The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 18, 2014
Filed:
Jan. 20, 2012
Koichi Hashimoto, Miharu, JP;
Tsuyoshi Tamaki, Machida, JP;
Koichi Hashimoto, Miharu, JP;
Tsuyoshi Tamaki, Machida, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
The selection range of antenna candidates effective for MIMO communication is widened in a base station to increase the throughput of MIMO communication. A terminal sends a sounding signal at given time intervals with the maximum transmission power or with an antenna selection transmission power threshold or larger. With this transmission, since the number of antenna candidates that receive the signal is increased at a base station in the distributed antenna system, the radio propagation channel state between the terminal and the base station apparatus is checked to select the combination of antennas having good orthogonality. Before the terminal sends the sounding signal, the terminal reserves beforehand the transmission timing of the sounding signal or performs carrier sensing to determine whether a surrounding terminal is sending a signal to avoid the collision/interference of packets of sounding signals between terminals.