Time-averaged radio frequency (RF) exposure across tissue and / or body locations

Abstract

Certain aspects of the present disclosure provide techniques for operating a wireless communication device in accordance with radio frequency (RF) exposure across tissue and / or body locations. An example method of wireless communication by a wireless device generally includes tracking a plurality of RF exposures across a plurality of locations associated with a human body over time. The method further includes transmitting the signal at a transmit power determined based at least in part on the time-averaged RF exposure limit and the tracked RF exposure.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. patent application serial number 18 / 326,822 filed on May 31, 2023, which claims the benefit and priority of U.S. Provisional Application No. 63 / 365,696 filed on June 1, 2022, both of which are hereby expressly incorporated herein by reference in their entirety. Background Art Technical Field

[0003] Aspects of the present disclosure relate to wireless communications and, more particularly, to radio frequency (RF) exposure across tissue and / or body locations.

[0004] Related technologies

[0005] Wireless communication systems are widely deployed to provide a variety of telecommunication services, such as telephony, video, data, messaging, broadcasting, etc. Modern wireless communication devices, such as cellular phones, must generally meet radio frequency (RF) exposure limits set by domestic and international standards and regulations. To ensure compliance with the standards, such devices may undergo an extensive certification process before being shipped to the market. In order to ensure that wireless communication devices comply with the RF exposure limits, technologies have been developed that enable wireless communication devices to assess the RF exposure from the wireless communication device and adjust the transmit power of the wireless communication device accordingly to comply with the RF exposure limits. Summary of the invention

[0006] The systems, methods, and devices of the present disclosure each have several aspects, no single aspect of which is solely responsible for its desired characteristics. Without limiting the scope of the present application as expressed by the subsequent claims, some features will now be briefly discussed. After considering this discussion, and particularly after reading the section entitled "Detailed Description of the Invention," it will be understood how the features of the present disclosure provide advantages including assessment of radio frequency (RF) exposure across tissues and / or body locations (e.g., per exposure scenario and / or category).

[0007] Some aspects provide a method for wireless communication by a wireless device. The method includes tracking multiple RF exposures across multiple locations associated with a human body over time. The method also includes transmitting a signal at a transmit power determined at least in part based on a time-averaged RF exposure limit and the tracked RF exposures.

[0008] Some aspects provide an apparatus for wireless communication. The apparatus includes a memory and a processor coupled to the memory. The processor is configured to track multiple RF exposures across multiple locations associated with a human body over time and transmit a signal at a transmit power determined at least in part based on a time-averaged RF exposure limit and the tracked RF exposures.

[0009] Some aspects provide an apparatus for wireless communication. The apparatus includes means for tracking multiple RF exposures across multiple locations associated with a human body over time, and means for transmitting a signal at a transmit power determined at least in part based on a time-averaged RF exposure limit and the tracked RF exposures.

[0010] Some aspects provide a non-transitory computer-readable medium. The computer-readable medium has instructions stored thereon that, when executed by an apparatus, cause the apparatus to perform a method. The method includes tracking multiple RF exposures across multiple locations associated with a human body over time. The method also includes transmitting a signal at a transmit power determined at least in part based on a time-averaged RF exposure limit and the tracked RF exposures.

[0011] To achieve the aforementioned and related purposes, one or more aspects include the features described in full below and particularly pointed out in the claims. The following description and the accompanying drawings set forth in detail certain exemplary features of the one or more aspects. However, these features indicate only some of the various ways in which the principles of the various aspects can be employed. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order that the above-mentioned features of the present disclosure can be understood in detail, a more specific description briefly summarized above can be obtained by referring to some aspects illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only certain typical aspects of the present disclosure and are therefore not to be considered as limiting the scope thereof, as the specification may admit to other equally effective aspects.

[0013] Figure 1 is a block diagram conceptually illustrating an example wireless communication network in accordance with certain aspects of the present disclosure.

[0014] Figure 2 is a block diagram conceptually illustrating designs of example base stations (BSs) and user equipment (UEs) in accordance with certain aspects of the present disclosure.

[0015] Figure 3 is a block diagram of an example radio frequency (RF) transceiver in accordance with certain aspects of the present disclosure.

[0016] Figure 4 is a diagram illustrating an example of a normalized specific absorption rate (SAR) distribution combined with a normalized power density (PD) distribution in accordance with certain aspects of the present disclosure.

[0017] Figure 5 is a diagram illustrating a system for measuring RF exposure distribution in accordance with certain aspects of the present disclosure.

