Low Complexity and Low Latency Training Assisted Channel Estimation for MIMO-OFDM Systems

We consider multiple input-multiple output orthogonal frequency division multiplexing indoor wireless communications, adopting training assisted channel estimation. We focus on the transmission of orthogonal training sequences over a generic number of spatial streams, possibly different from the number of antennas. We show how to cope with performance requirements, low latency and complexity, firstly reducing the problem to a series of easier single input-single output problems, and finally exploiting the correlation between adjacent tones to refine the previously obtained estimations. As a practical example, we consider the 802.11n ongoing standard.