AnsweredAssumed Answered

Getting wrong waveform in TDD mode using AD9361

Question asked by batraaman on Feb 1, 2016
Latest reply on Feb 5, 2016 by mhennerich



I am using two Ad9361 (Arradio) chips which are connected to two Altera SocKit (Cyclone V). I would like to transmit a sample sine wave from one Ad9361 to another Ad9361 so i have configured one as a transmitter and another as a receiver. I am using the Linux driver with GUI ADI IIO to configure the boards.

I don't have any problem with transmission of the data by using either TDD or FDD ensm mode. Whereas on the receiving side i am not able to receive the data correctly in TDD mode (ensm_mode RX) but in FDD mode i am able to capture the data correctly. In TDD mode i am getting the hardware gain of 71 db  at 2.4 Ghz on RX1 which means that either no data has been received or data has been received but with very low power.  On the other side while using the FDD i am  getting the hardware gain of 15 db at 2.4 Ghz and the correct waveform.


I have transmitted sinewave_0.3.mat under  FPGA settings on the ADI. I have attached the received waveform for TDD and FDD in both time and frequency domain.


For my project, I have to use TDD mode so could you please tell me that why i am getting this behaviour and how to resolve this.