Apparatus for and method of digital signal processing

A method of digital signal processing including the steps of:

• feeding a first input signal into a first input channel;
• mixing said first input signal with a vernier frequency, said vernier frequency used as a correction frequency;
• inputting said first input channel into a bank of contiguous digital filters, said digital filters having an overlapping frequency response that together span the bandwidth of said first input signal;
• decomposing said first input signal into subbands;
• summing said sub-bands to produce a reconstructed first input signal.

A method of digital signal processing comprising the steps of:

• feeding a plurality of input signals into a bank of contiguous digital filters, each said input signal input into a predetermined input channel;
• mixing into each said input channel a vernier frequency, said vernier frequency providing correction to said input channel;
• decomposing each said input channel into subbands using an FFT weighted overlap-add demultiplexer;
• decimating said sub-bands by a factor common to a predetermined sampling rate;
• passing said decimated sub-bands each to an appropriate input port of an FFT weighted overlap-add multiplexer, said passing is performed by a switch matrix;
• multiplexing said decimated sub-bands in said FFT multiplexer in order to produce recreated input signals;
• interpolating each said recreated input signal up to a predetermined output sampling rate;
• combining each said recreated input signal with a predetermined carrier frequency;
• and
• frequency division multiplexing said recreated input signals to create an output signal.