Patent ID: 8539012

Claim:
An improved multi-rate digital filter comprising: a first path including a full-rate Finite Impulse Response (FIR) filter FIR F , the full-rate filter FIR F receiving and filtering an input signal to produce a filtered full-rate signal; a second path in parallel to the first path and also receiving the input signal, the second path sequentially comprising: a down sampler processing the input signal to produce a reduced-rate signal; a reduced-rate FIR filter FIR R in signal communication with the down sampler to receive and processing the reduced-rate signal to produce a filtered reduced-rate signal; and an up sampler in signal communication with the reduced-rate filter FIR R to receive and process the filtered reduced-rate signal and to provide an up sampled filtered signal; and a summer in signal communication with the full-rate filter FIR F to receive the filtered full-rate signal and in signal communication with the reduced-rate filter FIR R to receive the up sampled filtered signal, the summer summing the filtered full-rate signal and the up sampled filtered signal to provide a filtered signal.