Patent ID: 6226505
Filing Date: 2001-05-01
Classification: H03J,H04L

Abstract:
A frequency correction apparatus for a radio calling system, comprising:first and second reception means for receiving call signals comprising frames, each of said frames comprising a frame synchronization portion and a data portion;first and second local oscillation means for generating local oscillation frequencies for converting said call signals received by said first and second reception means into intermediate frequencies;demodulation means for demodulating the intermediate frequencies;frequency correction means for correcting the local oscillation frequencies of said first and second local oscillation means on the basis of frequencies of the frame synchronization portions of demodulated signals output from said demodulation means;timing detection means for outputting a correction timing signal for execution of correction based on the demodulated signals output from said demodulation means, and a signal indicating a signal reception ratio of each of said first and second reception means; anddetermination means for determining one of said first and second reception means exhibiting a highest signal reception ratio on the basis of the signal indicating the signal reception ratio.