Patent ID: 6535546
Filing Date: 2003-03-18
Classification: H04B

Abstract:
Method for determining characteristics of components of a communication channel through which a payload signal is transmitted at a predetermined level, comprising:generating a first pseudo noise signal PN(t); modulating a clean carrier signal f(t) with said first pseudo noise signal PN(t) to generate a PN modulated clean carrier signal s(t); transmitting said PN modulated clean carrier signal s(t) simultaneously with said payload signal through said communication channel at a level below the level of said payload signal; receiving a receive signal sâ€²(t) corresponding to said PN modulated clean carrier signal s(t) after having travelled through said communication channel; correlating said receive signal sâ€²(t) with said first pseudo noise signal PN(t) to generate a recovered carrier signal fâ€²(t); and determining the amplitude response and the group delay of the communication channel at selected discrete frequencies on the basis of a comparison of said clean carrier signal f(t) and said recovered carrier signal fâ€²(t).