Circuit, use, and method for controlling a receiver circuit
A circuit, use, and method for controlling a receiver circuit is provided, wherein a complex baseband signal is generated from a received signal, a phase difference between a phase of the complex baseband signal and a phase precalculated from previous sampled values is determined, the phase difference is compared with a first threshold, a number is determined by counting the exceedances of the first threshold by the phase difference, a number of the counted exceedances is compared with a second threshold, and the receiver circuit is turned off if the number of counted exceedances exceeds the second threshold within a time period.
1. A method comprising:
generating a complex baseband signal from a received signal;
determining a phase difference between a phase of the complex baseband signal and a phase precalculated from previous sampled values;
comparing the phase difference with a first threshold;
determining a number by counting exceedances of the first threshold by the phase difference by counting pulses of a clock signal when the phase difference exceeds the first threshold;
comparing the number of the counted exceedances with a second threshold; and
turning off a receiver circuit if the number of counted exceedances exceeds the second threshold within a time period.
2. The method according to claim 1 , wherein the receiver circuit is turned on time-controlled or turned on cyclically.
3. A circuit comprising:
a receiver circuit configured to receive a modulated signal;
a control unit configured to control the receiver circuit, the receiver circuit configured to output a phase difference between a phase of a complex baseband signal and a phase precalculated from previous sampled values; and
an evaluation circuit, which for evaluating the phase difference is connectable to the receiver circuit and the control unit, the evaluation circuit being configured to compare the phase difference with a first threshold and configured to output an output signal based on a number of exceedances of the first threshold by the phase difference, wherein the control unit is configured to turn off the receiver circuit based on the output signal of the evaluation circuit wherein the evaluation circuit has a counter configured to determine the number of exceedances, the counter being configured to count pulses of a clock signal when the phase difference exceeds the first threshold.
4. The circuit according to claim 3 , wherein the receiver circuit has a digital phase-locked loop or a digital demodulator, and wherein the phase-locked loop has a subtractor configured to output the phase difference.
5. The circuit according to claim 3 , wherein the evaluation circuit has a control input for setting the first threshold.
6. The circuit according to claim 3 , wherein the evaluation circuit has a first comparator, which is formed with the receiver circuit or with the output of a subtractor for comparing the phase difference with the first threshold, and wherein the evaluation circuit has a second comparator, which is configured to compare the number determined by the counter with a second threshold and an output of the output signal based on the comparison result of the evaluation circuit.
7. The circuit according to claim 6 , wherein the evaluation circuit has a control input for setting the second threshold.
8. The circuit according to claim 6 , wherein the second threshold is a increasing function of the clock signal.
9. The circuit according to claim 6 , wherein the first comparator is a digital discriminator or a window discriminator.
10. The circuit according to claim 3 , wherein the control unit is configured for a time-controlled and/or event-controlled turning on of the receiver circuit.
11. An apparatus, comprising:
circuitry configured to:
receive a modulated signal;
output a phase difference between a phase of a complex baseband signal and a phase precalculated from previous sampled values;
compare the phase difference with a first threshold;
increment a counter in response to determining that the phase difference exceeds the first threshold, wherein the counter comprises an input connected to a clock signal, the counter configured to count pulses of the clock signal when the phase difference exceeds the first threshold;
compare an output of the counter with a second threshold; and
turn off a receiver circuit in response to determining that the output of the counter exceeds the second threshold.
12. The apparatus of claim 11 , wherein the circuitry comprises a digital phase-locked loop, the digital phase-locked loop configured to determine the phase precalculated from previous sampled values.
13. The apparatus of claim 11 , wherein the circuitry comprises an evaluation circuit comprising:
a first comparator configured to compare the phase difference with the first threshold;
the counter; and
a second comparator configured to compare the output of the counter with the second threshold.
14. The apparatus of claim 13 , wherein the first comparator comprises a control input, the first comparator configured to set the first threshold based on the control input.
15. The apparatus of claim 13 , wherein the second comparator comprises a control input, the second comparator configured to set the second threshold based on the control input.
16. The apparatus of claim 11 , wherein the second threshold is an increasing function of the clock signal.
17. The apparatus of claim 11 , wherein the circuitry comprises a control circuit configured to:
turn off the receiver circuit in response to determining that the output of the counter exceeds the second threshold within the time period; and
turn on the receiver circuit based on a time-control.