Patent ID: 7957496

Claim:
An apparatus for suppressing interference in a received electronic communication signal, comprising; an adaptive filter configured to remove components from said received electronic communications signal, said adaptive filter being operable in a first adaptive mode to adapt to remove all coherent components of said received communications signal, and in a second mode having an at least reduced adaptability compared to said first adaptive mode, wherein said adaptive filter receives said electronic communications signal as a first input, and delayed electronic communications signal as second reference input, wherein said delayed electronic communications signal comprises a noise reference derived from said received electronic communications signal; and a control circuit configured to control the mode of said adaptive filter in dependence on whether said received electronic communication signal contains a signal of interests wherein (A) said control circuit is configured to (i) set said adaptive filter to said second mode when said received electronic communications signal contains said signal of interest; and (ii) set said adaptive filter to said first adaptive mode in the absence of said signal of interest in said received electronic communications signal and (B) said adaptive filter (a) has a filter coefficient set to a last updated value and (b) continues to remove said coherent components without removing said signal of interest; wherein said control circuit comprises a detector located in a downstream of said adaptive filter and is configured to detect the presence of said signal of interest in said received electronic communications signal after filtering by said adaptive filter; wherein said detector has a response time less than an adaptation time of said adaptive filter when said adaptive filter is in said first adaptive mode.