Standard frequency and timing generator and generation method thereof

A standard frequency and timing generator for generating a high accuracy standard frequency signal and a timing signal, comprising:

• a voltage controlled crystal oscillator (VCXO) for generating a high stability oscillation frequency to be used as a standard frequency and timing signal;
• a radio wave receiver which receives a radio wave which includes a high accuracy reference time signal and reproduces said reference time signal to be used as a reference to a phase lock loop for phase locking said oscillation frequency of said VCXO;
• a time interval measuring circuit which measures a time interval which is a phase difference between said reference time signal and a time signal derived from said oscillation frequency of said VCXO and generates data indicating said phase difference;
• a frequency control processor which arithmetically determines control data based on said phase difference data from said time interval measuring circuit such that said phase difference maintains a constant value by a phase lock loop;
• a frequency deviation data generator for averaging and compiling said phase difference data with a predetermined sequence to obtain frequency deviation trend data of said VCXO;
• a curve-fit compensation data generator for generating compensation data based on said frequency deviation trend data from said frequency deviation data generator by applying a Wavelet transform process to compensate curve like frequency changes in a free running oscillation state of said VCXO when said reference time signal is unavailable for said phase lock loop;
• a reference signal detector for generating a detection signal when said reference time signal is unavailable from said radio wave receiver for said phase lock loop;
• and
• a D/A converter which converts said control data from said frequency control processor and said compensation data from said compensation data generator to an analog voltage to be provided to said VCXO.

A method of generating a high accuracy standard frequency signal and a timing signal, comprising the following steps of:

• providing a voltage controlled crystal oscillator (VCXO) for generating a high stability oscillation frequency to be used as a standard frequency and timing signal;
• receiving a radio wave which includes a high accuracy reference time signal and reproducing said reference time signal;
• detecting a phase difference between said reference time signal and a time signal derived from said oscillation frequency of said VCXO and generating data indicating said phase difference;
• forming a phase lock loop for phase locking said oscillation frequency of said VCXO to said reference time signal by sending a control data based on said phase difference data;
• collecting said phase difference data with a predetermined sequence to obtain frequency deviation trend data of said VCXO;
• generating curve-fit compensation data based on said frequency deviation trend data by applying a Wavelet transform process to compensate frequency changes in a free running oscillation state of said VCXO when said reference time signal is unavailable for said phase lock loop;
• generating a detection signal when said reference time signal is unavailable from said radio wave for said phase lock loop;
• and
• converting said compensation data to an analog voltage and applying said analog voltage to said VCXO when said reference time signal is unavailable.

A standard frequency and timing generator for generating a high accuracy standard frequency and timing signal, comprising:

• (a) a first frequency and timing generator comprising:
• a first receiver unit having a first satellite wave receiver for extracting a reference time signal from a radio wave signal;
• a first standard frequency generator unit having a first standard frequency generator;
• a first output unit having a first output circuit;
• (b) a second frequency and timing generator comprising:
• a second receiver unit having a second satellite wave receiver for extracting said reference time signal from said radio wave signal;
• a second standard frequency generator unit having a second standard frequency generator;
• a second output unit having a second output circuit;
• (c) a power divider for receiving said radio wave signal and distributing said radio wave signal to said first and second receiver units;
• (d) an output terminal for providing a standard frequency and timing signal to an external system therefrom;
• (e) switch means for selecting one of two counterpart units to send a signal from the selected unit to the units of later stages.
• (e) a controller for receiving defect detection signals from each of said units and sending a control signal to said switch means to establish signal flows in said units toward said output terminal.

A standard frequency and timing generator for generating a high accuracy standard frequency and timing signal, comprising:

• (a) a first frequency and timing generator comprising:
• a first receiver unit having a first satellite wave receiver for extracting a reference time signal from a radio wave signal;
• a first standard frequency generator unit having a first standard frequency generator and a first input switch;
• a first output unit having a first intermediate switch, a first output circuit, and a first output switch;
• (b) a second frequency and timing generator comprising:
• a second receiver unit having a second satellite wave receiver for extracting said reference time signal from said radio wave signal;
• a second standard frequency generator unit having a second standard frequency generator and a second input switch;
• a second output unit having a second intermediate switch, a second output circuit, and a second output switch;
• (c) a power divider for receiving said radio wave signal and distributing said radio wave signal to said first and second receiver units;
• (d) an output terminal for providing a standard frequency and timing signal to an external system therefrom;
• and
• (e) a controller for receiving defect detection signals from each of said units and sending a control signal to said switches to select signal flows in said units toward said output terminal;
• wherein said first and second input switches select either one of signals from said first and second receiver units, and said first and second intermediate switches select either one of signals from said first and second standard frequency generator units, and said first and second output switches select either one of signals from said first and second output circuits.