[0018] Figure 6 is a flow diagram illustrating example operations for grouping antennas by a UE to achieve RF exposure compliance in accordance with certain aspects of the present disclosure.

[0019] Figure 7 is a block diagram illustrating an example grouping of multiple antennas for a wireless communication device in accordance with certain aspects of the present disclosure.

[0020] Figure 8 is a flow diagram illustrating example operations for determining a backoff factor for an antenna group in accordance with certain aspects of the present disclosure.

[0021] Fig. 9 is a flow diagram illustrating example operations for assigning antennas to groups based on backoff factors in accordance with certain aspects of the present disclosure.

[0022] Fig.10 is a flow chart illustrating example operations for wireless communications by a UE in accordance with certain aspects of the present disclosure.

[0023] Fig.11 Diagrams illustrating example positions of wireless devices relative to a user's body in accordance with certain aspects of the present disclosure.

[0024] Fig.12 Example RF exposure time windows in accordance with certain aspects of the present disclosure are illustrated.

[0025] Fig.13 Example RF exposure settings for certain exposure scenarios and / or exposure categories according to certain aspects of the present disclosure are illustrated.

[0026] Fig.14 Various antenna groupings for exposure categories are illustrated in accordance with certain aspects of the present disclosure.

[0027] Fig.15 An example classification of RF exposure categories is illustrated.

[0028] FIG. 16A to FIG. 19B Depicted are timing diagrams of example RF exposure tracking for different exposure scenarios.

[0029] Fig. 20 is a flow diagram illustrating example operations for wireless communications by a wireless device in accordance with certain aspects of the present disclosure.

[0030] Fig.21Illustrated are communications devices that may include various components configured to perform operations for the techniques disclosed herein in accordance with certain aspects of the present disclosure.

[0031] Fig. 22 Illustrated are communications devices that may include various components configured to perform operations for the techniques disclosed herein in accordance with certain aspects of the present disclosure.

[0032] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized on other aspects without specific recitation. DETAILED DESCRIPTION

[0033] Various aspects of the present disclosure provide apparatus, methods, processing systems, and computer-readable media for complying with radio frequency (RF) exposure limits. RF exposure can be determined and / or tracked across different tissues and / or locations on a user's body. Certain examples determine and / or operate according to RF exposure limits for one or more exposure scenarios and / or categories.

[0034] In some cases, a wireless communication device may evaluate a time-averaged RF exposure within a time window during which the wireless communication device encounters different exposure scenarios. For example, during a first portion of the time window, the wireless communication device may be in a head-worn exposure scenario (e.g., exp1), and during a second portion of the time window, the wireless communication device may be in a body-worn exposure scenario (e.g., exp2). In these cases, the different exposures may be correlated within the time window of the time-averaged RF exposure limit such that the different exposures are evaluated in the same time-averaged function (e.g., f(exp1, exp2, t)) used to determine the available transmit power margin. This technique for determining the available transmit power margin may provide reduced wireless communication performance, for example, because the same RF exposure setting is applied to the time-averaged function even though different RF exposure scenarios exist.

[0035] Various aspects of the present disclosure provide techniques and apparatus for evaluating time-averaged RF exposure for each RF exposure scenario and / or RF exposure category. For example, when the exposure scenario changes from head to body wear or vice versa, the exposure from the active radio may not expose the same tissue to RF energy, so the wireless communication device can take into account or account for the change in exposure scenario when evaluating time-averaged RF exposure compliance. For example, in some configurations, the time-averaged RF exposure encountered by the head exposure scenario may be evaluated separately from the time-averaged RF exposure encountered by the limb exposure scenario, so that the RF exposure history of each RF exposure scenario is tracked and / or evaluated separately, as further described herein. RF exposure time averaging can be performed for each exposure scenario or exposure category, which can include one or more exposure scenarios, as further described herein.

[0036] Devices and techniques for achieving RF exposure compliance described herein (e.g., for each exposure scenario / category) may achieve a desired transmit power for a particular radio, antenna, and / or antenna group, for example, due to the different exposures encountered by each of the particular radio, antenna, and / or antenna group. The desired transmit power may provide desired wireless communication performance, such as increased data rate, reduced latency, and / or increased transmit range.

