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Measuring EVM of Shaped-OQPSK using VSA 89601A

Question asked by jh on Jun 2, 2014
Latest reply on Jun 25, 2014 by tabbott
Is it possible to measure the EVM of a Shaped-OQPSK signal using the VSA software, 89601A?  Specifically, I am interested in measuring the EVM of a MIL-STD Shaped-OQPSK signal and an IRIG Shaped-OQPSK-TG signal.

It appears that I can measure the EVM of a standard OQPSK signal, but I do not know if this can be extended to a Shaped-OQPSK signal.  Generation of a Shaped-OQPSK signal requires implementation of a frequency pulse shaping filter, but the User Defined Filter in the VSA software does not appear to be a frequency-pulse shaping filter.  Rather, the User Defined Filter appears to filter streams of separate I and Q impulse trains.  I have not been able to figure out how to translate a frequency-pulse shaping filter to an I/Q impulse filter and am wondering if such a translation is even possible.  

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