Patent ID: 7639756
Filing Date: 2009-12-29
Classification: H03C,H04L

Abstract:
1. A method for deriving, by a computer, optimum adjustment values of an offset (I-offset) of an in-phase signal (I-signal) and an offset (Q-offset) of a quadrature signal (Q-signal) in a quadrature modulator, which is configured for quadrature modulating a carrier signal with said I-signal and with said Q-signal, output from a baseband unit, and for outputting the quadrature modulated carrier, said method comprising the steps of: said computer inputting measured values of a carrier leak level of an output of said quadrature modulator, supplied with said I-signal and the Q-signal, output from said baseband unit, for each of at least three respective different sets of set-up values of the I-offset and the Q-offset, as selected on a two-dimensional coordinate plane having I-components and Q-components as X and Y coordinates, respectively; and said computer calculating corresponding values of a carrier suppression ratio from measured values of the carrier leak level of the three sets of the set-up values of the I-offset and the Q-offset to derive optimum adjustment values of the I-offset and the Q-offset.