Search found 303 matches

by bpadalino
Wed Oct 26, 2016 10:44 am
Forum: Hardware and RF
Topic: Couple questions re: Si5338
Replies: 4
Views: 13638

Re: Couple questions re: Si5338

To answer your questions: 1) Si5338N/P/Q are fine. We should be using Si5338Q. 2) It is OTP'd. I will discuss NIOS bootstrapping a little later. 3) Is your board green or black? If it's green, then no. If it's black - then it should be a good board. Surprised you don't have some of the components on...
by bpadalino
Sun Aug 28, 2016 9:14 am
Forum: Software development
Topic: Questions from a beginner
Replies: 35
Views: 70823

Re: Questions from a beginner

The software is just in the bladerf_fft M file. Specifically, for plotting the FFT, the relevant lines are here . It's pretty simple. If you can't figure out how to remove DC here, then I am not sure I can help you much at all without doing all the work for you. Read up on direct conversion RF recei...
by bpadalino
Sat Aug 27, 2016 6:20 am
Forum: Software development
Topic: Questions from a beginner
Replies: 35
Views: 70823

Re: Questions from a beginner

There aren't any of the IQ corrections or long term DC averaging done in MATLAB. Feel free to modify the code. It should be super simple to follow - it isn't that difficult that all. The corrections worked but they aren't perfect. Getting 60dB worth of image rejection for a direct downconversion rec...
by bpadalino
Fri Aug 26, 2016 6:08 am
Forum: Software development
Topic: Questions from a beginner
Replies: 35
Views: 70823

Re: Questions from a beginner

Are you trying to use the device as a spectrum analyzer expecting spectrum analyzer like results? I guess I go back to the original question - what are you trying to solve and how good is good enough? You answered the first part - you want the tones to go away. If you want the DC spike in the middle...
by bpadalino
Thu Aug 25, 2016 10:37 am
Forum: Software development
Topic: Questions from a beginner
Replies: 35
Views: 70823

Re: Questions from a beginner

-60dB worth of image rejection is pretty good. It's not great if you're doing SSB, but do you need more than 60dB of SNR to get your signal across? I am not sure if you have an issue with DC offset or IQ imbalance, but try also looking at the time domain samples. What exactly is the issue you are tr...
by bpadalino
Mon Aug 22, 2016 10:50 am
Forum: Software development
Topic: Modifying the FPGA firmware
Replies: 1
Views: 8356

Re: Modifying the FPGA firmware

That is the correct spot to place what you want.

Nothing downstream expects anything at a certain rate so you can feel free to decimate. Just the IQ + valid is required.

You may have to change timeouts on the host side if you decimate significantly, but other than that you should be good.

Brian
by bpadalino
Sun Jul 31, 2016 9:46 pm
Forum: Software development
Topic: How to query Rx config
Replies: 3
Views: 12339

Re: How to query Rx config

You should always check the return codes of all the functions after calling them. I don't know anything about C# so I am not sure what you mean about NativeMethods.cs, but if you call it and it returns an error code - you absolutely should check it.

Sorry if this answer isn't useful.
by bpadalino
Fri Jul 29, 2016 6:49 am
Forum: Software development
Topic: How to query Rx config
Replies: 3
Views: 12339

Re: How to query Rx config

That state is maintained in the CLI itself and not in the library.

Sorry for the misunderstanding.
by bpadalino
Mon Jul 11, 2016 9:53 am
Forum: Software development
Topic: USB blaster not recognized in debug configuration
Replies: 1
Views: 8917

Re: USB blaster not recognized in debug configuration

So jtagconfig seems to see the USB Blaster device. That's good. Have you ever been able to use the Quartus tools to program the FPGA or look at SignalTap inside of the FPGA? The Quartus project doesn't live in that directory. Have you been able to successfully build and create an rbf yet? If not, I ...
by bpadalino
Fri Jun 03, 2016 3:01 pm
Forum: Hardware and RF
Topic: LMS6002D Receiving performance problem
Replies: 3
Views: 15721

Re: LMS6002D Receiving performance problem

Was the original QPSK plot after residual frequency offset recovery? I see there is no DC offset as well, so I am guessing you removed that with post processing? The offset-tuned extra sensitivity might come from the IQ imbalance going to the opposite side of the spectrum and you filtering it out in...