Summary
International Symposium on Antennas and Propagation
2012
Session Number:3A2
Session:
Number:3A2-2
A Method for Controlling Phase Difference between Propagation Channels for Short-range MIMO Transmission
Kazumitsu Sakamoto, Ken Hiraga, Tomohiro Seki, Tadao Nakagawa, Kazuhiro Uehara,
pp.-
Publication Date:2012/10/29
Online ISSN:2188-5079
Summary:
We have focused on the short range MIMO (SR-MIMO) transmission that performs MIMO transmission by utilizing the length differences in the propagation channels between facing transmitting and receiving array antenna elements in short range wireless communications. We have already clarified the existence of optimum element spacing, which maximizes the channel capacity for a given distance between transceivers. For example, when there is a 90-degree phase difference between each propagation channel between transceiver antenna elements, 2�~2 SR-MIMO transmission achieves maximum channel capacity. However, in actual usage cases it is likely difficult to perform SR-MIMO transmission over optimum distances using an array antenna designed with a certain element spacing. To address the issue in this paper, we propose a phase difference control technique that adjusts the phase difference between each propagation channel to 90 degrees. This maximizes channel capacity by controlling the transmission (or received) power ratio of sub-array antenna. We also show the proposed method's effectiveness by simulation and experimental evaluation.