Achievable rate of MIMO systems with multi-user diversity and delayed feedback.

The effects are investigated of delayed feedback on the system achievable rate (AR) of a multi-user diversity multiple-input multiple-output (MIMO) system over uncorrelated Rayleigh fading channels in a general framework allowing for arbitrary numbers of transmit/receive antennas and various spatial combining schemes. Exact AR expressions are derived for different MIMO schemes, including the selective combining, maximum ratio combining and space-time block codes. Numerical results are presented to examine the validity of the theory. [ABSTRACT FROM AUTHOR]