Adaptive filter based on a recursive delay line

An adaptive recursive filter for filtering electronic signals is disclosed. The filter comprises a plurality of cells connected sequentially. Each cell comprises a delay element; a means to multiply the output of the delay element by a first adaptive parameter, thus creating an adaptive feedback signal; a means to multiply the input to the cell by a second adaptive parameter, thus creating an adaptive input signal; and a first summation means to add the adaptive feedback signal to the adaptive input signal. The output gain of each cell is further multiplied by an adaptive weighing factor and all of the thus-created adaptively modified cell output gains are added together linearly by a plurality of second summation elements thus producing the output of the filter. This filter is characterized by a fully adaptive set of coefficients, an impulse response length decoupled from its order, and easily enforced stability conditions.