Re: [Discuss-gnuradio] USRP2 phase drift
Hi Matt > Even if you lock the USRP2 to an external reference, there will still be > drift relative to other things not connected to the same reference. Can you give me an example? The PLL on the daughter board is also connected with the reference clock. I hope to know which part is not connected to the reference clock. The error has the same trend for all satellites. So I think the error is not caused by the clock difference between the local clock and the GPS clock. Is there any method that I can decrease the phase drift in the USRP2 output? > The > function generator has its own clock, as does GPS. > > Matt > -- Best Regards! ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] USRP2 phase drift
I still get phase drift even with atomic external clock connected and configured in software with config_mimo(MC_WE_LOCK_TO_SMA). I tried with GPS signals and a sinusoid from the function generator as the inputs. There is phase drift in both cases. The attachment shows a picture of the phase error fluctuation. Does this problem cause by the 100 MHz main oscillator on the main board? -- Best Regards! untitled.emf Description: Binary data ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Basic questions about MIMO on USRP2
Hi all, I have several basic questions on about build a MIMO system with two USRP2s. I have my master board connect with the computer and the external clock. The slave board is connected to the master by the MIMO cable. I am working C++ and I have the SISO working now. My questions are as follows: 1 Do I need to rebuild the firmware and FPGA code for the master USRP2? 2 How I can identify which one is the master board which one is the slave in the code? 3 Do I need to call the make(interface, mac_addr_str) function twice ? 4 How can I get the mac_addr_str values for the slave and the master board ? -- Best Regards! ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Failed to set center frequency (USRP2)
Hi all, I have a problem with the USRP2 board when working with the DBSRX daughter board. I am using the " usrp2_rx_cfile.py" file to collect some data with center frequency around 1.5GHz which is within the range of this daughter board, but it fails. The USRP2 works with the RFX 1800 board with this frequency. So I am confusing. Does anyone know the reason? -- Best Regards! ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] FPGA code for USRP2
Hi All, I need to make some modifications on the USRP2 board. It seems I cannot download the code from: git clone git://git.ettus.com/ettus/fpga.git. I don't know why. Does anyone know where I can get the Verilog codes and rebuild them? -- Best Regards! ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Possible to build such a multiple input system on USRP/USRP2 ?
Hi, I want to build a multiple input system with four incoming channels based on USRP/USRP2. The incoming samples of these four channels must be synchronized and feed into one computer. The center frequencies of these four channels are different, but they are within the range of the DBSRX daughter board. My question is how many USRP/USRP2 boards I need? Are there any examples about building a multiple input system? Thanks! -- Best Regards! ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