[0037] The following description provides an example of RF exposure compliance in a communication system, without limiting the scope, applicability or examples set forth in the claims. Without departing from the scope of the present disclosure, the functions and arrangements of the elements discussed may be changed. Each example may ignore, replace or add each procedure or component as appropriate. For example, the method described may be performed in a different order than described, and various steps may be added, omitted or combined. In addition, the features described for some examples may be combined in some other examples. For example, any number of aspects set forth herein may be used to implement a device or practice method. In addition, the scope of the present disclosure is intended to cover such a device or method practiced using other structures, functional functions or structures and functionality in addition to or different from the various aspects of the present disclosure given herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of the claims. The word "exemplary" is used herein to mean "used as an example, instance, or illustration". Any aspect described as "exemplary" herein is not necessarily interpreted as being preferred or having an advantage over other aspects.

[0038] Generally speaking, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a specific radio access technology (RAT) and may operate on one or more frequencies. RAT may also be referred to as a radio technology, an air interface, etc. Frequency may also be referred to as a carrier, a subcarrier, a frequency channel, a tone, a subband, etc. Each frequency may support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs, or may support multiple RATs.

[0039] The techniques described herein can be used for various wireless networks and radio technologies. Although various aspects may be described herein using terms commonly associated with 3G, 4G, and / or new radio (e.g., 5G NR) wireless technologies, various aspects of the present disclosure may be applied to communication systems based on other generations and / or to wireless technologies such as 802.11, 802.15, etc.

[0040] NR access can support various wireless communication services, such as enhanced mobile broadband (eMBB) targeting wide bandwidth (e.g., 80 MHz or greater), millimeter wave (mmWave) targeting high carrier frequency (e.g., 24 GHz to 53 GHz or greater), massive machine type communication MTC (mMTC) targeting non-backward compatible MTC technology, and / or mission critical services targeting ultra-reliable low latency communication (URLLC). These services may include latency and reliability specifications. These services may also have different transmission time intervals (TTIs) to meet corresponding quality of service (QoS) requirements. In addition, these services can coexist in the same subframe. NR supports beamforming and can dynamically configure beam directions. Multiple input multiple output (MIMO) transmission using precoding can also be supported as multi-layer transmission. Aggregation of multiple cells can be supported.

[0041] Example Wireless Communications Networks and Devices

[0042] Figure 1 An example wireless communication network 100 is illustrated in which aspects of the present disclosure may be performed. For example, the wireless communication network 100 may be a NR system (e.g., a 5G NR network), an Evolved Universal Terrestrial Radio Access (E-UTRA) system (e.g., a 4G network), a Universal Mobile Telecommunications System (UMTS) (e.g., a 2G / 3G network), or a Code Division Multiple Access (CDMA) system (e.g., a 2G / 3G network), or may be configured for communication according to IEEE standards such as one or more of the 802.11 standards. Figure 1 As shown, UE 120a includes an RF exposure manager 122 that enforces RF exposure compliance (eg, per exposure scenario / category), as described herein with respect to Figures 11 to 20Further described. In some examples, according to aspects of the present disclosure, RF exposure is managed among mutually exclusive antenna groups assigned to specific exposure scenarios / categories.

[0043] like Figure 1 As illustrated in , the wireless communication network 100 may include several base stations (BSs) 110a-110z (each also individually referred to herein as BS 110 or collectively referred to as BS 110) and other network entities. BS 110 may provide communication coverage for a specific geographic area (sometimes referred to as a "cell"), which may be stationary or movable depending on the location of a mobile BS. In some examples, BS 110 may be interconnected to each other and / or connected to one or more other BSs or network nodes (not shown) in the wireless communication network 100 through various types of backhaul interfaces (e.g., direct physical connections, wireless connections, virtual networks, etc.) using any suitable transport network. Figure 1 In the illustrated example, BSs 110a, 110b, and 110c may be macro BSs for macro cells 102a, 102b, and 102c, respectively. BS 110x may be a pico BS for pico cell 102x. BSs 110y and 110z may be femto BSs for femto cells 102y and 102z, respectively. A BS may support one or more cells.

[0044] BS 110 communicates with UEs 120a-120y (each also individually referred to herein as UE 120 or collectively referred to as UE 120) in the wireless communication network 100. UEs 120 (e.g., 120x, 120y, etc.) may be dispersed throughout the wireless communication network 100, and each UE 120 may be stationary or mobile. The wireless communication network 100 may also include a relay station (e.g., relay station 110r) (also referred to as a relay, etc.) that receives transmissions of data and / or other information from an upstream station (e.g., BS 110a or UE 120r) and transmits the transmissions of the data and / or other information to a downstream station (e.g., UE 120 or BS 110), or relays transmissions between UEs 120 to facilitate communication between devices.

