Patent ID: 7460147

Claim:
An interference detecting circuit for detecting interference of a digital signal, which is capable of being divided into a plurality of fields, each field including at least a first synchronization format data and a second synchronization format data, the first and second synchronization format data respectively including a plurality of sync symbols, and the interference detecting circuit comprising: a buffering module for delaying the first synchronization format data when receiving the first synchronization format data; a correlation arithmetic circuit coupled to the buffering module for receiving the digital signal and performing a correlation operation on the second synchronization format data and the delayed first synchronization format data to output a detection signal when receiving the second synchronization format data; a time control circuit for generating a first control signal when receiving the first synchronization format data; a logic control circuit coupled to the time control circuit and the correlation arithmetic circuit for generating a third control signal according to the first control signal to control the correlation arithmetic circuit; and a determining circuit for determining whether or not to perform interference rejection on the digital signal according to the result of the correlation operation.