INTRODUCTION

Various aspects described herein relate to wireless communication and, more particularly but not exclusively, to reporting a power limit along with an indication of at least one constraint upon which the power limit is based.

In some wireless communication systems, a wireless communication device may use beamforming to communicate with another device or other devices. To send and/or receive a beamformed signal, a device may be equipped with an antenna subarray, a microwave lens, multiple transmit antennas, multiple receive antennas, or a combination thereof. One example is a millimeter wave (mmW) system where multiple antennas are used for beamforming (e.g., in the range of 30 GHz, 60 GHz, etc.). For example, a base station may use beamforming to communicate with different devices served by the access point. Often, the beamforming directions to these two devices are distinct. Consequently, the base station may use a first beam configuration to communicate with a first device and use a second beam configuration to communicate with a second device. In some scenarios, this communication may take place in a time-division-multiplexing (TDM) or time-division-duplexing (TDD) manner That is, the base station transmits to the first device in a first time interval and transmits to the second device subsequently in a second time interval.

FIG. 1illustrates an example of a communication system100where a mmW base station (BS)102communicates with a first mmW user equipment (UE)104and a second mmW UE106via different beamforming directions. As indicated by a set of beams108, the mmW base station102may communicate via any one of a plurality of directional beams. As indicated by a set of beams110, the first mmW UE104may communicate via any one of a plurality of directional beams. As indicated by a set of beams112, the second mmW UE106may communicate via any one of a plurality of directional beams. For example, the base station102may communicate with the first mmW UE104via a first beamforming direction114and communicate with the second mmW UE106via a second beamforming direction116.

The Federal Communications Commission (FCC) and International Commission on Non-Ionizing Radiation Protection (ICNIRP) impose exposure limits on radio frequency (RF) radiation from wireless devices. The limits are specified as a specific absorption rate (SAR) for sub-6 GHz bands (power per unit volume), and as a maximum permissible exposure (MPE) for above 6 GHz bands (power per unit area). For a user equipment (UE) or mmW base station (BS), averaging using a “duty-cycle” may be allowed.

Free space losses and other losses for systems that use millimeter (mmW) bands may be much higher than the losses for sub-6 GHz systems. Thus, a higher effective isotropic radiated power (EIRP) for transmissions is generally desired for operation in mmW bands. This is typically accomplished by using one or more antenna arrays to steer the beam in the desired direction. In these systems, a single antenna radiator could fail MPE limits, or if a beam of a handheld device is pointed towards the body or skin of a person (or some other object subject to protection), the MPE limit could be exceeded. Also, for systems that communicate via mmW and sub-6 GHz bands, SAR limits and/or MPE limits could be exceeded.

SUMMARY

The following presents a simplified summary of some aspects of the disclosure to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated features of the disclosure, and is intended neither to identify key or critical elements of all aspects of the disclosure nor to delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present various concepts of some aspects of the disclosure in a simplified form as a prelude to the more detailed description that is presented later.

In some aspects, the disclosure provides an apparatus configured for communication that includes a memory device and a processing circuit coupled to the memory device. The processing circuit is configured to: determine a transmit power limit for the apparatus; generate an indication of whether the transmit power limit is constrained by a radio frequency (RF) exposure limit; and send the transmit power limit and the indication to a second apparatus.

In some aspects, the disclosure provides a method for communication including: determining a transmit power limit for a first apparatus; generating an indication of whether the transmit power limit is constrained by a radio frequency (RF) exposure limit; and sending the transmit power limit and the indication to a second apparatus.

In some aspects, the disclosure provides an apparatus configured for communication. The apparatus including: means for determining a transmit power limit for the apparatus; means for generating an indication of whether the transmit power limit is constrained by a radio frequency (RF) exposure limit; and means for sending the transmit power limit and the indication to a second apparatus.

In some aspects, the disclosure provides a non-transitory computer-readable medium storing computer-executable code, including code to: determine a transmit power limit for a first apparatus; generate an indication of whether the transmit power limit is constrained by a radio frequency (RF) exposure limit; and send the transmit power limit and the indication to a second apparatus.

In some aspects, the disclosure provides an apparatus configured for communication that includes a memory device and a processing circuit coupled to the memory device. The processing circuit is configured to: receive a transmit power limit for a second apparatus and an indication of whether the transmit power limit is constrained by a radio frequency (RF) exposure limit; and schedule the second apparatus based on the transmit power limit and the indication.

In some aspects, the disclosure provides a method for communication for a first apparatus including: receiving a transmit power limit for a second apparatus and an indication of whether the transmit power limit is constrained by a radio frequency (RF) exposure limit; and scheduling the second apparatus based on the transmit power limit and the indication.

In some aspects, the disclosure provides an apparatus configured for communication. The apparatus including: means for receiving a transmit power limit for a second apparatus and an indication of whether the transmit power limit is constrained by a radio frequency (RF) exposure limit; and means for scheduling the second apparatus based on the transmit power limit and the indication.

In some aspects, the disclosure provides a non-transitory computer-readable medium storing computer-executable code for a first apparatus, including code to: receive a transmit power limit for a second apparatus and an indication of whether the transmit power limit is constrained by a radio frequency (RF) exposure limit; and schedule the second apparatus based on the transmit power limit and the indication.

These and other aspects of the disclosure will become more fully understood upon a review of the detailed description, which follows. Other aspects, features, and implementations of the disclosure will become apparent to those of ordinary skill in the art, upon reviewing the following description of specific implementations of the disclosure in conjunction with the accompanying figures. While features of the disclosure may be discussed relative to certain implementations and figures below, all implementations of the disclosure can include one or more of the advantageous features discussed herein. In other words, while one or more implementations may be discussed as having certain advantageous features, one or more of such features may also be used in accordance with the various implementations of the disclosure discussed herein. In similar fashion, while certain implementations may be discussed below as device, system, or method implementations it should be understood that such implementations can be implemented in various devices, systems, and methods.