[0045] The network controller 130 may communicate with a set of BSs 110 and provide coordination and control (e.g., via backhaul) for these BSs 110. In some cases, such as in a 5G NR system, the network controller 130 may include a centralized unit (CU) and / or a distributed unit (DU). In various aspects, the network controller 130 may communicate with a core network 132 (e.g., a 5G core network (5GC)), which provides various network functions such as access and mobility management, session management, user plane functions, policy control functions, authentication server functions, unified data management, application functions, network exposure functions, network repository functions, network slice selection functions, etc.

[0046] Figure 2 1. The BS 110a and UE 120a (eg, Figure 1 Example components of a wireless communication network 100).

[0047] At BS 110a, transmit processor 220 may receive data from data source 212 and control information from controller / processor 240. Control information may be used for physical broadcast channel (PBCH), physical control format indicator channel (PCFICH), physical hybrid ARQ indicator channel (PHICH), physical downlink control channel (PDCCH), group common PDCCH (GCPDCCH), etc. Data may be used for physical downlink shared channel (PDSCH), etc. Medium access control (MAC)-control element (MAC-CE) is a MAC layer communication structure that may be used for control command exchange between wireless nodes. MAC-CE may be carried in a shared channel such as PDSCH, physical uplink shared channel (PUSCH), or physical sidelink shared channel (PSSCH).

[0048] The processor 220 may process (e.g., encode and symbol map) data and control information to obtain data symbols and control symbols, respectively. The transmit processor 220 may also generate reference symbols such as for a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a PBCH demodulation reference signal (DMRS), and a channel state information reference signal (CSI-RS). The transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., pre-decoding) on ​​data symbols, control symbols, and / or reference symbols (where applicable), and may provide an output symbol stream to a modulator (MOD) in a transceiver 232a-232t. Each modulator in the transceiver 232a-232t may process a corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each transceiver in the transceiver 232a-232t may further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. Downlink signals from transceivers 232a-232t may be transmitted via antennas 234a-234t, respectively.

[0049] At UE 120a, antennas 252a-252r may receive downlink signals from BS 110a and may provide received signals to transceivers 254a-254r, respectively. Transceivers 254a-254r may condition (e.g., filter, amplify, downconvert, and digitize) the corresponding received signals to obtain input samples. Each demodulator (DEMOD) in transceivers 232a-232t may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. MIMO detector 256 may obtain received symbols from all demodulators in transceivers 254a-254r, perform MIMO detection on the received symbols (where applicable), and provide detected symbols. Receive processor 258 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for UE 120a to data sink 260, and provide decoded control information to controller / processor 280.

[0050] On the uplink, at the UE 120a, a transmit processor 264 may receive and process data from a data source 262 (e.g., for a physical uplink shared channel (PUSCH)) and control information from a controller / processor 280 (e.g., for a physical uplink control channel (PUCCH)). The transmit processor 264 may also generate reference symbols for a reference signal (RS) (e.g., for a sounding reference signal (SRS)). The symbols from the transmit processor 264 may be pre-decoded by a TX MIMO processor 266, if applicable, further processed by a modulator (MOD) 254a-254r in the transceiver (e.g., for SC-FDM, etc.), and transmitted to the BS 110a. At BS 110a, the uplink signal from UE 120a may be received by antenna 234, processed by demodulators in transceivers 232a-232t, detected by MIMO detector 236 (if applicable), and further processed by receive processor 238 to obtain decoded data and control information transmitted by UE 120a. Receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to controller / processor 240.

[0051] Memories 242 and 282 may store data and program codes for BS 110a and UE 120a, respectively.A scheduler 244 may schedule UEs for data transmission on the downlink and / or uplink.

[0052] The antennas 252, processors 266, 258, 264 and / or controller / processor 280 of the UE 120a and / or the antennas 234, processors 220, 230, 238 and / or controller / processor 240 of the BS 110a may be used to perform the various techniques and methods described herein. Figure 2 As shown, the controller / processor 280 of the UE 120a has an RF exposure manager 281 that enforces RF exposure compliance. In some examples, RF exposure is achieved among mutually exclusive antenna groups assigned to specific exposure scenarios / categories in accordance with various aspects described herein. Although shown at the controller / processor, other components of the UE 120a and BS 110a may be used to perform the operations described herein.

[0053] NR can use orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) on the uplink and downlink. NR can use time division duplex (TDD) to support half-duplex operation. OFDM and single carrier frequency division multiplexing (SC-FDM) divide the system bandwidth into multiple orthogonal subcarriers, which are also commonly referred to as tones, frequency bands, etc. Each subcarrier can be modulated with data. Modulation symbols can be transmitted in the frequency domain using OFDM and in the time domain using SC-FDM. The spacing between adjacent subcarriers can be fixed, and the total number of subcarriers can depend on the system bandwidth. The system bandwidth can also be divided into subbands. For example, one subband can cover multiple resource blocks (RBs).

