IQ Meas Spec and IQ Ref Spec (TD-SCDMA)
When TD-SCDMA Demodulation is enabled, the Comp and Comp traces shows the spectrum of the Comp and Comp signals respectively. The VSA produces the spectrum by windowing and FFTing the Comp I/Q Measured or Comp I/Q Reference signal.
The spectrum represents the signal AFTER filtering.
The VSA's demodulator removes carrier-frequency error. Therefore, in the error vector spectrum display, add the carrier-frequency error to marker readouts to obtain exact frequency information. The carrier-frequency error (Freq Err) is shown in Composite Error Summary Table (FreqErr).
By default, the VSA shows the log(dB) magnitude when IQ measured spectrum is selected. The same is true for I/Q reference.
See Also
