Abstract:

Doppler frequency shift has an important influence on modern spread spectrum communication systems, and correlations with time delay and Doppler frequency shift should be considered when designing frequency hopping sequence (FHS). The theoretical limit to time-frequency two-dimensional (2D) Hamming correlation of FHS is studied. The time-frequency 2D Hamming correlation of Cai FHS sets is calculated. Under the guidance of the theoretic bound, the 2D Hamming correlations of Cai FHS sets are discussed and some optimal FHSs are obtained. Finally, the 2D Hamming correlations of polynomial FHS sets are analyzed.