| CPC H04B 1/709 (2013.01) [H04W 52/367 (2013.01); H04B 2001/6912 (2013.01)] | 14 Claims |
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1. A receiver comprising:
a correlation value calculator to calculate a first cross-correlation function between a received signal and an up chirp and calculate a second cross-correlation function between the received signal and a down chirp, the received signal being a signal transmitted from a transmitter and having a preamble spread with the up chirp that is a spread code whose frequency increases with time and the down chirp that is a spread code whose frequency decreases with time;
a power value calculator to calculate first power values of the first cross-correlation function and calculate second power values of the second cross-correlation function;
a correlation power memory to store the first power values and the second power values at each sample timing for one period of the spread code;
determination circuitry to determine a first estimated timing for the up chirp from the first power values for one period of the spread code, and determine a second estimated timing for the down chirp from the second power values for one period of the spread code; and
an estimator to estimate a spread code timing of the transmitter using the first estimated timing and the second estimated timing, and perform coarse estimation of a frequency offset with respect to the transmitter.
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