The general idea is to suppress symmetrical images caused by IQ imbalance in the RX path of quadrature receivers. It's composed of two subblocks: "IQ Bal Fix": This applies the actual correction. to a complex stream. The correction parameters are only magnitude/phase and the actual correction algo is the same as applied in hardware in the USRP. You can either specify the correction parameters manually on the block, or send them via 'messages'. "IQ Bal Optimize": This blocks tries to blindly detect the imbalance by minimizing the correlation between the left and right part of the spectrum. See the code for the "how it does it". The general idea is inspired from papers found on the internet and the way some SDR software achieve the same things (sdr# for eg, although there are significant differences in the actual implementation).
sudo apt install gr-iqbal (1.27 MB)
Dependências: libc6, libgcc-s1, libgnuradio-iqbalance3.9.0, libgnuradio-runtime3.10.12, libpython3.13, libstdc++6, python3, python3