| 摘要 |
<p>A frequency control circuit (350), and associated method (700), for a receiver operative to receive a TDMA signal transmitted by a transmitter in a TDMA communication system. A first frequency detector (452) generates a first frequency control signal (468). A second frequency detector, comprised of a portion of a decision-directed demodulator (450), generates a second frequency control signal (496). The first frequency control signal (468) is utilized to effectuate frequency control when a signal is continuously received by the receiver, such as times immediately subsequent to initial powering of the receiver as the receiver becomes synchronized with the TDMA signal transmitted thereto. Once a receiver becomes synchronized to the transmitter, the receiver needs only be powered during intermittent time periods when the TDMA signal is transmitted to the receiver. The second frequency control signal (496) is utilized to effectuate frequency control only after the receiver is synchronized with the transmitter to permit intermittent operation of the receiver, and the frequency differences between the signal transmitted to the receiver and a receiver-oscillator oscillation frequency is less than a maximum level.</p> |
