Multi-channel echo canceling method and apparatus
First Claim
1. A multi-channel echo canceling method of subtracting, from a mixed signal or signals in which echoes produced from a plurality of reception signals are mixed with a transmission signal or signals, a replica of the echoes in order to cancel the echoes of the mixed signal or signals, the method comprising at least the steps of:
- selecting the reception signal that is most leading in phase; and
producing a replica of the echoes from the selected reception signal.
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Abstract
Echo canceling method and apparatus for subtracting, from a mixed signal in which echoes produced from a plurality of reception signals are mixed with a transmission signal, a replica of the echoes in order to cancel the echoes in the mixed signal. The replica of the echoes are generated by the steps of selecting the reception signal which is leading in phase and producing a replica of the echoes from the selected reception signal by an adaptive filter. Generally, the replicas are produced by adaptive filters provided in one-to-one correspondence with the mixed signals.
71 Citations
22 Claims
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1. A multi-channel echo canceling method of subtracting, from a mixed signal or signals in which echoes produced from a plurality of reception signals are mixed with a transmission signal or signals, a replica of the echoes in order to cancel the echoes of the mixed signal or signals, the method comprising at least the steps of:
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selecting the reception signal that is most leading in phase; and producing a replica of the echoes from the selected reception signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A multi-channel echo canceling apparatus for subtracting, from a mixed signal in which an echo produced from a plurality of reception signals are mixed with a transmission signal or signals, a replica of the echo in order to cancel the echo of the mixed signal or signals, comprising:
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a phase difference detecting circuit for receiving the reception signals and detecting the reception signal which is most leading in phase; a selector for receiving the reception signals and selectively outputting, in accordance with the results of the detection by said phase difference detecting circuit, the reception signal which is most leading in phase; an adaptive filter provided in one-to-one correspondence with the mixed signal for receiving the output of the selector and producing and outputting a replica of the echo; and a subtracter provided in one-to-one correspondence with the mixed signal for subtracting the output of the adaptive filter from the mixed signal; the adaptive filter being controlled so as to minimize the output of the subtracter. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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Specification