[0054] Although relative to Figure 1 and Figure 2 UE 120a is described as communicating with a BS and / or within a network, but UE 120a may be configured to communicate / transmit directly to another UE 120 or to communicate / transmit to another wireless device without relaying the communication through a network. Figure 2 The BS 110 a illustrated in FIG. 4 and described above is an example of another UE 120 .

[0055] Example RF Transceiver

[0056] Figure 3 is a block diagram of an example RF transceiver circuit 300 according to certain aspects of the present disclosure. The RF transceiver circuit 300 includes at least one transmit (TX) path 302 (also referred to as a transmit chain) for transmitting signals via one or more antennas 306 and at least one receive (RX) path 304 (also referred to as a receive chain) for receiving signals via antenna 306. When TX path 302 and RX path 304 share antenna 306, these paths can be connected to the antenna via interface 308, which can include any of a variety of suitable RF devices, such as switches, duplexers, diplexers, multiplexers, etc.

[0057] Receiving an in-phase (I) or quadrature (Q) baseband analog signal from a digital-to-analog converter (DAC) 310, the TX path 302 may include a baseband filter (BBF) 312, a mixer 314, a driver amplifier (DA) 316, and a power amplifier (PA) 318. The BBF 312, the mixer 314, and the DA 316 may be included in one or more radio frequency integrated circuits (RFICs). For some implementations, the PA 318 may be external to the RFIC.

[0058] The BBF 312 filters the baseband signal received from the DAC 310, and the mixer 314 mixes the filtered baseband signal with a transmit local oscillator (LO) signal to convert the baseband signal of interest to a different frequency (e.g., upconvert from baseband to radio frequency). This frequency conversion process produces sum and difference frequencies between the LO frequency and the frequency of the baseband signal of interest. The sum and difference frequencies are referred to as beat frequencies. The beat frequencies are typically in the RF range, so that the signal output by the mixer 314 is typically an RF signal, which may be amplified by the DA 316 and / or by the PA 318 before being transmitted through the antenna 306. Although one mixer 314 is illustrated, several mixers may be used to upconvert the filtered baseband signal to one or more intermediate frequencies and thereafter upconvert the intermediate frequency signal to a frequency for transmission.

[0059] The RX path 304 may include a low noise amplifier (LNA) 324, a mixer 326, and a baseband filter (BBF) 328. The LNA 324, the mixer 326, and the BBF 328 may be included in one or more RFICs, which may be the same RFIC as the RFIC that includes the TX path components, or may be a different RFIC. The RF signal received via the antenna 306 may be amplified by the LNA 324, and the mixer 326 mixes the amplified RF signal with a receive local oscillator (LO) signal to convert the RF signal of interest to a different baseband frequency (e.g., down-convert). The baseband signal output by the mixer 326 may be filtered by the BBF 328 before being converted to a digital I or Q signal by an analog-to-digital converter (ADC) 330 for digital signal processing.

[0060] Some transceivers may use a frequency synthesizer with a voltage controlled oscillator (VCO) to generate a stable, tunable LO with a specific tuning range. Thus, the transmit LO may be generated by a TX frequency synthesizer 320, which may be buffered or amplified by an amplifier 322 before being mixed with the baseband signal in a mixer 314. Similarly, the receive LO may be generated by an RX frequency synthesizer 332, which may be buffered or amplified by an amplifier 334 before being mixed with the RF signal in a mixer 326.

[0061] The controller 336 may direct the operation of the RF transceiver circuit 300, such as transmitting signals via the TX path 302 and / or receiving signals via the RX path 304. The controller 336 may be a processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof. The memory 338 may store data and program code for operating the RF transceiver circuit 300. The controller 336 and / or the memory 338 may include control logic. In some cases, the controller 336 may determine a time-averaged RF exposure based on the transmit power level applied to the TX path 302 (e.g., a certain gain level at the PA 318) to set a transmit power level that complies with RF exposure limits specified by domestic regulations and international standards, as further described herein.

