Appeal No. 2006-1690
Application No. 10/154,185
are configurable by first and second weights respectively. Control logic coupled
to both filters compares error signals from both filters and replaces the non-
adaptive filter's weights with the adaptive filter's weights if the non-adaptive filter's
error signal has a higher signal power than that of the adaptive filter. If double-
talk is detected, however, the control logic suspends replacement of the non-
adaptive filter's weights before portions of the first signal are cancelled by the
non-adaptive filter.
Representative claim 1 is reproduced as follows:
An apparatus comprising:
a non-adaptive filter configurable by a first set of weights to perform echo
cancellation on a first signal;
an adaptive filter configurable by a second set of weights to perform echo
cancellation on the first signal; and
a control logic coupled to the adaptive and non-adaptive filters, the control
logic to receive a first error signal corresponding to the non-adaptive filter, and a
second error signal corresponding to the adaptive filter, and replace the first set
of weights in the non-adaptive filter with the second set of weights if the first error
signal has a higher signal power than the second error signal,
wherein if double-talk is detected the control logic suspends replacement
of the non-adaptive filter weights before portions of the first signal are cancelled
by the non-adaptive filter.
The examiner relies on the following references:
Park et al. (Park) 6,181,794 Jan. 30, 2001
El Malki 5,920,548 Jul. 6, 1999
Sankaran et al. (Sankaran), "Convergence Analysis Results for the Class of
Affine Projection Algorithms," Proc. of IEEE Int'l Symp. on Circuits & Systems,
Orlando, FL, Vol. III, pp. 251-254, May 1999.
2
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