Dual mode AM-FM receiver with I-Q decoding, such as for utility data collection
First Claim
Patent Images
1. In a utility meter reading system having multiple utility meters wirelessly transmitting utility meter data to a data collection unit, a data collection system comprising:
- a utility data encoder-transmitter connected to each of the utility meters, wherein the encoder-transmitter is configured to wirelessly transmit AM or FM utility metering data, wherein the transmitted AM or FM utility metering data includes differing AM or FM preambles, respectively; and
a data collection unit comprising a dual-mode receiver configured to demodulate and decode the wirelessly transmitted AM, FM, or AM and FM utility metering data signal, wherein the mobile data collection unit is configured to;
receive the transmitted AM or FM signal;
sample and quantize the received signal;
compute a frequency spectrum from the received signal;
demodulate the received signal by both an AM demodulator and an FM demodulator that both use the computed frequency spectrum;
check both demodulated signals for either the AM preamble or the FM preamble;
select and route the demodulated signal having either the AM preamble or the FM preamble to be decoded in a decoder; and
decode the routed demodulated signal.
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Abstract
Methods and apparatus demodulate and decode a plurality of AM and FM arriving signals, which permit, for example, a utility data-collecting unit to concurrently receive and decode transmitted signals of legacy transmitters as well as more recent FM based transmitters, or signals arriving from hybrid systems configured to transmit both AM and FM.
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Citations
30 Claims
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1. In a utility meter reading system having multiple utility meters wirelessly transmitting utility meter data to a data collection unit, a data collection system comprising:
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a utility data encoder-transmitter connected to each of the utility meters, wherein the encoder-transmitter is configured to wirelessly transmit AM or FM utility metering data, wherein the transmitted AM or FM utility metering data includes differing AM or FM preambles, respectively; and
a data collection unit comprising a dual-mode receiver configured to demodulate and decode the wirelessly transmitted AM, FM, or AM and FM utility metering data signal, wherein the mobile data collection unit is configured to;
receive the transmitted AM or FM signal;
sample and quantize the received signal;
compute a frequency spectrum from the received signal;
demodulate the received signal by both an AM demodulator and an FM demodulator that both use the computed frequency spectrum;
check both demodulated signals for either the AM preamble or the FM preamble;
select and route the demodulated signal having either the AM preamble or the FM preamble to be decoded in a decoder; and
decode the routed demodulated signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. In a wireless data communication system, an apparatus comprising:
a dual-mode receiver configured to;
receive data signals from at least one transmitter unit;
sample the received data signal;
transform the sampled signal into frequency components;
demodulate the sampled signal by an AM and FM demodulator utilizing the frequency components;
analyze preambles of the demodulator output to identify information-bearing AM and FM signals;
select and route demodulated signals according to the analyzed preambles; and
decode the selected and routed demodulated signal. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. A dual-mode AM-FM decoding method comprising:
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receiving at least one data signal from at least one of multiple transmitter units, wherein the received data signal is either an AM signal or an FM signal;
sampling the received data signal;
transforming the sampled signal into its frequency components;
AM and FM demodulating the signal utilizing the signal frequency components;
identifying information-bearing demodulated signals;
selecting and routing the information-bearing signals to a decoder; and
decoding the selected signals. - View Dependent Claims (18, 19)
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20. A wireless data acquiring system, comprising:
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a means for receiving at least one data signal from at least one of multiple transmitter units, wherein the received data signal is either an AM or an FM signal;
a means for sampling the received signal;
a means for transforming the sampled signal into frequency components;
a means for AM and FM demodulating the signal utilizing the frequency components;
a means for identifying information-bearing demodulated signals;
a means for selecting and routing information-bearing signals to a decoder; and
a means for decoding the selected signals.
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21. An apparatus for use with a data acquiring system, the apparatus comprising:
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a fast Fourier transformer to convert a received signal into frequency components, wherein the received signal is either an AM or an FM signal having distinguishing portions;
an AM demodulator, coupled with the fast Fourier transformer, to demodulate the received signal utilizing the signal frequency components;
an FM demodulator, coupled with the fast Fourier transformer, to demodulate the received signal utilizing the signal frequency components;
at least one correlator, coupled with the AM demodulator and with the FM demodulator, to identify whether the received signal is an information-bearing signal based on the distinguishing portion of the received signal; and
a selector to select and route an output from the AM demodulator or the FM demodulator based on the identified distinguishing portion of the received signal. - View Dependent Claims (22, 23, 24)
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25. A dual-mode wireless data acquisition apparatus comprising:
a signal processing system configured to receive frequency components of a first signal, a second signal, or a combination of the first and the second signal, and further configured to;
demodulate, in parallel, the first and the second signals, utilizing the frequency domain components of the first and the second signals;
validate one of two preambles of the first and the second demodulated signals; and
identify for further processing the first or second demodulated signal based on which of the two preambles is valid. - View Dependent Claims (26, 27, 28)
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29. An method for frequency shift keying (“
- FSK”
) demodulation of binary data, the method comprising;
calculating a cross-product of a carrier signal phasor computed from a most recent I-Q channel sample with a carrier signal phasor computed from an I-Q channel sample immediately preceding the most recent sample; and
determining a change in the calculated cross-product, wherein the change in the calculated cross-product indicates a change in modulating logic level, from a binary ‘
1’
to a ‘
0’
or from a ‘
0’
to a ‘
1’
. - View Dependent Claims (30)
- FSK”
Specification