[0062] Example RF Exposure

[0063] RF exposure can be expressed in terms of specific absorption rate (SAR), which measures the energy absorbed per unit mass of human tissue and may have units of watts per kilogram (W / kg). RF exposure can also be expressed in terms of power density (PD), which measures the energy absorbed per unit area and may have units of mW / cm 2 In some cases, a maximum permissible exposure (MPE) limit (in the form of PD) may be imposed on wireless communication devices using transmit frequencies above 6 GHz. MPE limits are area-based exposure regulatory metrics, such as energy density limits, which are defined as the number X (Watts per square meter (W / m2) averaged over a defined area and time-averaged over a frequency-dependent time window). 2 )) to prevent hazardous human exposure represented by changes in tissue temperature.

[0064] SAR may be used to assess RF exposure for transmission frequencies less than 6 GHz, which covers wireless communication technologies such as 2G / 3G (e.g., CDMA), 4G (e.g., LTE), 5G (e.g., NR in the 6 GHz band), IEEE 802.11ac, etc. PD may be used to assess RF exposure for transmission frequencies above 6 GHz, which covers wireless communication technologies such as IEEE 802.11ad, 802.11ay, 5G in the millimeter wave band, etc. Therefore, different metrics may be used to assess RF exposure for different wireless communication technologies.

[0065] A wireless communication device (e.g., UE 120) may use multiple wireless communication technologies to send signals simultaneously. For example, a wireless communication device may use a first wireless communication technology (e.g., 3G, 4G, 5G, etc.) operating at or below 6 GHz and a second wireless communication technology (e.g., millimeter wave 5G in the 24 GHz to 60 GHz band, IEEE 802.11ad or 802.11ay) operating above 6 GHz to send signals simultaneously. In some aspects, a wireless communication device may use a first wireless communication technology (e.g., 3G, 4G, 5G, IEEE 802.11ac, etc. in the sub-6 GHz band) (where RF exposure is measured in SAR) and a second wireless communication technology (e.g., 5G, IEEE 802.11ad, 802.11ay, etc. in the 24 GHz to 60 GHz band) (where RF exposure is measured in PD) to send signals simultaneously. As used herein, sub-6 GHz frequency bands may include frequency bands from 300 MHz to 6,000 MHz in some examples, and may include frequency bands within the range of 6,000 MHz and / or 7,000 MHz in some examples.

[0066] To assess RF exposure from transmissions using a first technology (e.g., 3G, 4G, 5G, IEEE 802.11ac, etc. in a sub-6 GHz band), the wireless communication device may include stored in a memory (e.g., Figure 2 Memory 282 or Figure 3 The wireless communication device may include a plurality of SAR values ​​and / or distributions for the first technology in a memory 338 of the wireless communication device. Each of the SAR values ​​and / or distributions may correspond to a respective one of a plurality of transmission scenarios for the first technology supported by the wireless communication device. The transmission scenario may correspond to an antenna (e.g., Figure 2 Antennas 252a to 252r or Figure 3 The SAR may be stored at a plurality of locations, such as the antenna 306, frequency band, channel, and / or body position, as further discussed below. In some examples, the stored SAR includes a single value (e.g., a peak value determined based on the following description, or a sum of peak values).

[0067] The SAR values ​​and / or distributions (also referred to as SAR maps) for each transmission scenario may be generated based on measurements (e.g., electric field measurements) performed in a test lab using a human body model. Once generated, they are stored in a memory for use by a processor (e.g., Figure 2 Processor 280 or Figure 3 The controller 336 of the SAR profile can assess RF exposure in real time, as discussed further below. Each SAR profile may include a set of SAR values, where each SAR value may correspond to a different location (e.g., on a human body model). Each SAR value may include a SAR value averaged over a mass of 1 g or 10 g at the corresponding location.

[0068] The SAR values ​​in each SAR distribution correspond to a particular transmit power level (e.g., the transmit power level at which the SAR values ​​were measured in a test lab). Since SAR scales with transmit power level, the processor can scale the SAR values ​​or distribution for any transmit power level by multiplying each SAR value (e.g., in the SAR distribution) by the following transmit power scaler:

[0069]

[0070] Among them, Tx c is the current transmit power level of the corresponding transmit scenario, and Tx SAR is the transmit power level that corresponds to the SAR value (eg, the transmit power level at which the SAR value was measured in a test laboratory).

