Beamforming systems having a few bits of channel state information fed
back to the transmitter benefit from low complexity decoding structures
and performances gains compared with systems that do not have channel
state feedback. Both unit rank and higher rank systems are implemented.
Substantial design effort may be avoided by following a method of using
functions formulated for space-time systems with the change that the
channel coherence time is equated to the number of transmit antennas and
the number of antennas in the space-time formulation is fixed at one.