Patent ID: 7830953

Claim:
A receiving apparatus for sampling and receiving a transmitting signal transmitted based on a communication system for exchanging information with an intermittent pulse train signal in a nominal pulse repetition frequency or an integer times thereof, the receiving apparatus comprising: an initial synchronization acquiring device for synchronizing a sampling timing of a receiving signal to a pulse location or a pulse phase before demodulation of the receiving signal, wherein the initial synchronization acquiring device comprises a peak search function for holding a largest output value as a peak value by searching all phases corresponding to the frequency of the transmitting signal with a first search resolution, judging existence of the receiving signal from the peak value, and estimating a new peak phase estimated region from a phase region including phase of the peak value and being narrower than the all phases when the receiving signal exists; and a detailed synchronization acquiring function for searching, in a second search resolution, the new peak estimated region estimated with the peak search function, wherein the peak search function repeats a plurality of times of the processes for holding the largest output value as a peak value by searching all phases of the new peak phase estimated region with the first search resolution or a search resolution higher than the first search resolution and moreover estimating the new peak phase estimated region from the phase region including the phase of the peak value and being narrower than the peak phase estimated region, and wherein the peak search function repeats the processes until the peak phase estimated region becomes equal to or narrower than a pulse width TW of the transmitting signal.