Research On Construction Of Two-dimensional Frequency Hopping Sequence With Periodic No Hit Zone And Aperiodic Low Hit Zone

Frequency Hopping(FH)Communication is an important spread spectrum communication technique by controlling frequency hopping to realize spectrum spreading.The Hamming correlation performance of the frequency hopping sequence reflects the number of collisions between frequency hopping sequences.But also greatly determines the performance of frequency hopping code division multiple access(FH-CDMA)communication system.The No Hit Zone(NHZ)and the Low Hit Zone(LHZ)hopping sequence set have excellent Hamming correlation in a certain correlation zone.According to this characteristic,based on NHZ/LHZ frequency hopping sequence of quasi-synchronous FH-CDMA system can be used to eliminate or reduce interference,thereby improving system performance.In this paper,author studied the theoretical bound and design of the time-frequency two-dimensional frequency hopping sequence with no hit zone,the theoretical bound of time-frequency two-dimensional aperiodic frequency hopping sequence with low hit zone and construction of time-frequency two-dimensional aperiodic frequency hopping sequences with low hit zone and its performance analysis.Firstly,existing one-dimensional frequency hopping sequence with no hit zone are extended to the time-frequency two-dimensional frequency hopping sequence with no hit zone,introduce and discuss the theoretical boundary of the time-frequency two-dimensional frequency hopping sequence with no hit zone,proves the equivalence conditions of these theoretical bounds and gives two kinds of construction methods.Secondly,existing one-dimensional aperiodic frequency hopping sequence with low hit zone are extended to the time-frequency two-dimensional aperiodic frequency hopping with low hit zone.The basic concept of frequency-hopping two-dimensional aperiodic frequency hopping sequence with low hit zone are put forward.This paper uses the mathematical method to derive the basic Hamming correlation properties,and establishes the theoretical bounds on the maximum aperiodic Hamming correlation of time-frequency two-dimensional frequency hopping sequence with low hit zone.Finally,based on the Welch Costas sequence and the Golomb Costas sequence,a setof time-frequency two-dimensional aperiodic frequency hopping sequences with low hit zone is constructed.The frequency hopping sequence set satisfies the theoretical bound of the frequency hopping sequence set of the low hit zone frequency region in the two-dimensional time-frequency domain.The auto-correlation and cross-correlation characteristics are excellent in the low hit zone.