| 摘要 |
<p>PURPOSE: To improve the precision of synchronism of the period of sampling timing by controlling the sampling timing period of a receiver and the frequency of a local oscillator for frequency conversion thus eliminating the frequency deviation and the period deviation. CONSTITUTION: When the receiver receives a pilot signal, switches 18a and 18b are connected to a multiplier 19 to multiply the window function generated by a window function generator 20. An output gn from the multiplier 19 is inputted to a serial-parallel converter 21, and the output is subjected to discrete Fourier transformation by a fast Fourier transformer 22. Then, a discrete Fourier transformation output Gk of the pilot signal has the peak of the output absolute value in a prescribed frequency index, and this pattern is stored in the memory in a transmission frequency pattern Wi generator 24. There may be probability that the timing synchronism deviation is sufficiently small but the frequency deviation of the local oscillator for frequency conversion is large. Therefore, the period deviation is roughly estimated, and correlations between the pattern Wi and the transformer 23 are taken to perform search only in a prescribed range.</p> |
