Some results on the asymptotic downlink capacity of MIMO multi-user networks

In this contribution1, some results on the downlink
capacity of MIMO Multi-user Networks are provided when only
the scattering environment (and not the channel realization)
is known at the transmitter. Considering a multi-user system
where each terminal employs multiple antennas (including the
Base Station), asymptotic (in the number of antennas) analytical
expressions of the system capacity are presented and studied in
three different cases: equal time sharing, equal power sharing
and optimum time-power scheduling. Interestingly, based only
on the knowledge at the base station of the number of scatterers
at each receiver link and not the full instantaneous channel
realization (which can be fed back with limited overhead), one is
able to derive optimal power and time scheduling policies which
enhance the performance with respect to uniform time and power
allocation. Simulations provided in the case of a small number
of antennas confirm the asymptotic claims.