Note 62. Generating Analytic Signals with Frequency-Shifted FIR Lowpass Filters
A useful technique for designing FIR analytic signal generation (ASG) filters is presented by Reilly et al. in . The basic idea is to design a “standard” lowpass filter having real-valued coefficients, and then phase-shift the impulse response coefficients such that the filter’s passband is shifted to cover only positive frequencies and the stopband is shifted to cover only negative frequencies. The phase-shifted coefficients are complex-valued. The details are provided in Design Procedure 62.1.