TX Performance Issue (GPS-related)
Posted: Tue Jan 20, 2026 1:47 am
Hello bladeRF community, I currently have a bladeRF xA4 board.
I generated an IQ signal with a center frequency of 1580 MHz and a bandwidth of 40 MHz. I have confirmed that the values in the .bin file are within the range [-2048, 2047]. (To prevent overflow, when I quantized the samples, I limited the values to around 1800 at most.)
This signal contains GPS satellite signals and some of my own communication signals (which can be ignored). Using the exact same IQ.bin file with a USRP X310 series, GPS receivers can normally decode the GPS coordinates without any issues.
However, when I transmit this signal using the bladeRF xA4, I made sure the GPS signal is completely away from the LO leakage, and the waveform also looks normal on a spectrum analyzer.
But only a very small number of receivers are able to lock onto the GPS satellites.
What could be causing this issue?
I also tried transmitting only the GPS signal, but the result is the same.
I generated an IQ signal with a center frequency of 1580 MHz and a bandwidth of 40 MHz. I have confirmed that the values in the .bin file are within the range [-2048, 2047]. (To prevent overflow, when I quantized the samples, I limited the values to around 1800 at most.)
This signal contains GPS satellite signals and some of my own communication signals (which can be ignored). Using the exact same IQ.bin file with a USRP X310 series, GPS receivers can normally decode the GPS coordinates without any issues.
However, when I transmit this signal using the bladeRF xA4, I made sure the GPS signal is completely away from the LO leakage, and the waveform also looks normal on a spectrum analyzer.
But only a very small number of receivers are able to lock onto the GPS satellites.
What could be causing this issue?
I also tried transmitting only the GPS signal, but the result is the same.