Issues in the design of digital Nyquist filters

The authors examine the tradeoffs involved in the design of digital raised-cosine Nyquist filters for application in digital computer simulation or for incorporation in all-digital data modems. Both floating-point arithmetics (for simulation applications) and finite-precision arithmetics are considered. Tapped-delay-line (finite impulse response) with time- or frequency-domain design, direct-form infinite-impulse-response, Rao-Kailath, and Lei-Yao structures are examined. The main criteria for a comparison among the various solutions, besides their relative complexities, are the digital filter behavior in the time domain (residual intersymbol interference) and in the frequency domain (stopband attenuation)