Towards Maximum Achievable Diversity in Space, Time, and Frequency in Broadband Wireless Communications
Prof. K. J. Ray Liu
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Dr. K. J. Ray Liu
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Over the past few years, there have been many attempts to understand maximum diversity available in broadband wireless communication systems using antenna array to obtain full-diversity space-time-frequency (STF) codes for such systems. Those attempts, however, were not successful. We showed in this work for the first time that the maximum achievable diversity order with arbitrary channel power delay profile is a product of the number of delay paths, the rank of the channel temporal correlation, and the number of transmit and receive antennas.
We developed in this work two systematic STF code design methods that are able to exploit all of the available spatial, temporal and frequency diversities in broadband wireless systems. Except these two systematic STF code design methods, there is no other STF code design method existing in the literature that can guarantee to achieve the maximum achievable diversity for broadband wireless communications with an arbitrary number of transmit antennas, any memory-less modulation and arbitrary power delay profiles.
This work provides a seminal first step toward the understanding of full-diversity in MIMO-OFDM systems and systematic STF code design.
This work received the Invention of the Year Award from the University of Maryland, and a U.S. patent has been filed and is currently pending.
Links:
Research Brief: Coding Techniques for Broadband Wireless Communications
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