Power control for wireless LAN stations

摘要

Techniques and apparatus for controlling the transmit power of an uplink (UL) signal from a user terminal in a wireless communications system in an effort to achieve some target characteristic, such as a target carrier-to-interference (C/I) ratio, at an access point (AP) are provided. In this manner, such a user terminal may help avoid or compensate for imbalances in received radio frequency (RF) power between UL signals received from multiple user terminals by the AP. For example, the transmit power at each user terminal may be controlled in an effort to achieve a target post-processing C/I ratio of 28 dB per spatial stream in an effort to reduce large power imbalances and optimize throughput per user terminal. The user terminal and the AP may compose part of a multiple-input multiple-output (MIMO) communication system utilizing spatial-division multiple access (SDMA) techniques.

主权项

1. A method for power control of an uplink (UL) signal in a wireless local area network (WLAN), the method comprising:
receiving, at a user terminal, a downlink (DL) signal from an access point (AP) of the WLAN; measuring, at the user terminal, a received signal strength of the DL signal; calculating a desired transmit power of the user terminal for transmitting the UL signal based at least on a target signal-to-noise ratio at the AP, a processing gain at the AP, and the received signal strength of the DL signal, wherein the processing gain at the AP is a function of at least one of: a number of frequencies used for transmission or a number of spatial streams; adjusting a transmit power of the UL signal to an adjusted transmit power based on the desired transmit power; encoding an indication of a value of the adjusted transmit power in a header of an UL packet; and transmitting the UL signal, at the adjusted transmit power, to the AP, wherein the UL signal includes the UL packet.