Doppler learning phase lock loop for burst demodulator

A demodulator which demodulates burst communications comprising:

• a phase angle source, coupled to a current received burst communication, which provides a phase angle of the current received burst communication;
• a comparator, coupled to the phase angle source and a source of an estimated phase angle, which provides an output signal representing an angular difference between a phase of the current received burst communication and the estimated phase angle;
• and
• a phase lock loop, coupled to the output signal, which provides the estimated phase angle including a phase accumulator which provides a first order component of compensation in the estimated phase angle and a burst frequency accumulator which provides a second order component of compensation in the estimated phase angle;
• and wherein
• the phase lock loop includes a Doppler accumulator which provides a Doppler output which provides another second order component of compensation in the estimated phase angle for the Doppler effect produced by relative motion between the demodulator and a source of the burst communications.

A demodulator which demodulates burst communications comprising:

• a phase angle source, coupled to a current received burst communication, which provides a phase angle of the current received burst communication;
• a comparator, coupled to the phase angle source and a source of an estimated phase angle, which provides an output signal representing an angular difference between a phase of the current received burst communication and the estimated phase angle;
• and
• a phase lock loop, coupled to the output signal, which provides the estimated phase angle;
• wherein the phase lock loop includes a Doppler accumulator which provides a Doppler output which provides compensation in the estimated phase angle for the Doppler effect produced by relative motion between the demodulator and a source of the burst communications;
• and wherein the Doppler accumulator continuously accumulates Doppler variations caused by the relative motion and provides compensation in the estimated phase angle which is not reset upon reception of each received burst communication.

A demodulator which demodulates burst communications comprising:

• a phase angle source, coupled to a current received burst communication, which provides a phase angle of the current received burst communication;
• a comparator, coupled to the phase angle source and a source of an estimated phase angle, which provides an output signal representing an angular difference between a phase of the current received burst communication and the estimated phase angle;
• and
• a phase lock loop, coupled to the output signal, which provides the estimated phase angle;
• wherein the phase lock loop includes a Doppler accumulator which provides a Doppler output which provides compensation in the estimated phase angle for the Doppler effect produced by relative motion between the demodulator and a source of the burst communications;
• and wherein the demodulator further comprises a storage register contained in the Doppler accumulator which, upon command, applies a known Doppler value as compensation in the estimated phase angle while disabling the Doppler output from providing compensation.

A demodulator which demodulates burst communications comprising:

• a phase angle source, coupled to a current received burst communication, which provides a phase angle of the current received burst communication;
• a comparator, coupled to the phase angle source and a source of an estimated phase angle, which provides an output signal representing an angular difference between a phase of the current received burst communication and the estimated phase angle;
• and
• a phase lock loop, coupled to the output signal, which provides the estimated phase angle;
• wherein the phase lock loop includes a Doppler accumulator which provides a Doppler output which provides compensation in the estimated phase angle for the Doppler effect produced by relative motion between the demodulator and a source of the burst communications;
• and wherein the demodulator further comprises a burst preamble processor, which is responsive to a burst input, to produce a gating signal;
• and
• a gate, coupled to the comparator and the Doppler accumulator, which passes a signal which is a function of the output signal from the comparator to the Doppler accumulator.

In a demodulator which demodulates burst communications including a phase angle source, a comparator coupled to the phase angle source and a source of an estimated phase angle and a phase lock loop, a method of receiving burst communications comprising:

• providing a phase angle from a phase angle source of a current received burst communication:
• providing from the comparator an output signal representing an angular difference between a phase of the current received burst communication and the estimated phase angle;
• and
• providing the estimated phase angle from the phase lock loop including a Doppler output which provides compensation in the estimated phase angle for the Doppler effect produced by relative motion between the demodulator and a source of the burst communications;
• and
• the phase lock loop comprises a phase accumulator which provides a first order component of compensation in the estimated phase angle and the Doppler accumulator provides a second order component of compensation in the estimated phase angle.

In a demodulator which demodulates burst communications including a phase angle source, a comparator coupled to the phase angle source and a source of an estimated phase angle and a phase lock loop, a method of receiving burst communications comprising:

• providing a phase angle from the phase angle source of a current received burst communication;
• providing from the comparator an output signal representing an angular difference between a phase of the current received burst communication and the estimated phase angle;
• and
• providing the estimated phase angle from the phase lock loop including a Doppler output which provides compensation in the estimated phase angle for the Doppler effect produced by relative motion between the demodulator and a source of the burst communications;
• wherein
• the phase lock loop comprises a phase accumulator which provides a first order component of compensation in the estimated phase angle and the Doppler accumulator provides a second order component of compensation in the estimated phase angle;
• and
• a burst frequency accumulator provides another second order compensation in the estimated phase angle.

