we present a practical link adaptation

algorithm for MIMO-OFDM systems. The proposed solution is

based on sounding the channel periodically and choosing the

optimal mode that will maximize the throughput or energy

efficiency (EE) while satisfying the application’s quality of service

(QoS) requirements. In addition, we address practical problems

such as the computational complexity of the algorithm and

determination of sounding period by novel closed form solutions

and iterative algorithms. Realistic link level simulations confirm

that the proposed solution achieves significant improvement

over existing link adaptation algorithms when the aim is to

maximize the throughput, and provides orders of magnitude

gain in energy efficiency compared to poorly chosen fixed modes

when used for energy efficiency maximization purposes. The

resulting algorithms are implemented on a real time MIMOOFDM testbed, and we report on the experimental results.