Method and apparatus for improving the apparent accuracy of a data receiver clock circuit

摘要

The apparent accuracy of a clock circuit (20) used to recover timing and transmitted information signals in a data receiver is improved. A timing relationship inherent in a received signal (10) is detected (34, 40) prior to the acquisition of a timing component embedded (16) in a desired information portion of the received signal. The timing relationship has an accuracy that is greater than the accuracy of the clock circuit (20). The clock circuit (20) is controlled in response to the timing relationship to operate with an improved range of accuracy. Thereafter, the embedded timing component is acquired and used to control the clock circuit. In an illustrated embodiment, the timing relationship is derived from a symbol rate (40) of the received signal. In an alternate embodiment, the timing relationship is obtained from a separate transmitted reference signal (34), such as a transmitted television signal.