Patent ID: 7623604

Claim:
An apparatus for suppressing interference in a received communications signal, comprising: an adaptive filter configured to remove components from said received communications signal, said adaptive filter being operable in a first adaptive mode to adapt to changes in said received communications signal, and in a second mode having an at least reduced adaptability compared to said first mode, wherein said adaptive filter receives said communications signal as a first input, and a delayed communications signal as a second reference input, wherein said delayed communications signal comprises a noise reference derived from said communications signal; and a control circuit configured to control the mode of said adaptive filter in dependence on whether said received communications signal contains a signal of interest, wherein (A) said control circuit comprises a detector configured to detect the presence of said signal of interest in said received communications signal, (B) said detector comprises (i) a first detection section configured to detect the presence of a coherent component in said received communications signal, and (ii) a classification section configured to classify whether said detected coherent component is said signal of interest and (C) said control circuit is configured, responsive to detection of said coherent component by said first detection section, to (i) generate a control signal to set said adaptive filter to said second mode, (ii) generate a control signal to keep said adaptive filter in said second mode if said coherent component is classified as being said signal of interest and (iii) generate a control signal to set said adaptive filter to said first adaptive mode if said coherent component is classified as not being said signal of interest.