Problem with persistent tx of iq data
Posted: Tue Oct 31, 2017 4:54 pm
Hello,
New to bladeRF here. I am trying to understand the effects of calibration by running baseband loopback tests and am running into a strange issue. I set up the tx/rx streams in bladerf-cli as follows:
tx config file=fm_iq_data.csv format=csv repeat=0 delay=0
rx config file=rx_txlpf_rxlpf.csv format=csv n=1000
The iq data that I provide in fm_iq_data.csv is 100 samples representing 100kHz modulating baseband signal for FM. The 100 samples correspond to one period of a 100kHz sine wave with a samplerate of 10M. I set up the samplerate and bandwidth as follows:
set bandwidth rx 2M
set samplerate rx 10M
set bandwidth tx 2M
set samplerate tx 10M
Once I set it all up, I run
tx start
The first time I do 'rx start', received IQ data seems fine; it looks like what I expect. However, when I try to receive samples a second time, I just get nonsense, really slow moving or DC like IQ data.
It seems like the first capture somehow interrupts the transmitter and tx just stops sending new data out (even though tx config shows that it is in the "Running" state). In order to get good data again, I have to stop and re-start tx. Is this a configuration issue? Am I missing a step, maybe a buffer configuration, that will allow simultaneous tx/rx in bladeRF-cli?
Thanks in advance,
--Erick
New to bladeRF here. I am trying to understand the effects of calibration by running baseband loopback tests and am running into a strange issue. I set up the tx/rx streams in bladerf-cli as follows:
tx config file=fm_iq_data.csv format=csv repeat=0 delay=0
rx config file=rx_txlpf_rxlpf.csv format=csv n=1000
The iq data that I provide in fm_iq_data.csv is 100 samples representing 100kHz modulating baseband signal for FM. The 100 samples correspond to one period of a 100kHz sine wave with a samplerate of 10M. I set up the samplerate and bandwidth as follows:
set bandwidth rx 2M
set samplerate rx 10M
set bandwidth tx 2M
set samplerate tx 10M
Once I set it all up, I run
tx start
The first time I do 'rx start', received IQ data seems fine; it looks like what I expect. However, when I try to receive samples a second time, I just get nonsense, really slow moving or DC like IQ data.
It seems like the first capture somehow interrupts the transmitter and tx just stops sending new data out (even though tx config shows that it is in the "Running" state). In order to get good data again, I have to stop and re-start tx. Is this a configuration issue? Am I missing a step, maybe a buffer configuration, that will allow simultaneous tx/rx in bladeRF-cli?
Thanks in advance,
--Erick