Techniques for implementing adaptation control of an echo canceller to facilitate detection of in-band signals

A communication device, comprising:

• a control circuit;
• an adaptive filter in communication with the control circuit, wherein the adaptive filter is configured to perform a first adaptation in response to detection of a far-end harmonic signal, and wherein the adaptive filter provides an echo estimation signal and the adaptive filter is further configured to perform a second adaptation in response to detection of a far-end non-harmonic signal;
• an adder in communication with the control circuit, wherein the adder is configured to subtract the echo estimation signal from a near-end signal that includes one or more in-band signaling tones to provide an error signal;
• and
• a tone detector in communication with the control circuit, wherein the tone detector is configured to detect the one or more in-band signaling tones in the error signal, and wherein the first adaptation modifies filter coefficients of the adaptive filter and the filter coefficients are finite impulse response (FIR) time-domain filter coefficients.

An echo canceller, comprising:

• a processor circuit configured to:
• implement an adaptive filter that is configured to perform a first adaptation in response to detection of a far-end harmonic signal, wherein the adaptive filter provides an echo estimation signal;
• subtract the echo estimation signal from a near-end signal that includes one or more in-band signaling tones to provide an error signal;
• provide the error signal to a tone detector that is configured to detect the one or more in-band signaling tones in the error signal;
• and
• perform a second adaptation in response to detection of a far-end non-harmonic signal.