On initial acquisition of FH/TH Spread Spectrum signal

This paper presents a digital acquisition scheme for the initial acquisition of frequency and time-hopped signals employing sequences generated by linear feedback shift registers (LSFR). The received signal is modeled by an autoregressive (AR) process. The parameters of the AR process are identified in terms of the corresponding partial correlation (PARCOR) coefficients. The presence of the signal during each signaling interval is detected and its frequency estimated using these identified parameters. This information is used to estimate the initial states of the LFSRs used in signal generation. This scheme is suitable for frequency-hopping time-hopping systems operating at medium signal-to-noise ratios.