Hello, thanks for your comments! 1. I'm very sure I've saved the correct complex data in a .txt file. the complex data use "float32" format, each complex data has 64bits. I did a lot of similar experiment with single antenna mode, so I'm sure the file data is correct. 2. How can I specify the subdev spec accordingly (A:0 B:0), just add "(A:0 B:0)" following the "Mb0: Subdev Spec"? 3. What does "L" & "S" mean exactly? ------------------ Wu Haoyang ------------------ Original ------------------ From: "usrp-users";<usrp-users@lists.ettus.com>; Date: Thu, Nov 27, 2014 06:46 PM To: "usrp-users"<usrp-users@lists.ettus.com>; Subject: Re: [USRP-users]回复： Can USRP X300 support 2*2 MIMO A couple of comments: - Are you truly saving complex data in a .txt file? Usually .txt indicates something else. The same file->throttle->Freq Sink will show the correct spectrum, right? On 11/27/2014 04:05 AM, WuHaoyang via USRP-users wrote: > version information: > UHD version: 003.007.000 - For X300 in particular, we have fixed a lot of things since 3.7.0. I recommend an update. > This is our flowgraph, Two "File Sources" include different time domain > waveforms that generated by ourselves. We try to send different signal > with two TX antennas simultaneously. To reiterate, please make sure the file data is correct. > Following picture is the configuration of USRP Sink module. - You shouldn't need to, but you might want to specify the subdev spec accordingly (A:0 B:0). > when this test case is executed, we can not see the correct wave in RX > end. It seems that only the signal in Channel0 has been send out.(we use > single RX antenna, not MIMO mode, to receive and save the TX wave, and > print the waveform using MATLAB). > > The following picture shows the front panel of X300, > > We can see the LED behave like this: > TX/RX: Red - Red means 'TX', so according to your pic, you *are* tx'ing on both channels. > REF: Green > PPS: Green, twinkle > LINK: sometimes Red, sometimes Green These are fine. > Also we can see a lot of characters "L" and "S" in GNU Radio control panel. These are not good. I wonder if the MIMO setup is too fast... Is there a chance you could try running GNU Radio master branch? Cheers, M _______________________________________________ USRP-users mailing list USRP-users@lists.ettus.com http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com ------------------ 吴浩洋 北京大学 高能效计算与应用中心 2013级 计算机系 博士 电话：+86 15210831011 Haoyang Wu PhD Candidate , Center for Energy-Efficient Computing and Applications(CECA) School of EECS, Peking University TEL:+86 15210831011

On 12/02/2014 01:35 AM, WuHaoyang via USRP-users wrote: > Hello, thanks for your comments! > > 1. I'm very sure I've saved the correct complex data in a .txt file. > the complex data use "float32" format, each complex data has 64bits. I > did a lot of similar experiment with single antenna mode, so I'm sure > the file data is correct. > > 2. How can I specify the subdev spec accordingly (A:0 B:0), just add > "(A:0 B:0)" following the "Mb0: Subdev Spec"? Just use: A:0 B:0 In the subdev spec. > > 3. What does "L" & "S" mean exactly? L = Late packet. The packet arrived with a time-spec on it, but that time had already come-and-gone when the packet arrived at the USRP S = Sequence error. usually because the network interface is dropping packets Are you doing this on a VM, rather than a naked hardware machine? > > ------------------ > Wu Haoyang > > > ------------------ Original ------------------ > *From: * "usrp-users";<usrp-users@lists.ettus.com>; > *Date: * Thu, Nov 27, 2014 06:46 PM > *To: * "usrp-users"<usrp-users@lists.ettus.com>; > *Subject: * Re: [USRP-users]??: Can USRP X300 support 2*2 MIMO > > A couple of comments: > > - Are you truly saving complex data in a .txt file? Usually .txt > indicates something else. The same file->throttle->Freq Sink will show > the correct spectrum, right? > > On 11/27/2014 04:05 AM, WuHaoyang via USRP-users wrote: > > version information: > > UHD version: 003.007.000 > > - For X300 in particular, we have fixed a lot of things since 3.7.0. I > recommend an update. > > > This is our flowgraph, Two "File Sources" include different time domain > > waveforms that generated by ourselves. We try to send different signal > > with two TX antennas simultaneously. > > To reiterate, please make sure the file data is correct. > > > Following picture is the configuration of USRP Sink module. > > - You shouldn't need to, but you might want to specify the subdev spec > accordingly (A:0 B:0). > > > when this test case is executed, we can not see the correct wave in RX > > end. It seems that only the signal in Channel0 has been send out.(we use > > single RX antenna, not MIMO mode, to receive and save the TX wave, and > > print the waveform using MATLAB). > > > > The following picture shows the front panel of X300, > > > > We can see the LED behave like this: > > TX/RX: Red > > - Red means 'TX', so according to your pic, you *are* tx'ing on both > channels. > > > REF: Green > > PPS: Green, twinkle > > LINK: sometimes Red, sometimes Green > > These are fine. > > > Also we can see a lot of characters "L" and "S" in GNU Radio control > panel. > > These are not good. I wonder if the MIMO setup is too fast... Is there a > chance you could try running GNU Radio master branch? > > Cheers, > M > > > _______________________________________________ > USRP-users mailing list > USRP-users@lists.ettus.com > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com > > > ------------------ > ??? ???? > ?????????? > 2013? ???? ?? > ??:+86 15210831011 > > Haoyang Wu > PhD Candidate , Center for Energy-Efficient Computing and > Applications(CECA) > School of EECS, Peking University > TEL:+86 15210831011 > > > _______________________________________________ > USRP-users mailing list > USRP-users@lists.ettus.com > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com