MATLAB Answers


How to use AD9361 TX RF block set in Simulink

I am using AD9361 RF blockset to simulate my FHSS code in matlab.I am unable to modulate my signal to Radio wave frequency(in GHz) using the AD9361 TX block.
The input signal is not being mixed with Local Oscillator frequency and when i check the output of TX using spectrum analyser its showing the same base band signal given in the input.
I have tried changing the filter settings of the AD9361 Tx still there is no improvement in the output.
I need help and advice to understand and solve the problem.


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1 Answer

Answer by Urmila Rajpurohith on 23 Aug 2019
 Accepted Answer

The “External LO” block is use to add noise on the LO signal of 2GHz specified in the “ad9361_tx” block mask, while the “Ideal Source” complex sine signal of 2MHz (look under the mask) is the modified input to the modular found in the subsystem “ad9361_tx/ad9361_tx/RF_TX”. The noise skirt is specified in the “External LO” block, while the bandwidth of the signal is related to the “Step size”, Tstep, found in the “ad9361_tx/ad9361_tx/RF_TX/Configuration” block. The Configuration block is also use to specify the simulation frequencies.
The “ad9361_tx/ad9361_tx/RF_TX” has three Inport blocks. The blocks “Inport_I”(real part of complex baseband) and “Inport_Q(imaginary part of complex baseband) specify that the complex sine signal resides on a DC carrier (Carrier frequency = 0). If the carrier frequency is not DC, then the complex baseband signal is handled as I+jQ. The “ad9361_tx/ad9361_tx/RF_TX/LO Signal” block specifies the LOFreq and the “ad9361_tx/ad9361_tx/RF_TX/Outport” block specifies that the desired output carrier frequency is ‘RF’. The output carrier frequency of interest should be DC+LO=LO=RF=2GHz. The original baseband signal, after system processing, will reside on this RF signal. However, a baseband signal is I=jQ where the carrier is implied but not shown.
You can follow the documentation which is provided in Add-on Manager.

  1 Comment

Thanks for the insights I will go through the documentaion

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