Method and system for receiving pulse width keyed signals
View Patent ↗Provided is a method to process a pulse width coded signal. the method includes digitizing a received pulse width coded signal and transforming the digitized signal to at least one of power domain and absolute value domain. The converting produces a converted signal. The method also includes estimating a signal power of the converted signal in a wide band filter to produce data representative of a first signal having first type signal shape properties and estimating a signal power of the converted signal in a narrow band filter to produce data representative of a second signal having second type signal shape properties. Finally, the first and second type data are compared to produce information representative of pulse width characteristics of the received signal.
1. A method to process a pulse width coded signal, comprising:
digitizing a received pulse width coded signal;
transforming the digitized signal to at least one of power domain and absolute value domain, the transforming producing a converted signal;
estimating a signal power of the converted signal in a wide band filter to produce data representative of a first signal having first type signal shape properties;
estimating a signal power of the converted signal in a narrow band filter to produce data representative of a second signal having second type signal shape properties; and
comparing the first and second signal data to produce information representative of pulse width characteristics of the received signal.
2. The method of claim 1 , further comprising down sampling each of the first and second type data prior to the comparing.
3. The method of claim 2 , wherein the down sampling includes down sampling from within a range of between eight and a value less than a sampling increment associated with each of the estimating steps.
4. The method of claim 1 , wherein each of the estimating steps includes performing moving average filtering.
5. The method of claim 4 , wherein the moving average filtering includes averaging converted signal data in increments of eight.
6. The method of claim 5 , wherein the wideband estimating includes filtering the converted signal in time periods within a range of about 8 to 256 microseconds; and
wherein the narrowband estimating includes filtering the converted signal at in time periods within a range of about 256 to 512 microseconds.
7. An apparatus, comprising:
an analog to digital converter (ADC) configured to receive an analog input signal;
a power converter configured to receive a signal output from the ADC;
an absolute value converter configured to receive a signal output from the ADC;
a multiplexer configured to select an output from one of the power converter and the absolute value converter;
a first filter configured perform a first time period integration on a signal output form the multiplexing device; and
a second filter configured to perform a second time period integration on the signal output from the multiplexing device.
8. The apparatus of claim 7 , further comprising respective down sampling devices configured to receive output from the first and second filter.
9. The apparatus of claim 8 , wherein the respective down sampling devices are configured to produce first and second type waveform data.
10. The apparatus of claim 9 , further comprising a combiner configured to combine outputs of the respective down sampling devices.
11. The apparatus of claim 10 , wherein the combiner is configured to produce third type waveform data.
12. The apparatus of claim 11 , further comprising a threshold circuit to determine thresholds associated with the first, second, and third type waveform data.
13. The apparatus of claim 12 , wherein the threshold circuit produces first and second time of arrival data (TOA);
wherein the first TOA data is used to determine a TOA associated with the input analog signal; and
wherein the second TOA data is used to confirm the determined TOA.
14. An apparatus to process to process a pulse width coded signal, comprising:
means for digitizing a received pulse width coded signal;
means for transforming the digitized signal to at least one of power domain and absolute value domain, the transforming producing a converted signal;
means for estimating a signal power of the converted signal in a wide band filter to produce data representative of a first signal having first type signal shape properties;
means for estimating a signal power of the converted signal in a narrow band filter to produce data representative of a second signal having second type signal shape properties; and
means for comparing the first and second type data to produce information representative of pulse width characteristics of the received signal.
15. The apparatus of claim 14 , further comprising means for down sampling each of the first and second type data prior to the comparing.
16. The method of claim 15 , wherein the means for down sampling includes down sampling from within a range of between eight and a value less than a sampling increment associated with each of the estimating steps.
17. The method of claim 16 , wherein each of the means for estimating includes means for performing moving average filtering.