Construction and characteristics of codewords and pulse shapes that satisfy spectral constraints

Constrained sequence codes and pulse shapes are used to control signal characteristics in digital communication systems. This letter outlines a technique to construct codewords and pulse shapes to meet specified spectral constraints. Based on a block-coded representation of the signal, it is shown how symbol values can be evaluated to satisfy the most significant terms of a Fourier series representation of the desired spectral response. Several properties of the resulting signals are given, and examples are presented to confirm the validity of this approach.