In a demodulator which demodulates burst communications including a phase angle source, a comparator coupled to the phase angle source and a source of an estimated phase angle and a phase lock loop, a method of receiving burst communications comprising:

• providing a phase angle from the phase angle source of a current received burst communication;
• providing from the comparator an output signal representing an angular difference between a phase of the current received burst communication and the estimated phase angle;
• and
• providing the estimated phase angle from the phase lock loop including a Doppler output which provides compensation in the estimated phase angle for the Doppler effect produced by relative motion between the demodulator and a source of the burst communications;
• and wherein the Doppler accumulator continuously accumulates Doppler variations and provides compensation in the estimated phase angle which is not reset upon reception of each received burst communication.

In a demodulator which demodulates burst communications including a phase angle source, a comparator coupled to the phase angle source and a source of an estimated phase angle and a phase lock loop, a method of receiving burst communications comprising:

• providing a phase angle from the phase angle source of a current received burst communication;
• providing from the comparator an output signal representing an angular difference between a phase of the current received burst communication and the estimated phase angle;
• and
• providing the estimated phase angle from the phase lock loop including a Doppler output which provides compensation in the estimated phase angle for the Doppler effect produced by relative motion between the demodulator and a source of the burst communications;
• and wherein a storage register contained in the Doppler accumulator which, upon command, applies a known Doppler value as compensation in the estimated phase angle while disabling the Doppler output from providing compensation.

A demodulator which demodulates burst communications comprising:

• a phase angle source, coupled to a current received burst communication, which provides a phase angle of the current received burst communication;
• a comparator, coupled to the phase angle source and a source of an estimated phase angle, which provides an output signal representing an angular difference between a phase of the current received burst communication and the estimated phase angle;
• and
• a phase lock loop, coupled to the output signal, which provides the estimated phase angle including a phase accumulator which provides a first order component of compensation in the estimated phase angle;
• and wherein
• the phase lock loop includes a slowly varying common mode drift signal accumulator which provides a slowly varying common mode drift signal output which provides compensation in the estimated phase angle for an effect of the slowly varying common mode drift signal;
• and
• the slowly varying common mode drift signal accumulator provides a second order component of compensation in the estimated phase angle.

A demodulator which demodulates burst communications comprising:

• a phase angle source, coupled to a current received burst communication, which provides a phase angle of the current received burst communication;
• a comparator, coupled to the phase angle source and a source of an estimated phase angle, including a phase accumulator which provides a first order component of compensation in the estimated phase angle;
• and
• a phase lock loop, coupled to the output signal, which provides the estimated phase angle including a phase accumulator which provides a first order component of compensation in the estimated phase angle and a burst frequency accumulator which provides a second order component of compensation in the estimated phase angle;
• and wherein
• the phase lock loop includes a slowly varying common mode drift signal accumulator which provides a slowly varying common mode drift signal output which provides another second order compensation of compensation in the estimated phase angle for an effect of the slowly varying common mode drift signal.

In a demodulator which demodulates burst communications including a phase angle source, a comparator coupled to the phase angle source and a source of an estimated phase angle and a phase lock loop, a method of receiving burst communications comprising:

• providing a phase angle from a phase angle source of a current received burst communication;
• providing from the comparator an output signal representing an angular difference between a phase of the current received burst communication and the estimated phase angle;
• and
• providing the estimated phase angle from the phase lock loop including a slowly varying common mode drift signal output which provides compensation in the estimated phase angle for an effect of the slowly varying common mode drift signal;
• and
• the phase lock loop comprises a phase accumulator which provides a first order component of compensation in the estimated phase angle and a slowly varying common mode drift signal accumulator provides a second order component of compensation in the estimated phase angle.

In a demodulator which demodulates burst communications including a phase angle source, a comparator coupled to the phase angle source and a source of an estimated phase angle and a phase lock loop, a method of receiving burst communications comprising:

• providing a phase angle from the phase angle source of a current received burst communication;
• providing from the comparator an output signal representing an angular difference between a phase of the current received burst communication and the estimated phase angle;
• and
• providing the estimated phase angle from the phase lock loop including a slowly varying common mode drift signal output which provides compensation in the estimated phase angle for an effect of the slowly varying common mode drift signal;
• wherein
• the phase lock loop comprises a phase accumulator which provides a first order component of compensation in the estimated phase angle and a slowly varying common mode drift signal accumulator provides a second order component of compensation in the estimated phase angle;
• and
• a burst frequency accumulator provides another second order compensation in the estimated phase angle.