IQ QuadSkew (DVB-S2/S2X)
(IQ Quadrature Skew Error) indicates the orthogonal error between the I and Q signals. Ideally, I and Q should be orthogonal (90 degrees apart). A quadrature skew error of -3 degrees means I and Q are 87 degrees apart.
For non-rectangular formats (such as 8 PSK Phase Shift Keying: A broad classification of modulation techniques where the information to be transmitted is contained in the phase of the carrier wave.), IQ gain imbalance may show up as Quadrature Skew Error and vice-versa. This occurs when the VSA is phase locked to an orientation that is different than that of the modulator.
See Also