Mid IQ Offset (TD-SCDMA)
Mid IQ Offset (Midamble IQ Offset) indicates the relative magnitude of the midamble carrier feedthrough signal. When there is no midamble carrier feedthrough, Mid IQ offset is zero (-infinity dB).
IQ origin offset is easily seen in the constellation diagram, as shown below:
In the above illustration, "x" is the center of the constellation diagram. When "x" occurs at the origin, the IQ offset is zero. When "x" is not at the origin, the IQ offset is the magnitude of the vector (in dB) between "x" and the origin, relative to the symbol magnitude.
The midamble feedthrough shown in the symbol table is computed only at the chip times (the instant in time when symbols are detected).
See Also
