ALEXANDRIA, Va., June 16 -- United States Patent no. 12,308,931, issued on May 20, was assigned to Fujitsu Ltd. (Kawasaki, Japan).

"Communication apparatus, wireless communication system, and transmission rank switching method" was invented by Kazuto Sato (Yokohama, Japan), Daisuke Jitsukawa (Adachi, Japan), Shin Hosokawa (Yokosuka, Japan) and Takato Ezaki (Yokohama, Japan).

According to the abstract* released by the U.S. Patent & Trademark Office: "A communication apparatus that communicates with a terminal device using a multi-input multi-output (MIMO) data transfer method includes: a memory; and a processor coupled to the memory and configured to: estimate a reception signal to interference ratio (SIR) of a wireless propagation path be...