[USRP-users] E312 Multi-channel issues
Beeman, Isaac L.
ilbeeman at wpi.edu
Wed Jan 22 19:19:40 EST 2020
I am using the E312 to receive on both channels so I can use a dual antenna system to determine the direction the received signal is coming from. I have gotten the GPS, internal IMU working, and single channel RX working. The issue is, when I try to receive on both channels simultaneously, one of the receivers (at random?) is measuring about 20db below the other. Here is a photo of what I mean (https://imgur.com/EtzLjPO shows RX-B being the strong signal) and here is a few lines of data from a different test (showing RX-A as the strong signal):
I have tried everything I can think of: swap out antennas, swap out USRPs, try a wired test, and try different versions of UHD; but found no solution. I even tried directly adjusting for the gain difference, but that just led to a channel with significantly more noise than the other.
All my code is based off of sample code like rx_multi_samples.cpp and rx_samples_to_file.cpp, so I know that there aren't any glaring issues with my code. I also know that it isn't a direct hardware issue because both RX-A and RX-B receive fine on their own and seem to be randomly selected to be the channel receiving at full power when doing multi-channel.
Am I doing something completely wrong? I can't think of anything else to try. I was hoping to test this out in the next couple weeks, so any help would be greatly appreciated.
Here is a pastebin of my simplified code: https://pastebin.com/MNmV0CVM
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