Hi all,

Currently i'm doing a project to prove that the concurrent short signalling
in real environment.

i am using MATLAB R2016A OS Ubuntu 14.04. USRP N210 using CBX
daughterboards. i have succesfully generate MEX function by following R.
Subramanian paper (https://github.com/80211bSDR/LinkLayer-MATLAB).

now, i'm try to run 1DTx (dtxPHYLayerVisual.m) and
1Rx(drxPHYLayerVisual.m). before running the 1DTx and 1DRx,we need to run
the command below

i )    at the DTx

DTxInitParameters
swapFreqFlag = 0; %same channel operation
codegen transceiveXXX -args

{complex(zeros(1408,1)),true,txGain,rxGain,centerFreqTx,centerFreqRx,decFactor,
intFactor,swapFreqFlag}

ii) at the DRx

DRxInitParameters
codegen transceiveXXX -args

{complex(zeros(1408,1)),true,txGain,rxGain,centerFreqTx,centerFreqRx,decFactor,
intFactor}

after complete the step above,we found errors when running the
1DTx(dtxPHYLayerVisual.m) and 1DRx (drxPHYLayerVisual.m). The error
come out from DTxPHYlayerVisual.m as below:

@ 3.06: 802.11b DATA Packet #1 Transmitted.xxxError using
coder.internal.errorIf (line 8)The input signal must be complex.Error
in comm.internal.CoarseFrequencyEstimatorBase/validateInputsImpl (line
70)      coder.internal.errorIf(isreal(x), ...Error in rffe (line 66)
ofs = step(he,ddf);Error in dtxPHYLayerVisual>dtx_3ReceiveACK (line
453)    dfr (1:halfUsrpFrameLength)= rffe(df,ft,cas,cau,cef);Error in
dtxPHYLayerVisual (line 81)        [faf,dfl,flg,nrb,rbs,st] =
dtx_3ReceiveACK(df,ft,st);

acknowledgement from the receiver. I've suspected these errors are due
to wrong declaration of IPaddress. Currently, I've setup the IP
Address DTx is 192.168.10.2 and DRx is 192.168.10.20.is our
declaration is correct or not?

I hope someone can enlighten me either it is due to the IPaddress or
other issues and can give me the solutions.

Regards,

ChongSeah

Hi Seah,

Based on the error you're getting below, the coarse frequency offset (CFO) estimator is receiving a real signal when it will accept only a complex signal.  Cast that signal to be complex before it enters the CFO estimator, and you should eliminate that error.

Best,

Mike

From: USRP-users usrp-users-bounces@lists.ettus.com on behalf of seah chong via USRP-users usrp-users@lists.ettus.com
Sent: Tuesday, September 12, 2017 12:12 AM
To: usrp-users@lists.ettus.com
Subject: [USRP-users] the transmitter cannot receive the acknowledgement from the receiver

Hi all,

Currently i'm doing a project to prove that the concurrent short signalling in real environment.

i am using MATLAB R2016A OS Ubuntu 14.04. USRP N210 using CBX daughterboards. i have succesfully generate MEX function by following R. Subramanian paper (https://github.com/80211bSDR/LinkLayer-MATLAB).

[https://avatars2.githubusercontent.com/u/17501905?v=4&s=400]https://github.com/80211bSDR/LinkLayer-MATLAB

GitHub - 80211bSDR/LinkLayer-MATLAB: This work is ...https://github.com/80211bSDR/LinkLayer-MATLAB
github.com
LinkLayer-MATLAB - This work is supported by MathWorks under the Development-Collaboration Research Grant. We would appreciate a citation to our paper when this code ...

now, i'm try to run 1DTx (dtxPHYLayerVisual.m) and  1Rx(drxPHYLayerVisual.m). before running the 1DTx and 1DRx,we need to run the command below

i )    at the DTx

DTxInitParameters
swapFreqFlag = 0; %same channel operation
codegen transceiveXXX -args {complex(zeros(1408,1)),true,txGain,rxGain,centerFreqTx,centerFreqRx,decFactor, intFactor,swapFreqFlag}

ii) at the DRx

DRxInitParameters
codegen transceiveXXX -args {complex(zeros(1408,1)),true,txGain,rxGain,centerFreqTx,centerFreqRx,decFactor, intFactor}

after complete the step above,we found errors when running the 1DTx(dtxPHYLayerVisual.m) and 1DRx (drxPHYLayerVisual.m). The error come out from DTxPHYlayerVisual.m as below:

@ 3.06: 802.11b DATA Packet #1 Transmitted.
xxx
Error using coder.internal.errorIf (line 8)
The input signal must be complex.

Error in comm.internal.CoarseFrequencyEstimatorBase/validateInputsImpl (line 70)
coder.internal.errorIf(isreal(x), ...

Error in rffe (line 66)
ofs = step(he,ddf);

Error in dtxPHYLayerVisual>dtx_3ReceiveACK (line 453)
dfr (1:halfUsrpFrameLength)= rffe(df,ft,cas,cau,cef);

Error in dtxPHYLayerVisual (line 81)
[faf,dfl,flg,nrb,rbs,st] = dtx_3ReceiveACK(df,ft,st);

I hope someone can enlighten me either it is due to the IPaddress or other issues and can give me the solutions.

Regards,

ChongSeah

thanks.it's work.

On Tue, Sep 12, 2017 at 8:10 PM, Mike McLernon Mike.McLernon@mathworks.com
wrote: