Throughput/Delay Measurements of Limited Feedback Beamforming in Indoor Wireless Networks

This paper investigates the tradeoff between throughput and feedback delay of limited feedback beamforming in indoor wireless channels with a practical MIMO-OFDM prototype. Past descriptions of this tradeoff are largely based on simplified models of the wireless channel. Unfortunately, wireless channel models may not accurately represent the complexities of a real wireless channel. Furthermore, system impairments, including channel estimation error, only exacerbate the problem of modeling a real wireless system. One such analytical result predicts the performance of limited feedback beamforming as an exponential function of feedback delay. This analytical result has been confirmed through Monte Carlo simulation under Rayleigh fading channel models. Through rigorous measurements and experimentation this paper both evaluates the performance of limited feedback beamforming under feedback delay and confirms the accuracy of the analytical results.