dawsonjon
dawsonjon
Yes, it still makes sense after decimation. I've been meaning to do some measurements of mirror suppression, so we can do a before and after.
I think the best way to measure the image rejection is to tune in a strong signal (as strong as possible without saturating the op-amp), note the power in dBm,...
I was thinking of implementing automatic correction similar to the method you linked. The Mosley paper they followed on the uhsdr project describes an efficient method of estimating the imbalance...
Nice! Looks like a very efficient implementation. I will try some tests and see if it improves the performance.
Something not quite right at the moment, enabling IQ correction is making the images worse rather than better. I expect its probably a simple fix somewhere. For interest, I have...
Cool, testing it now!
I tried a few tests with the iq_corr_mosely branch, but I still couldn't see any improvements to the image rejection. I have spent a bit of time trying to see...
That's a very neat implementation. I always struggle a bit with IIR filters, especially in fixed point. Would be very interested to see how this was derived. It's fairly easy...
Yes, that's right the frequency shift is effectively rotating the spectrum in the frequency domain. The difficulty comes when we need a resolution finer than 1 bin. Its quite unusual...
Yes, I meant if it was finer than 1 bin. I'm not sure if there is anything existing that needs to be moved to the frequency domain, but we can...