Frequency hopping system for intermittent transmission
First Claim
1. A telemetry system comprising:
- a plurality of transmitters, each of which is for transmitting intermittently transmissions, at various transmission frequencies, independently of any other of said plurality of transmitters and independently of any apparatus for receiving any of said transmissions, and a receiver for holding, simultaneously for each of said plurality of transmitters, (a) time data indicative of an expected time of at least one future transmission, and (b) frequency data indicative of an expected transmission frequency of said at least one future transmission.
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Accused Products
Abstract
A radio transmission system including many radio transmitters using frequency hopping carriers to intermittently transmit very short messages indicative of status of stimuli associated with the transmitters. The transmitters transmit transmissions independently of a receiver receiving the transmissions and independent of each other. In operation, radio transmitters transmit messages at varying frequencies at time intervals that can be varied as well. The frequency and time intervals are varied according to patterns that can be determined individually for each transmitter. A receiver holds data indicative of the future transmission frequency and time for each transmitter and updates the data based on the time and the content of the received messages. In addition, a simple method is provided to generate a very large number of orthogonal frequency-time hopping sequences that are individual for each transmitter and based on the transmitter ID.
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Citations
38 Claims
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1. A telemetry system comprising:
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a plurality of transmitters, each of which is for transmitting intermittently transmissions, at various transmission frequencies, independently of any other of said plurality of transmitters and independently of any apparatus for receiving any of said transmissions, and a receiver for holding, simultaneously for each of said plurality of transmitters, (a) time data indicative of an expected time of at least one future transmission, and (b) frequency data indicative of an expected transmission frequency of said at least one future transmission. - View Dependent Claims (2, 3, 4, 5, 6, 7)
said receiver comprises a frequency selective circuit, and wherein in operation, for each of said plurality of transmitters, said receiver changes frequency of said frequency selective circuit to said expected transmission frequency at such time relative to said expected time to receive and demodulate said at least one future transmission. -
4. The system of claim 3 wherein, in operation,
said receiver, during the time between transmissions, changes frequency of said frequency selective circuit to scan at least a portion of a frequency band available for transmissions, in an attempt to receive a transmission from a transmitter with which synchronization has been lost, and when such transmission is received at least in part, said receiver updates, for said transmitter, said time data and said frequency data. -
5. The system of claim 1 or 2 wherein, each of a plurality of said transmissions comprises at least a portion of data indicative of at least one of:
- (a) transmission frequency of a future transmission, and (b) time of a future transmission.
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6. The system of claim 1 or 2 wherein each of a plurality of said transmissions comprises at least a portion of data indicative of at least one of (a) at least a portion of a frequency pattern for varying transmission frequency, and (b) at least a portion of a time pattern for varying time between transmissions.
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7. The system of claim 1 or 2 wherein for each of said plurality of transmitters, upon each of said transmissions, said expected transmission frequency is predictable based on transmission frequency of a past transmission.
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8. A method of operating a telemetry system, said method comprising:
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transmitting, from each or a plurality of transmitters, intermittently transmissions, at various transmission frequencies, independently of any other of said plurality of transmitters and independently of any apparatus for receiving any of said transmissions, and holding, in a receiver, simultaneously for each of said plurality of transmitters, (a) time data indicative of an expected time of a future transmission, and (b) frequency data indicative of an expected transmission frequency of said future transmission. - View Dependent Claims (9, 10, 11, 12, 13, 14, 17, 18)
said receiver, during the time between transmissions, changes frequency of said frequency selective circuit to scan at least a portion of a frequency band available for transmissions in an attempt to receive a transmission from a transmitter with which synchronization has been lost, and when such transmission is received at least in part, said receiver updates, for said transmitter, said data indicative of an expected time and an expected transmission frequency.
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15. A telemetry receiver comprising:
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logic for holding simultaneously for each plurality of transmissions, data indicative of an expected time and an expected transmission frequency of at least one future transmission, wherein each said plurality of transmissions is transmitted by a different one of a plurality of transmitters, and wherein each of said plurality of transmitters is for transmitting intermittently, at various transmission frequencies, independently of any apparatus for receiving any of said transmissions and independently of any other of said plurality of transmitters, and a frequency selective circuit for receiving said transmissions. - View Dependent Claims (16, 19, 20, 21)
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22. A plurality of telemetry transmitters, each of which comprises:
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a circuit for transmitting intermittently transmissions, at various transmission frequencies, independently of any apparatus for receiving any of said transmissions and independently of any other of said plurality of transmitters, and logic for varying transmission frequency, for said transmissions, according to a frequency pattern, and for including in each of a plurality of said transmissions at least a portion of data indicative of at least one of;
(a) transmission frequency of at least one future transmission, and (b) time of at least one future transmission.- View Dependent Claims (23, 24, 25, 26)
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27. A plurality of telemetry transmitters, each of which comprises:
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a circuit for transmitting intermittently transmissions, at various transmission frequencies, independently of any apparatus for receiving any of said transmissions and independently of any other of said plurality of transmitters, and logic for controlling transmission frequency and time between transmissions, for said transmissions, according to a frequency-time pattern, and for including in each of a plurality of said transmissions at least a portion of data indicative of at least a portion of said frequency-time pattern. - View Dependent Claims (28, 29, 30, 31)
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32. A plurality of telemetry transmitters, each of which comprises:
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a synthesizer circuit for producing transmission frequency based on a reference frequency, wherein said synthesizer circuit can be programmed to produce said transmission frequency at any of a multiplicity of preestablished frequency channels, and an oscillator for producing said reference frequency, and wherein, in operation, each of said plurality of transmitters transmits intermittently transmissions independently of any apparatus for receiving any of said transmissions and independently of any other of said plurality of transmitters, wherein frequency channels for said transmissions are selected in a sequence according to a frequency pattern. - View Dependent Claims (33, 34, 35, 36, 37, 38)
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Specification