Clear-channel system and related applications
View Patent ↗A wireless spread-spectrum communication system for transmitting data includes a plurality of end point transmitters and at least one receiver. The end point transmitters transmit data via a frequency-hopped spread-spectrum signal where the transmitting signal is sent without the benefit of frequency stabilization. The receiver is responsive to the frequency-hopping spread-spectrum signals and includes a correlator and a signal processor. The correlator samples at least a first portion of a preamble of the signal and correlates the portion of the preamble with a known preamble pattern to determine a probability of correlation. The signal processor applies a Fast Fourier Transform algorithm to the signal in response to the probability of correlation to track a narrowband frequency of the signal based on at least a second portion of the preamble and to decode data encoded within the signal subsequent to the preamble.
1. A frequency-hopping spread-spectrum (FHSS) system for enhancing communications in a given location, the system comprising:
a radio in communication with an endpoint, the endpoint coupled to a utility meter, the radio comprising:
a receiver to receive data in a frequency band;
a microprocessor to analyze the received data to create a band profile of power levels at frequencies across the frequency band; and
a transmitter to transmit the band profile to the endpoint to facilitate communication from the endpoint by the endpoint avoiding noisy channels identified from the band profile,
wherein the receiver receives utility consumption data from the endpoint via FHSS signals transmitted over channels associated with the band profile, and the transmitter transmits the utility consumption data to a utility data collector to be ultimately provided to a central station.
2. The system of claim 1 , wherein the band profile comprises a lookup table.
3. The system of claim 1 , wherein the band profile identifies channels corresponding to times-of-day, the band profile received from the radio to facilitate communication to the radio at a first time-of-day over channels corresponding to the first time-of-day.
4. A data transmission system, comprising:
a frequency-hopping spread-spectrum (FHSS) transmitter configured to transmit signals to a radio on predetermined channels within a predetermined frequency band, the radio to transmit a time-of-day dependent band profile of signal levels;
a utility meter coupled to the FHSS transmitter; and
a receiver configured to receive from the radio the time-of-day dependent band profile of signal levels on the predetermined channels over a predetermined time period, and to identify noisy channels within the predetermined channels based on the band profile,
wherein the FHSS transmitter is configured to transmit utility consumption data provided by the utility meter to the radio on channels other than the identified noisy channels, the utility consumption data to be ultimately retransmitted by the radio to a central station.
5. The system of claim 4 , wherein the band profile identifies relatively clear channels within the predetermined channels to enable the FHSS transmitter to adjust its transmission of signals to transmit signals on the relatively clear channels.
6. The system of claim 4 , further comprising a data-storage device configured to store the band profile as a table accessible to the FHSS transmitter.
7. The system of claim 4 , wherein the band profile is updated based on further signal levels received by the radio on the predetermined channels during further series of measurements.
8. The system of claim 4 , wherein the predetermined frequency band corresponds to one of the industrial, scientific, and medical (ISM) bands.
9. The system of claim 4 , wherein the band profile comprises peak and average power over time for frequencies of the band.
10. The system of claim 4 , wherein the band profile identifies noisy channels corresponding to times-of-day, the band profile received from the radio to facilitate communication to the radio at a first time-of-day on channels other than noisy channels corresponding to the first time-of-day.