Abstract
This paper introduces a novel adaptive guard-interval scheme for multiple-input multiple-output (MIMO) orthogonal-frequency-division-multiplexing (OFDM) systems. Conventional OFDM systems set the guard-intervals large enough to combat the inter-symbol interference (ISI). However, such long guard-intervals would often lead to the severe throughput reduction. We design a non-pilot-aided channel-length estimation scheme, which does not require the additional pilot overhead, and propose a new MIMO-OFDM system built on such an adaptive prefix mechanism triggered by the feedback channel length information. Our simulations show that the proposed scheme greatly outperforms the conventional MIMO-OFDM systems. ©2009 IEEE.