A frequency correction apparatus for a radio calling system includes reception antennas, local oscillation sections, demodulation sections, and a correction control section. The reception antennas receive call signals constituted by frames as units, each constituted by a frame synchronization portion...http://www.google.com.hk/patents/US6226505?utm_source=gb-gplus-share專利 US6226505 - Automatic frequency correction apparatus and method for radio calling system
