Dear all,
In the version 1.2 of the simulator, multi user MIMO is done by techniques such as zero forcing and block diagonalization at the base station.
In the mu-mimo case, the PMI is disabled. As far as I understand the base station needs the detailed channel information in order to do ZF or BD.
How does the BS obtain this channel information from all of the users?
Base station can send pilot signals and users can estimate the channel and send feedback. However, for a large number of users , this would create a large overhead.