Design of FIR sampled-data filters for data transmission

A technique is presented for the design of finite-duration-impulse-response (FIR) sampled-data filters which can be used for data transmission as Nyquist channel filters. The filters have zero intersymbol interference in the time domain, as well as linear phase and arbitrary attenuation characteristics in the frequency domain. Compared with more elaborate optimization techniques, the proposed method gives an optimum solution, and it has a number of advantages and features. In the critical case of two samples per baud interval, the resulting filter amplitude response has a remarkable property: if the frequencies of perfect transmission in the passband are specified (or obtained), than, in the Ω-domain, the method results automatically in an equal number of zeros of transmission in the stop band, whose values are the inverses of those at which perfect transmission occurs. This property is akin to that of elliptic filters and is inherent in this special case of the design method