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Different behaviors of AD9361 FMCOMM3 RF cards

Question asked by Zeeshan on Jul 10, 2017
Latest reply on Sep 8, 2017 by sripad

Dear Sir, Madam.

I am an engineer at Uurmi systems. In January, 2017 we have purchased ‘3’ Avnet kits (https://www.xilinx.com/products/boards-and-kits/1-45sl7b.html ) which includes (Zc706 FPGA, AD9361 FMCOMMS3 RF card, and other connecting cable).

 

My goal of the project is to receive and decode MIB bits of live LTE signals in different LTE bands. Specifically, I am interested in LTE Band- 3 frequency (1830.4Mhz carrier frequency).

 

To achieve this goal, I am using Avnet kit and Mathworks LTE System toolbox. I am using (zynqRadioLTEReceiverAD9361AD9364ML.m) matlab example to configure AD9361 RF card and decode MIB bits.

After properly setting up Zynq FPGA, AD9361 RF card (part number 696662) with Mathworks LTE System toolbox, I can  sucessufully receive and decode MIB bits. In this setup I have replaced AD9361 card with another to make sure I will get same results. So, without changing the Zynq board and other configurations I just replaced AD9361 RF card (part number 696662) with another AD9361RF cards (part number 696673)

 

To my surprise, after changing AD9631 RF card I can receive signals but unable to decode MIB bits because of the poor signal strength at ADC output.

 

Same behavior is noticed by replacing third AD9361 RF card (part number 696665)

In order to be more specific I am copying RF configuration parameters, PSD plot with 2 AD9631 RF cards and time domain correlation plots.

 

RF configurations parameters:

'DeviceName':   'ZedBoard and FMCOMMS2/3/4'

'ShowAdvancedProperties':   true

'GainSource':               'Manual'

'Device':                       'Xilinx Zynq and ADI FMCOMMS2/3/4'

'sdrBlockType':             'SDRRxBlock'

'carrierBoard':             'Xilinx Zynq'

'radioBoard':               'Analog Devices FMCOMMS2/3/4'

'driverLib':          'C:\ProgramData\MATLAB\SupportPackages\R2017a\toolbox\shared\sdr\sdrplug\sdrpluginbase\host\derived\bin\win64\libmwsdrembed'

'MaxNumChannels':           2

'subDeviceList':            'zynqReceiver'

'sdrExecutionMode':         'HW'

'IPAddress':                '192.168.3.2'

'dataUDPPort':              -1

'ctrlUDPPort':              -1

'OutputDataType':           'double'

'SamplesPerFrame':          19200

'EnableBurstMode':          true

'NumFramesInBurst':         5

'DataIsComplex':            true

'NumChannels':              2

'ChannelMapping':           1

'SampleRate':               3840000

'SourceSelect':             'RF data'

'SourceConfiguration1':     1023

'BypassUserLogic':          false

'CenterFrequency':          806000000

'GainControlMode':          'Manual'

'Gain':                     50

'BasebandSampleRate':       1920000

'RxChannelPackSelect':      3

'FIRCoefficientSize':       [128;128]

'FIRCoefficients':          2x128 double

'FIRGain':                  [0;-12]

'FIRDecimInterpFactor':     [4;4]

'AnalogFilterCutoff':       [3152524;3161715]

'FilterPathRates':       2x6 double = 983040000,122880000,61440000,30720000,15360000 and 3840000

'FilterDesignTypeForTx':    'DefaultFilterFromOther'

'FilterDesignTypeForRx':    'DefaultFilter'

'EnableQuadratureTracking': true

'EnableRFDCTracking':       true

'EnableBasebandDCTracking': true

'BISTLoopbackConfig':       'No Loopback'

'BISTPRBSMode':             'PRBS Disable'

'BISTToneMode':             'Tone Disable'

'BISTToneFrequency':        'F/32'

'BISTToneLevel':            '-6'

'BISTChannelMask':          0

'DMATimeoutValue':          1

I have also made sure that ‘FIRCoefficients (2x128 double)' and above configuration parameters listed above are exactly same for 2 RF cards (AD9361 (part number 696662) working RF card and AD9361 (part number 696673) NOT working RF card)

PSD plots:

Please find below PSD plot taken with samples from AD9361 (part number 696662) working RF card

 

Please find below PSD plot taken with samples from AD9361 (part number 696673) NOT working RF card

Time domain correlation plots

Please find below time domain correlation plots taken with samples from AD9361 (part number 696662) working RF card

 

Please find below time domain correlation plots taken with samples from AD9361 (part number 696673) NOT working RF card

With this can I conclude that the two AD9361 RF cards(696673 and 696665) I received with different kits have manufacturing defect? Or I am missing something?

 

Thanks for help in advance.

 

Best regards,

Syed Zeeshan Ismail,

Senior Team Leader,

Uurmi Systems.

Hyderabad- India

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