Patent ID: 6993464

Claim:
A method for finding an optimized filter parameters design for a digital IF programmable downconverter, comprises the following steps: (1) receiving an input specification, said input specification comprising an input signal sampling rate, an input data rate, an oversampling factor R, an available number of Halfband decimation filters, a passband frequency, a stopband frequency, a passband ripple, a stopband attenuation and a optimal filter parameter satisfying said input specification; (2) determining if said oversampling factor R is equal to 1; (3) obtaining an largest available number nHB of Halfband decimation filters and setting an initial value of nHB equal to a total of Halfband decimation filters; (4) obtaining an largest available first number of Halfband decimation filters satisfying said input specification and determining if re-sampling FIR filter is necessary; (5) obtaining an optimized combination of Halfband decimation filters satisfying said input specification; (6) obtaining a total n of window function for designing filters; (7) obtaining a window function index j and setting said windows function index to 1; and (8) obtaining a programmable FIR filter satisfying said input specification.