Patent attributes
An OFDM receiver (1) is provided which includes a clock-frequency error calculation circuit (41) to calculate a difference in clock frequency between a clock for a received signal and an operation clock used in the receiver (1), and a guard correlation/peak detection circuit (12) to determine an autocorrelation of a guard interval and detect a peak timing of the correlation signal. The guard correlation/peak detection circuit (12) incorporates a free-running counter, and outputs a count of the free-running counter at the peak timing to the clock-frequency error calculation circuit (41). The clock-frequency error calculation circuit (41) uses a plurality of time-change rate detection circuits provided at different time intervals to calculate a time-change rate of an input count. The clock-frequency error calculation circuit (41) plots the time-change rates to generate a histogram and calculates a clock-frequency error from the histogram.
