Hi,

I have simple question about "Measurament Filter" on VSA 89600 7.20.

I have made a QPSK modulator, but I have some problem on EVM measuramet. I applied a filter Square root to signal QPSK with 32 taps and roll-off 0.35 using the "Kaiser" window of approximation.

Setup "OFF" Receiver Filter and "Root Square" Measure Filter, comparing the signal "generated" by me and the signal generated by theoretical VSA, there are differences (on filtered signal real and simulate).

Someone knows the number of taps and the approximation window of that the VSA uses to "create" his signal to compare it to my to calcolate the EVM ?

Thanks.

Kappa.

I have simple question about "Measurament Filter" on VSA 89600 7.20.

I have made a QPSK modulator, but I have some problem on EVM measuramet. I applied a filter Square root to signal QPSK with 32 taps and roll-off 0.35 using the "Kaiser" window of approximation.

Setup "OFF" Receiver Filter and "Root Square" Measure Filter, comparing the signal "generated" by me and the signal generated by theoretical VSA, there are differences (on filtered signal real and simulate).

Someone knows the number of taps and the approximation window of that the VSA uses to "create" his signal to compare it to my to calcolate the EVM ?

Thanks.

Kappa.

Try Receiver filter: Root raised cosine

Measurement filter: Raised cosine

Alpha: 0.35

Measurement filter is the system filter used on both Tx and Rx. If your transmitter has RRC, then you need to use RRC on your receiver. The measurement has effective RC filter with both RRC's combined.

Hope this would work.

Best,

AU