Tag frequency control
First Claim
1. A communication system comprising:
- one or more transceiver units of a first type;
a data store accessible to each transceiver unit of the first type;
two or more transceiver units of a second type, the transceiver units of a second type being capable of communicating with the transceiver units of the first type, and each transceiver unit of the second type comprising a local frequency reference unit on which the frequency of signals transmitted by it are dependent;
wherein;
at least one transceiver unit of the first type comprises;
a frequency comparison unit configured to make a comparison of the frequency of a signal received from a transceiver unit of the second type with a reference frequency and to form an offset signal representative of the offset between the frequency of the signal received from the transceiver unit of the second type with the reference frequency, anda feedback unit configured to update the data store with feedback data representative of the offset signal in respect of that transceiver unit of the second type; and
each transceiver unit of the first type comprises a frequency adjustment unit configured to adjust a transmit and/or receive frequency of the at least one transceiver unit of the first type for communication with one of the transceiver units of the second type in accordance with feedback data stored in the data store in respect of that transceiver unit of the second type.
1 Assignment
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Accused Products
Abstract
A communication system comprising one or more transceiver units of a first type and one or more transceiver units of a second type capable of communicating with the transceiver units of the first type; each transceiver unit of the first type comprising: a frequency comparison unit for comparing the frequency of a signal received from a transceiver unit of the second type with a reference frequency; a feedback signal generator for generating a feedback signal dependent on the result of that comparison; and a transmitter for transmitting that signal to the transceiver unit of the second type; and each transceiver unit of the second type comprising: a local frequency reference unit on which the frequency of signals transmitted by it are dependent; and a frequency adjustment unit for receiving the feedback signal and adjusting the local frequency reference unit in dependence on the feedback signal.
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Citations
23 Claims
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1. A communication system comprising:
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one or more transceiver units of a first type; a data store accessible to each transceiver unit of the first type; two or more transceiver units of a second type, the transceiver units of a second type being capable of communicating with the transceiver units of the first type, and each transceiver unit of the second type comprising a local frequency reference unit on which the frequency of signals transmitted by it are dependent; wherein; at least one transceiver unit of the first type comprises; a frequency comparison unit configured to make a comparison of the frequency of a signal received from a transceiver unit of the second type with a reference frequency and to form an offset signal representative of the offset between the frequency of the signal received from the transceiver unit of the second type with the reference frequency, and a feedback unit configured to update the data store with feedback data representative of the offset signal in respect of that transceiver unit of the second type; and each transceiver unit of the first type comprises a frequency adjustment unit configured to adjust a transmit and/or receive frequency of the at least one transceiver unit of the first type for communication with one of the transceiver units of the second type in accordance with feedback data stored in the data store in respect of that transceiver unit of the second type. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A communication system comprising:
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one or more transceiver units of a first type; two or more transceiver units of a second type, the transceiver units of a second type being capable of communicating with the transceiver units of the first type, and each transceiver unit of the second type comprising a local frequency reference unit on which the frequency of signals transmitted by it are dependent; wherein at least one transceiver unit of the first type comprises; a frequency comparison unit configured to compare the frequency of signals received from transceiver units of the second type with a reference frequency and to form an offset signal representative of the average offset between the frequency of the received signals and the reference frequency; and a frequency adjustment unit for adjusting the reference frequency in accordance with the offset signal. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A method for adjusting the transmit and/or receive frequency of a transceiver unit in a communication system comprising one or more transceiver units of a first type, and two or more transceiver units of a second type, the transceiver units of a second type being capable of communicating with the transceiver units of the first type;
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the method comprising; making a comparison of the frequency of a signal received by a transceiver unit of the first type from a transceiver unit of the second type with a reference frequency; forming an offset signal representative of the offset between the frequency of the signal received from the transceiver unit of the second type with the reference frequency; storing feedback data representative of the offset signal in respect of that transceiver unit of the second type; and adjusting the transmit and/or receive frequency of the transceiver unit of the first type for communication with one of the transceiver units of the second type in accordance with feedback data stored in respect of that transceiver unit of the second type.
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23. A method for adjusting a reference frequency of a transceiver unit in a communication system comprising one or more transceiver units of a first type, and two or more transceiver units of a second type, the transceiver units of the second type being capable of communicating with the transceiver units of the first type, each transceiver unit of the second type comprising a local frequency reference unit on which the frequency of signals transmitted by it are dependent;
- the method comprising;
comparing the frequency of signals received from transceiver units of the second type with a reference frequency; forming an offset signal representative of the average offset between the frequency of the received signals and the reference frequency; and adjusting the reference frequency in accordance with the offset signal.
- the method comprising;
Specification