Wi-fi adaptive receiver diversity and wi-fi adaptive transmit antenna selection

Abstract

Wireless communication devices (UEs) may include multiple receive (RX) chains and associated antennas, and at least one transmit (TX) chain co-located with one of the RX chains. The UE may track instant fading of the antenna gain(s) during reception of packets from an associated access point (AP) device to which the UE intends to transmit packets. The UE may also track long term antenna gain(s), using any packets received at the multiple RX chains within the UE. At a switching occasion, a decision is made by the UE whether to switch antennas. If the instant fading detection is based on packets received no later than a specified time period prior to the switching occasion, then the UE may make the switching decision based on the results of the instant fading tracking. Otherwise, the UE may make the switching decision based on the results of the long term antenna gain tracking. The wireless communication devices may also evaluate signal strength during transmission of the RX packets, and / or may evaluate a possible imbalance (gain difference) between the multiple RX chains within the wireless communication device. Signal strength detection may be enabled when non-MIMO transmissions are taking place, while imbalance detection (antenna gain comparison) may be enabled when a specified number of single-stream packets have been received. Once the decision has been made to operate in a reduced number RX path mode, decision to reactivate one or more additional RX paths may be made based on MIMO detection, a detection of a drop in signal quality, and / or upon expiration of a power save timer.

Description

technical field [0001] The present application relates to wireless communications, and more particularly to techniques for adaptive receiver diversity and antenna selection in wireless communications devices. Background technique [0002] The use of wireless communication systems is increasing rapidly. Furthermore, wireless communication technology has evolved from voice-only communication to also include data transfer, such as the Internet and multimedia content. One popular short / medium range wireless communication standard is wireless local area network (WLAN). Most of today's WLANs are based on the IEEE 802.11 standard (or simply 802.11), and are marketed under the "Wi-Fi" brand name. A WLAN network connects one or more devices to a wireless access point, which in turn provides connectivity to the wider Internet. [0003] In an 802.11 system, devices that are wirelessly connected to each other are called "stations." A wireless station may be a wireless access point (...

AI Technical Summary

Problems solved by technology

The two receiver chains can be used together to improve receiver performance, but often at the expense of using more power

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