[0071] As discussed above, the wireless communication device may support multiple transmission scenarios for the first technology. In some aspects, the transmission scenario may be specified by a parameter set. The parameter set may include one or more of the following: antenna parameters indicating one or more antennas (i.e., active antennas) for transmission, band parameters indicating one or more frequency bands (i.e., active bands) for transmission, channel parameters indicating one or more channels (i.e., active channels) for transmission, body position parameters indicating the position of the wireless communication device relative to the user's body position (head, torso, away from the body, etc.) (e.g., device state index (DSI)), exposure category and / or other parameters. In the case where the wireless communication device supports a large number of transmission scenarios, it may be very time-consuming and expensive to perform measurements for each transmission scenario in a test environment (e.g., a test laboratory). In order to reduce the test time, measurements may be performed for a subset of the transmission scenarios to generate SAR values ​​and / or distributions for the subset of the transmission scenarios. In this example, the SAR value and / or distribution of each transmission scenario in the remaining transmission scenarios may be generated by combining two or more of the SAR values ​​and / or distributions of the subset of the transmission scenarios, as further discussed below.

[0072] For example, SAR measurements may be performed for each of the antennas to generate a SAR value or distribution for each of the antennas. In this example, the SAR value or distribution of a transmission scenario in which two or more antennas are active may be generated by combining the SAR values ​​or distributions of the two or more active antennas.

[0073] For another example, SAR measurement may be performed for each of the multiple frequency bands to generate a SAR value or distribution for each of the multiple frequency bands. In this example, the SAR value or distribution of a transmission scenario in which two or more frequency bands are active may be generated by combining the SAR values ​​or distributions of the two or more active frequency bands.

[0074] In certain aspects, the SAR distribution may be normalized relative to the SAR limit by dividing each SAR value in the SAR distribution by the SAR limit. In this case, when the normalized SAR value is greater than 1, the normalized SAR value exceeds the SAR limit, and when the normalized SAR value is less than 1, the normalized SAR value is below the PD limit. In these aspects, each PD distribution in the SAR distribution stored in the memory may be normalized relative to the SAR limit. Similarly, a single or individual SAR value may be normalized relative to the SAR limit.

[0075] In certain aspects, a normalized SAR value or distribution for a transmission scenario may be generated by combining two or more normalized values ​​or SAR distributions. For example, a normalized SAR value or distribution for a transmission scenario in which two or more antennas are active may be generated by combining the normalized SAR values ​​or distributions of two or more active antennas. In the case where different transmit power levels are used for active antennas, the normalized SAR value or distribution of each active antenna may be scaled by the corresponding transmit power level before combining the normalized SAR values ​​or distributions of the active antennas. The normalized SAR value or distribution for simultaneous transmission from multiple active antennas may be given by:

[0076]

[0077] SAR lim is the SAR limit, SAR norm_combined is the normalized SAR value or distribution of the combination of simultaneous transmissions from active antennas, i is the index of the active antenna, and SAR i is the SAR value or distribution of the i-th active antenna, Tx i is the transmit power level of the ith active antenna, Tx SARi is the transmitted power level of the SAR distribution of the i-th active antenna, and K is the number of active antennas.

[0078] Formula (2) can be rewritten as follows:

[0079]

[0080] SAR norm_i is the normalized SAR value or distribution of the i-th active antenna. In the case of using multiple active antennas for simultaneous transmission at the same transmission frequency (e.g., multiple-input multiple-output (MIMO)), the combined normalized SAR value or distribution can be obtained by summing the square roots of the individual normalized SAR values ​​or distributions and calculating the square of the sum, as given by the following formula:

[0081]

[0082] As another example, normalized SAR values ​​or distributions for different frequency bands may be stored in a memory. In this example, a normalized SAR distribution for a transmission scenario in which two or more frequency bands are active may be generated by combining the normalized SAR distributions for two or more active frequency bands. In the case where the transmit power levels are different for the active frequency bands, the normalized SAR value or distribution for each of the active frequency bands may be scaled by the corresponding transmit power level before combining the normalized SAR values ​​or distributions for the active frequency bands. In this example, the combined SAR value or distribution may also be calculated using formula (3a), where i is the index of the active frequency band, and SAR is norm_i is the normalized SAR value or distribution of the ith active frequency band, Tx i is the transmit power level of the ith active band, and Tx SARi is the normalized SAR value or distributed transmit power level of the ith active frequency band.

[0083] To assess RF exposure from transmissions using a second technology (e.g., 5G in the 24 to 60 GHz band, IEEE 802.11ad, 802.11ay, etc.), the wireless communication device may include stored in a memory (e.g., Figure 2 Memory 282 or Figure 3 The wireless communication device may include a plurality of PD values ​​and / or distributions for the second technology in a memory 338 of the wireless communication device. Each of the PD values ​​or distributions may correspond to a respective one of a plurality of transmission scenarios for the second technology supported by the wireless communication device. The transmission scenario may correspond to an antenna (e.g., Figure 2 Antennas 252a to 252r or Figure 3 The stored PD may include various combinations of antennas 306, frequency bands, channels, and / or body positions, as discussed further below. In some examples, the stored PD includes a single value (e.g., a peak value determined based on the description below, or a sum of peak values).

