Patent ID: 6275678
Filing Date: 2001-08-14
Classification: H04B

Abstract:
Method for determining an operating point of a non-linear amplifier 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 s'(t) corresponding to said PN modulated clean carrier signal s(t) after having traveled through said communication channel;correlating said receive signal s'(t) with said first pseudo noise signal PN(t) to generate a recovered carrier signal f'(t); anddetermining the operating point of said non-linear amplifier of the communication channel on the basis of said clean carrier signal f(t) and said recovered carrier signal f'(t);wherein said correlating of said receive signal s'(t) and said first pseudo noise signal PN(t) is achieved by delaying said first pseudo noise signal PN(t) and multiplying the delayed first pseudo noise signal PN(t) and said receive signal s'(t).