US 8374096

US Patent 8374096: Method for Selecting Antennas and Beams in MIMO Wireless LANs

Title: Method for selecting antennas and beams in MIMO wireless LANs

Assignee: Freedom Patents LLC (Current Assignee), Mitsubishi Electric Research Laboratories Inc (Original Assignee), Mitsubishi Electric Corporation (Previous Assignee)

Inventors: Daqing Gu, Hongyuan Zhang, Jinyun Zhang, Andreas F. Molisch

Filing Date: 2005-11-21

Issue Date: 2013-02-12

Abstract:
A computer-implemented method for selecting antennas in a multiple-input, multiple-output (MIMO) wireless local area network (WLAN) is described. The method involves a station receiving multiple consecutively transmitted sounding packets, each corresponding to a different subset of available antennas. The station then estimates a channel matrix for each antenna subset. Following the channel matrix estimation, the station sends a frame that includes a High Throughput (HT) control field to initiate the antenna selection process. Within this HT control field, an antenna selection or beam selection indicator (ASI) field set to "1" or a Modulation Coding Scheme (MCS) Request Sequence Number (MRS) field set to "111" signifies that the MCS Selection Feedback (MFB) field is to be used for antenna selection, beam selection, or as a transmitter beam forming control (ASBFC) field. The ASBFC field further contains a command subfield and a data subfield, where the data subfield specifies the number of sounding packets transmitted.

Plain-Language Overview of Independent Claims:

Independent Claim 1:
Claim 1 describes a method for a wireless station to intelligently choose which antennas to use in a MIMO wireless network. The station first receives a series of "sounding packets", which are special transmissions that allow the station to evaluate the communication channel. Each packet in this series is transmitted using a different set of antennas than the others. After receiving these packets, the station calculates a "channel matrix" for each specific set of antennas it heard from. Once these calculations are done, the station sends a special message to initiate the antenna selection. This message is part of a "High Throughput (HT) control field." A key aspect of this message is how it indicates its purpose: if a particular "Antenna Selection Indicator (ASI)" field is set to "1" (or if another field, "MRS," is set to "111"), it signals that another field, typically used for feedback on data rates ("MCS Selection Feedback" or "MFB"), is now being used for antenna selection, beam selection, or controlling "transmitter beam forming" (ASBFC). This ASBFC field further contains a "command" part and a "data" part, with the data part specifically telling the receiving station how many sounding packets were sent. This entire process leads to the selection of the best subset of antennas based on the evaluated channel conditions.

CAFC 2026 Dockets:

A search of the CAFC 2026 dockets for patent number 8374096 did not yield any direct results at the time of this analysis (April 26, 2026). The provided search results included general information about the U.S. Court of Appeals for the Federal Circuit and scheduled cases for May and June 2026, but patent 8374096 was not explicitly listed in these schedules.