequency Hopping Sequence With No Hit Zone And Low Hit Zone

Frequency hopping(FH) communication is an important kind of spread spectrum communication technology in which spread spectrum sequence is frequency hopping sequence. The performance of anti-multiple access interference and anti-multipath interference in the frequency hopping code division multiple access(FH-CDMA)communication system depends on hamming correlation properties of frequency hopping sequence. No hit zone(NHZ) and Low hit zone(LHZ) frequency hopping sequences have ideal Hamming correlation properties in the relevant area. According to the characteristics,the quasi synchronous FH-CDMA system which is based on NHZ/LHZ frequency hopping sequence can eliminate or reduce the multiple access interference. In this paper,author studied the construction methods about the time-frequency frequency hopping sequence set with no hit zone、the theory bound of the time-frequency frequency hopping sequence set with low hit zone、the design and performance analysis of the time-frequency frequency hopping sequence set with low hit zone.Firstly, existing frequency hopping sequences with no hit zone are expanded to two-dimensional time-frequency frequency hopping sequences with no hit zone. At the same time, the theoretical bound and two construction methods of time-frequency frequency hopping sequences with no hit zone are introduced.Secondly, existing frequency hopping sequences with low hit zone are expanded to two-dimensional time-frequency frequency hopping sequences with low hit zone. The basic concepts of two-dimensional time-frequency frequency hopping sequences with low hit zone are put forward. Using the mathematical proof, author also establishes the theoretical bounds on the maximum periodic Hamming correlation, the maximum periodic partial Hamming correlation and the average periodic partial Hamming correlation of two-dimensional time-frequency frequency hopping sequences with low hit zone.Finally, based on Welch Costas sequence and Golomb Costas sequence, a kind of time-frequency frequency hopping sequence sets with low hit zone is constructed by cyclic shift method. The frequency hopping sequence sets satisfy the theoretical boundwhich is formed by two-dimensional periodic Hamming auto-correlation and cross-correlation function of frequency hopping sequence and can obtain ideal Hamming auto-correlation and cross-correlation properties in the two-dimensional time-frequency low hit zone.