VOCAL Technologies, Ltd. now offers an effective and efficient Adaptive Interference Cancellation (AIC) software.  AIC  is an system identification adaptive filtering problem.  It can be applied to any solution in which there are two input sources.  As shown in Figure 1, one input source, s1(n), contains a desired signal and a linear transformed copy of an interfering signal.  The second input source, s2(n), contains a  reference of the interfering signal.  An adaptive equalizer can be applied to the s2(n) and subtracted from s1(n) to remove interfering source from s1(n).


The most common and well known application of adaptive interference cancellation is acoustic echo cancellation (AEC).  In the AEC scenario, s2(n) is the loudspeaker signal and s1(n) is the microphone signal which contains echoes of the s2(n) signal and a desired sound source.

Other popular applications of AIC include active noise cancellation and adaptive beamforming algorithms such as the Generalized Sidelobe Canceller.  Each of these applications have their own design considerations and have different constraints on achievable performance.  For example, in echo cancellation s2(n) is a direct reference of the interfering source signal, but in active noise cancellation, s2(n) is not a direct reference of the interfering signal, thus it will be less correlated with signal in s1(n), and less attenuation will be achieved.  In adaptive beamforming, some of the desired signal may leak into s2(n) and if not controlled properly could result in the removal of the desired signal from s1(n).

However, AIC serves as the basic building block for software for all of these applications.  VOCAL AIC solutions offers both time domain and subband domain implementations.  Time domain implementation is best for applications in open air environments, while the subband implementation are best enclosed spaces such as offices and conference rooms.  At VOCAL we have the expertise to provide you the AIC solution that best meets your requirements and design constraints.