Gain Imbalance (DVB-S2/S2X)
compares the gain of the I signal with the gain of the Q signal, as follows:
The effects of IQ gain imbalance are best viewed in constellation diagrams where the width of the constellation diagram is different than its height.
Gain imbalance may be a positive or negative value because it is expressed as a logarithmic value.
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 look like Quadrature Skew, and vice-versa. This occurs when the VSA is phase locked to an orientation that is different than that of the modulator.
See Also
