METHOD AND APPARATUS FOR CROSS-TALK CANCELLATION
First Claim
1. A method of cross-talk cancellation in a transceiver having a transmitter which signal processes and transmits a transmit signal, and a receiver which receives and signal processes a receive signal, the receive signal including therein a transmit cross-talk signal being at least a partial representation of the transmit signal, the method comprising:
- obtaining the transmit signal to be signal processed and transmit by the transmitter;
signal processing the transmit signal to produce a cross-talk cancellation signal, the signal processing comprising applying to the transmit signal one or more signal processing operations which emulate the generation of the transmit cross-talk signal from the transmit signal in the receiver; and
combining the cross-talk cancellation signal with the receive signal containing the transmit cross-talk signal to thereby substantially remove or reduce the transmit cross-talk signal from the receive signal.
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Accused Products
Abstract
The present invention addresses the problem of a second (or higher) order representation of a transmit signal which is transmitted by a transceiver being mixed into the region of the frequency spectrum of interest to the transceiver receiver, such that it can not then be spectrally filtered out. At its most straightforward, in one embodiment of the invention this is achieved by providing a cross-talk cancellation unit which takes the transmit signal, and obtains the second (or higher) order representation thereof. This representation is then subtracted from the received signal before the signal is passed to the radio control receiver signal processing elements. However, in a more preferred arrangement a filter is also provided, to filter the second or higher order version of the transmit signal, prior to its being subtracted from the received signal. The filter basically takes out the effects of any other filtering or processing which has happened to the transmit signal in the receiver signal chain. This would be, for example, the filtering effects provided by the anti-aliasing filter in the receiver.
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Citations
26 Claims
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1. A method of cross-talk cancellation in a transceiver having a transmitter which signal processes and transmits a transmit signal, and a receiver which receives and signal processes a receive signal, the receive signal including therein a transmit cross-talk signal being at least a partial representation of the transmit signal, the method comprising:
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obtaining the transmit signal to be signal processed and transmit by the transmitter; signal processing the transmit signal to produce a cross-talk cancellation signal, the signal processing comprising applying to the transmit signal one or more signal processing operations which emulate the generation of the transmit cross-talk signal from the transmit signal in the receiver; and combining the cross-talk cancellation signal with the receive signal containing the transmit cross-talk signal to thereby substantially remove or reduce the transmit cross-talk signal from the receive signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A transceiver comprising:
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a transmitter which signal processes and transmits a transmit signal; and a receiver which receives and signal processes a receive signal, the receive signal including therein a transmit cross-talk signal being at least a partial representation of the transmit signal;
the transceiver further comprising;a cross-talk canceller for substantially removing or reducing the transmit cross-talk signal from the receive signal, the cross-talk canceller comprising;
an input for receiving the transmit signal to be signal processed and transmit by the transmitter;
at least one signal processing element which signal processes the transmit signal received at the input to produce a cross-talk cancellation signal, the signal processing element being arranged to perform one or more signal processing operations which emulate the generation of the transmit cross-talk signal from the transmit signal, in the receiver; anda signal combiner arranged to combine the cross-talk cancellation signal with the receive signal containing the transmit cross-talk signal to thereby substantially remove or reduce the transmit cross-talk signal from the receive signal. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A cross-talk canceller for cancelling a cross-talk signal in a receiver due to a transmitted signal transmit from a transmitter, the cross-talk canceller comprising an input which receives a copy of the baseband signal to be transmit, at least one amplifier which amplifies the copy of the baseband transmission signal in dependence on amplifier gain factors applied to the transmit signal in the transmitter and/or a received signal in the receiver, a multiplier to increase the order of the baseband transmit signal to at least the second order, an estimator which estimates the cross-talk signal path and filters the higher order transmit signal in accordance with the cross-talk path estimate to generate an estimated version of the cross-talk signal, and a subtractor which subtracts the estimated version of the cross-talk from the signal being processed by the receiver to thereby cancel the cross-talk signal therefrom.
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24. A method of cancelling a cross-talk signal in a receiver due to a transmitted signal transmit from a transmitter, comprising receiving a copy of a baseband signal to be transmit;
- amplifying the copy of the baseband transmission signal in dependence on amplifier gain factors applied to the transmit signal in the transmitter and/or a received signal in the receiver;
increasing the order of the baseband transmit signal to at least the second order;
estimating the cross-talk signal path and filtering the higher order transmit signal in accordance with the cross-talk path estimate to generate an estimated version of the cross-talk signal, and subtracting the estimated version of the cross-talk from the received signal being processed by the receiver to thereby cancel the cross-talk signal therefrom.
- amplifying the copy of the baseband transmission signal in dependence on amplifier gain factors applied to the transmit signal in the transmitter and/or a received signal in the receiver;
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25. A transceiver substantially as hereinbefore described with reference to the accompanying drawings.
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26. A method of cancelling cross-talk in a transceiver substantially as hereinbefore described.
Specification