Separation of Inputs

referring to the LMS7002M internal block diagram here:, i have a question:

In the transmit side, on the right hand side of the figure, it can be clearly seen that there are two paths in each channel. Each path separately goes into a DAC each, and the following components. Clearly these are the digital signals I and Q corresponding to a frequency Wosc(the TXmix frequency).

But when you generate a signal in MATLAB and export it to LimeSDR using the command :
LMS_SendStream, in the "samples " buffer, how is I and Q data placed?

Is it like: samples = I + jQ or is it like samples = [I Q]…or some other way?

Basically does the baseband processor seperate the samples signal above into 2 independent data paths called I path and Q path?

remember, all this is in MATLAB.