Symbol timing recovery apparatus

Abstract

A symbol timing recovery apparatus recovers the symbol timing necessary for sampling a signal received in a receiver of a high-speed data transmission system such as a full-digital high-definition television. Pre-processing filters primarily determine a signal component necessary for recovering the symbol timing from the received signal. Square calculators, respectively corresponding to an I-channel and a Q-channel, square the outputs of the pre-processing filters. An adder adds the outputs of the square calculators. A narrow-band filter performs narrow-band filtering having a center frequency which matches a symbol rate with respect to the output of the adder. An average value detector calculates an average value of the positive-going zero-crossing point and determines a sampling point in time and a symbol timing interval. A clock generator uses the sampling point in time and the symbol timing interval and generates a sampling clock which is appropriate for an input signal. Thus, the symbol timing recovery apparatus can perform speedier and more exact symbol timing recovery.

Dependencies are inferred from the claim text.