Reference phase of pseudorandom signals

Abstract

The definitive characteristic of a reference phase of a pseudorandom signal is that it is uncorrelated with constant and linear signals. The existence of reference phases for pseudorandom signals, based on m sequences, is investigated, and the properties of such phases are described. Characteristic constants which relate a reference phase to others are defined through its correlation with quadratic and cubic signals. Reference phases with minimum absolute value of the characteristic constant, defined by correlation with quadratic signals, are tabulated. In the estimation of a system weighting function by crosscorrelation, use of a tabulated reference phase eliminates errors due to constant and linear drift in the system output, and minimises errors due to quadratic drift. By linear weighting of the crosscorrelation over two periods of the reference phase, errors due to constant, linear, quadratic and cubic drift may be eliminated.