Non-coherent frequency shift keying detection scheme

A method using a capture circuit for receiving and decoding an incoming frequency shift keying (FSK) data signal, comprising the steps of:

• receiving a FSK sampled signal;
• outputting FSK zero crossing event signals;
• measuring a period between said FSK zero crossing event signals;
• generating a decoded signal indicative of value of said FSK data signal;
• and
• performing a self alignment to ensure that the sampling of said decoded signal corresponds to the middle of the baud;
• detecting the presence of caller ID signal;
• receiving an incoming analog caller ID FSK symbol;
• initiating operation of said capture circuit;
• passing information in an incoming analog FSK caller ID data signal inherent within incoming telephone call through as an output.

A caller ID capture circuit utilizing frequency shift keying (FSK) principles for receiving and decoding an incoming caller ID data signal for use by a computer comprising:

• a caller ID detector circuit coupled to receive an incoming telephone call, detect presence of caller ID signal therefrom and thereupon initiate operation of said caller ID capture circuit and further to pass on information from an incoming analog FSK caller ID data signal inherent within said incoming telephone call through as an output;
• a zero crossing detector circuit that receives a binary FSK caller ID sampled signal and outputs a FSK zero crossing event signal;
• a zero crossing counter circuit coupled to said zero crossing detector circuit, wherein said zero crossing counter circuit measures the period between said FSK zero crossing event signals and outputs a zero crossing signal indicative of the binary value of said caller ID data signal;
• a state variable circuit coupled to said zero crossing counter circuit and said zero crossing detector circuit, for outputting binary data equivalent to said information contained within said analog FSK caller ID data signal;
• and
• a state counter circuit that automatically performs a self alignment to ensure that the sampling of output of said state variable circuit occurs in the middle of each cycle, wherein said state variable circuit utilizes a frequency period threshold to automatically accommodate multiple industry standard modem data transmission protocols based on frequency shift keying and wherein said analog FSK caller ID data signal complies with either of the V.23 standard or the Bell 202 standards.

A caller ID capture circuit utilizing frequency shift keying (FSK) principles for receiving and decoding an incoming caller ID data signal for use by a computer comprising:

• a zero crossing detector circuit that receives a binary FSK caller ID sampled signal and outputs a FSK zero crossing event signal;
• a zero crossing counter circuit coupled to said zero crossing detector circuit, wherein said zero crossing counter circuit measures the period between said FSK zero crossing event signals and outputs a zero crossing signal indicative of the binary value of said caller ID data signal;
• a state variable circuit coupled to said zero crossing counter circuit and said zero crossing detector circuit, for outputting binary data equivalent to information contained within said incoming caller ID data signal;
• a state counter circuit that automatically performs a self alignment to ensure that the sampling of output of said state variable circuit occurs in the middle of each cycle, wherein said state variable circuit utilizes a frequency period threshold to automatically accommodate multiple industry standard modem data transmission protocols based on frequency shift keying and wherein said incoming caller ID data signal complies with either of the V.23 standard or the Bell 202 standards;
• a caller ID detector circuit coupled to receive an incoming telephone call including an incoming analog FSK caller ID data signal;
• and
• a threshold detector circuit coupled to said caller ID detector circuit and wherein said threshold level detector circuit rectifies said incoming analog FSK caller ID data signal thus providing a rectified FSK caller ID data signal.

A caller ID capture circuit utilizing frequency shift keying (FSK) principles for receiving and decoding an incoming caller ID data signal for use by a computer comprising:

• a caller ID detector circuit coupled to receive an incoming telephone call including an incoming analog FSK caller ID data signal;
• a threshold detector circuit coupled to said caller ID detector circuit and wherein said threshold detector circuit rectifies said incoming analog FSK caller ID data signal thus providing a rectified FSK caller ID data signal;
• a sampling circuit coupled to said threshold detector circuit wherein said sampling circuit receives and samples said rectified FSK caller ID data signal and thereupon provides a binary FSK caller ID sampled signal;
• a zero crossing detector circuit that receives said binary FSK caller ID sampled signal and outputs a FSK zero crossing event signal;
• a zero crossing counter circuit coupled to said zero crossing detector circuit, wherein said zero crossing counter circuit measures the period between said FSK zero crossing event signals and outputs a zero crossing time signal indicative of the binary value of said caller ID data signal;
• a state variable circuit coupled to said zero crossing counter circuit and said zero crossing detector circuit, for outputting binary data equivalent to information contained within said analog FSK caller ID data signal;
• and
• a state counter circuit that automatically performs a self alignment to ensure that the sampling of output of said state variable circuit occurs in the middle of each cycle, wherein said state variable circuit utilizes a frequency period threshold to automatically accommodate multiple industry standard modem data transmission protocols based on frequency shift keying and wherein said analog FSK caller ID data signal complies with either of the V.23 standard or the Bell 202 standards.