A new way of generating the nyquist spectral‐shaped high‐speed and multilevel digital signals

High‐speed waveform transmission is of great importance in the realization of digital radio systems with high spectrum utilization efficiency. the binary transversal filter (BTF) offers an effective technique for achieving high‐precision waveform generation because it is a means of producing the desired waveform directly in the time domain. This paper presents a new technique for design of the BTF and discusses the authors' experimental results. the new BTF can be applied quite easily to high‐speed multilevel signals and is composed of a shift register, a programmable ROM (PROM) and a D/A converter which are driven by a multiphase clock. A was used to design the basic parameters of the BTF: sampling frequency, number of taps and tap coefficients, quantization levels for the D/A converter and allowable phase error for the clock signal. an analysis was conducted to determine the effect that each factor has the spectral characteristics and intersymbol interference characteristics. Further it was shown that based on this configuration and design method, a 12.5‐MB 4‐level Nyquist waveform can be realized without adjustment.