Noise Loading Analysis in FDM Systems

This paper investigates the characterization of nonlinear distortion produced in FDM systems under high-frequency operation, by using noise loading techniques. By employing a general Volterra-based model, the paper develops an appropriate noise loading technique for the assessment of nonlinear distortion in such wide-band transmission systems. The advantage of using Volterra series representation is that it takes account of system nonlinear-memory behavior in a combined formulation.     

On Moments and Walsh Characteristic Functions

This correspondence treats the derivation of natural moments from their corresponding Walsh characteristic function via the dyadic derivative operator. The derivation of a result concerning Walsh transforms of dyadic derivatives of functions is also considered. However, some established ideas such as Walsh transform, dyadic stationarity, and dyadic correlation are introduced first.     

On the Walsh Analysis of Nonlinear Systems

This paper considers some aspects of the analysis of nonlinear systems via Walsh functions. Two basic approaches are investigated. These are 1) a characteristic-function method which assumes a Walsh-transformable nonlinearity and 2) a matrix method that is suitable when the input can be represented by a truncated Walsh series expansion. Illustrative examples are included.     

Walsh Series Expansions of Probability Distributions

This paper discusses the representation of probability distribution functions by Walsh series expansions. Generally, such expansions may be employed for the representation of multivariate distributions. However, we confine attention here to univariate and bivariate distributions. The resulting expansions are consequently utilized in the derivation of useful expressions for the moments of corresponding probability distributions. Applications of Walsh expansions of probability distributions are further illustrated by computing output moments for some general classes of nonlinear systems.     

Performance of Baseband Digital Data Transmission in Nonlinear Channels with Memory

This paper considers the performance of digital data transmission in nonlinear channels with memory. The analysis is based on the application of a particular form of Volterra series representation for the nonlinear system describing the transmission channel. First, expressions are derived for the output mean and power spectral density under certain conditions. Next, the paper presents a computationally convenient expression for the error rate involved in such transmission.