Time and Frequency Staggered Search for BOC Modulated Ranging Signals

This paper tackles the problem of code acquisition for BOC modulated signals in the presence of timing and frequency uncertainty. Considering a discretization of the timing uncertainty domain in time slots, and of the frequency uncertainty domain in frequency bins, we introduce a search strategy, identified as Staggered Time and Frequency Search, coupled to a joint controlled single dwell Threshold Crossing criterion in both domains. Differently from conventional techniques, this method does not require any parallelism, but digital control of the sampler and the oscillator to scan different hypotheses in time and frequency until the acquisition is completed. According to the analytical and simulated results shown in this paper, this novel approach achieves performance close to that of classical techniques, with significant complexity and power consumption reduction.