Hi Anusaya,
I understand that you are interested to know about the modulation scheme used in the documentation example on CSI Feedback with Autoencoder.
The example which you were referring does not discuss the modulation scheme. The example is focused on the use of autoencoder neural network for compressing channel state information (CSI) over clustered delay channel (CDL). Upon receiving CSI parameters, the gNB node schedules downlink data transmissions with attributes such as modulation scheme, code rate, number of transmission layers, and MIMO precoding.
You could refer the reference paper mentioned in the documentation example to know more about the modulation scheme used to train the autoencoder model.
