Design of high-speed digital filters suitable for multi-DSP implementation

A multipath signal processing scheme is proposed to overcome the limitation on throughput rate of present-day LSI devices using a number of digital signal processors. Two methods are proposed to realize a given transfer function H(z) for a digital filter with a throughput rate speed that is N times higher than in conventional methods. The first method, the delayed multipath approach, uses an N-path structure as a building element. These N elements are connected successively with increasing delay units to realize a given transfer function. The second method preprocesses the input signal sequence with an FFT processor and follows it up by N of constituent transfer functions derived from H(z) having real coefficients. The output of these N constituent transfer functions is finally post processed by an inverse FFT processor to obtain the desired output signal. The number of the constituent transfer functions is double for a special case when the transfer function to be implemented has complex valued coefficients.