Interference detecting circuit utilizing synchronization symbols and method thereof

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;
• 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, comprising:
• a first filter coupled to the correlation arithmetic circuit for performing interference rejection filtering on the detection signal to output a first filtered signal;
• a first interference detection module coupled to the first filter for generating a first processing signal according to the first filtered signal, wherein the first processing signal corresponds to the interference in the first filtered signal;
• a second interference detection module coupled to the correlation arithmetic circuit for generating a second processing signal according to the detection signal, wherein the second processing signal corresponds to the interference in the detection signal;
• a comparison circuit coupled to the first and second interference detection modules for comparing the first and second processing signals and generating a selection signal according to the comparison result of the first and second processing signals;
• a second filter for performing interference rejection filtering on the digital signal to output a second filtered signal;
• and
• a multiplexer coupled to the second filter and the comparison circuit for multiplexing the digital signal or the second filtered signal according to the selection signal.

An interference detecting method 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 method comprising:

• delaying the first synchronization format data when receiving the first synchronization format data;
• 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;
• generating a first control signal when receiving the first synchronization format data;
• generating a third control signal according to the first control signal;
• passing the detection signal with respect to the third control signal;
• and
• determining whether or not to perform interference rejection on the digital signal according to the result of the correlation operation.

An interference detecting method 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 method comprising:

• delaying the first synchronization format data when receiving the first synchronization format data;
• 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;
• and
• determining whether or not to perform interference rejection on the digital signal according to the result of the correlation operation, comprising:
• performing interference rejection filtering on the detection signal to output a first filtered signal;
• performing interference detection processing on the first filtered signal to generate a first processing signal, wherein the first processing signal corresponds to the interference in the first filtered signal;
• performing interference detection processing on the detection signal to generate a second processing signal, wherein the second processing signal corresponds to the interference in the detection signal;
• comparing the first and second processing signals and generating a selection signal according to the comparison result of the first and second processing signals;
• performing interference rejection filtering on the digital signal to output a second filtered signal;
• and
• multiplexing the digital signal or the second filtered signal according to the selection signal.

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;
• an 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 control circuit for generating a control signal in response to the digital signal;
• a switch, coupled to the control circuit, for passing the detection signal according to the control signal;
• a determining circuit for determining whether or not to perform interference rejection on the digital signal according to the detection signal;
• a filtering circuit for filtering the digital signal and thereby generating a filtered signal;
• and
• an output circuit, coupled to the determining circuit, for outputting the digital signal or the filtered signal in accordance with a determining result of the determining circuit.

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;
• an 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 first processing circuit for generating a first processing signal according to the detection signal;
• a second processing circuit for generating a second processing signal according to the detection signal;
• a selection circuit, coupled to the first and second processing circuits, for generating a selection signal according to the first and second processing signals;
• a filtering circuit for filtering the digital signal and thereby generating a filtered signal;
• and
• an output circuit, coupled to the selection circuit, for outputting the digital signal or the filtered signal in accordance with the selection signal.