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LTE Waveform Transmission

Question asked by kNl on May 23, 2016
Latest reply on Jun 7, 2016 by DragosB

Hi,

 

We are trying to transmit an LTE waveform, that is produced by this example: https://wiki.analog.com/resources/tools-software/linux-software/libiio/clients/lte_example,using a no OS method identical to your example here: https://github.com/analogdevicesinc/ad9361/blob/master/sw/main.cthat is for a sinusoid signal transmission.

 

Our setup is a ZC702 and an AD-FMCOMMS5 with loopback cabling communication.

 

For the LTE waveform transmission, we use a spectrum analyzer and we receive the waveform below that the power in dBm on Y Axis is far from what we transmit. Tx_NoOS.jpeg

 

 

The transmit waveform taken from the LTE Matlab example https://wiki.analog.com/resources/tools-software/linux-software/libiio/clients/lte_example can be found below, where the Y Axis is close to 80 dBm! We were not expecting identical waveform but this difference might cause problem at the reception side. Tx_matlab.jpg

 

 

 

For your information, our LTE Tx configuration is identical to the LTE Matlab example here: https://wiki.analog.com/resources/tools-software/linux-software/libiio/clients/lte_exampleς with “slow attack” for gain control etc. The rest of the configuration of our main.c is identical to the example here, although the For your information, our LTE Tx configuration is identical to the LTE Matlab example here: https://wiki.analog.com/resources/tools-software/linux-software/libiio/clients/lte_exampleς with “slow attack” for gain control etc. The rest of the configuration of our main.c is identical to the example here: https://github.com/analogdevicesinc/ad9361/blob/master/sw/main.c,  although tx_attenuation_mdB  is changed from 10000 to 0: https://github.com/analogdevicesinc/ad9361/blob/master/sw/main.c.

 

I am asking for your advice on the particular issue related to the configuration for such a transmission.

 

Katerina

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