Calibration of differential frequency-dependent characteristics of a radio communications system
First Claim
1. A signal processor to determine a group delay calibration vector based on at least two frequency bands of a received transponder signal, the signal processor comprising:
- a circuit to compare relative characteristics for the transponder signal at a first one of the at least two frequencies to relative characteristics for the transponder signal at a second one of the at least two frequencies; and
a circuit to determine a group delay calibration vector from the comparison.
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Accused Products
Abstract
A method and apparatus are provided that determine a frequency dependent calibration vector for a set of transmit or receive chains of a radio communications system using only differential phase and amplitude between the transmit chains and the receive chains, respectively. In one embodiment, the invention includes an antenna array adapted to transmit and receive radio communications signals with a plurality of other terminals, a transmit chain to transmit a calibration signal through the antenna array to a transponder on at least two different frequency bands, and a receive chain to receive through the antenna array a transponder signal from the transponder, the transponder signal being received on at least two different frequency bands and being based on the calibration signal. A signal processor determines a frequency dependent calibration vector based on the at least two frequency bands of the transponder signal as received through the receive chain by comparing relative characteristics for the transponder signal at a first one of the at least two frequencies to relative characteristics for the transponder signal at a second one of the at least two frequencies.
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Citations
27 Claims
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1. A signal processor to determine a group delay calibration vector based on at least two frequency bands of a received transponder signal, the signal processor comprising:
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a circuit to compare relative characteristics for the transponder signal at a first one of the at least two frequencies to relative characteristics for the transponder signal at a second one of the at least two frequencies; and
a circuit to determine a group delay calibration vector from the comparison. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method comprising:
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receiving at least two frequency bands of a transponder signal;
comparing relative characteristics for the transponder signal at a first one of the at least two frequencies to relative characteristics for the transponder signal at a second one of the at least two frequencies; and
determining a delay compensation vector from the comparison. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. A machine-readable medium having stored thereon instructions which, when executed by a machine, cause the machine to perform operations comprising:
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receiving at least two frequency bands of a transponder signal;
comparing relative characteristics for the transponder signal at a first one of the at least two frequencies to relative characteristics for the transponder signal at a second one of the at least two frequencies; and
determining a delay compensation vector from the comparison. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27)
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Specification