[0084] The PD values ​​and / or distributions (also referred to as PD maps) for each transmission scenario may be generated based on measurements (e.g., electric field measurements) performed in a test lab using a human body model. Once generated, they are stored in a memory to enable a processor (e.g., Figure 2 Processor 280 or Figure 3 The controller 336 of the device can assess RF exposure in real time, as discussed further below. Each PD distribution may include a set of PD values, where each PD value may correspond to a different location (e.g., on a human body model).

[0085] The PD values ​​in each PD distribution correspond to a specific transmit power level (e.g., the transmit power level at which the PD values ​​were measured in a test lab). Since PD scales with transmit power level, the processor can scale the PD values ​​or distribution for any transmit power level by multiplying each PD value (e.g., in a PD distribution) by the following transmit power scaler:

[0086]

[0087] Among them, Tx c is the current transmit power level of the corresponding transmit scenario, and Tx PD is the transmit power level corresponding to the PD value (eg, the transmit power level at which the PD value was measured in a test lab).

[0088] As discussed above, the wireless communication device may support multiple transmission scenarios for the second technology. In some aspects, the transmission scenario may be specified by a parameter set. The parameter set may include one or more of the following: antenna parameters indicating one or more antennas (i.e., active antennas) for transmission, band parameters indicating one or more frequency bands (i.e., active bands) for transmission, channel parameters indicating one or more channels (i.e., active channels) for transmission, body position parameters (e.g., DSI) indicating the position of the wireless communication device relative to the user's body position (head, trunk, away from the body, etc.), exposure categories and / or other parameters. In the case where the wireless communication device supports a large number of transmission scenarios, it may be very time-consuming and expensive to perform measurements for each transmission scenario in a test environment (e.g., a test laboratory). In order to reduce the test time, measurements may be performed for a subset of the transmission scenario to generate a PD value and / or distribution of the subset of the transmission scenario. In this example, the PD value and / or distribution of each transmission scenario in the remaining transmission scenarios can be generated by combining two or more of the PD value and / or distribution of the subset of the transmission scenario, as further discussed below.

[0089] For example, PD measurements may be performed for each of the antennas to generate a PD value or distribution for each of the antennas. In this example, a PD value or distribution for a transmission scenario in which two or more antennas are active may be generated by combining the PD values ​​or distributions of two or more active antennas.

[0090] For another example, PD measurement may be performed for each of the multiple frequency bands to generate a PD value or distribution for each of the multiple frequency bands. In this example, a PD value or distribution for a transmission scenario in which two or more frequency bands are active may be generated by combining the PD values ​​or distributions of the two or more active frequency bands.

[0091] In certain aspects, the PD distribution can be normalized relative to the PD limit by dividing each PD value in the PD distribution by the PD limit. In this case, when the normalized PD value is greater than 1, the normalized PD value exceeds the PD limit, and when the normalized PD value is less than 1, the normalized PD value is below the PD limit. In these aspects, each PD distribution in the PD distribution stored in the memory can be normalized relative to the PD limit. Similarly, a single or individual PD value can be normalized relative to the PD limit.

[0092] In some aspects, a normalized PD value or distribution for a transmission scenario may be generated by combining two or more normalized PD values ​​or distributions. For example, a normalized PD value or distribution for a transmission scenario in which two or more antennas are active may be generated by combining the normalized PD values ​​or distributions of two or more active antennas. In the case where different transmit power levels are used for active antennas, the normalized PD value or distribution of each active antenna may be scaled by the corresponding transmit power level before combining the normalized PD values ​​or distributions of the active antennas. The normalized PD value or distribution for simultaneous transmission from multiple active antennas may be given by:

[0093]

[0094] Among them PD lim is the PD limit, PD norm_combined is the normalized PD value or distribution of the combination of simultaneous transmissions from active antennas, i is the index of the active antenna, and PD i is the PD value or distribution of the i-th active antenna, Tx i is the transmit power level of the ith active antenna, Tx PDi is the transmit power level of the PD distribution of the i-th active antenna, and L is the number of active antennas.

[0095] Formula (5) can be rewritten as follows:

[0096]

[0097] Among them PD norm_i is the normalized PD value or distribution of the ith active antenna. In the case of using multiple active antennas for simultaneous transmission at the same transmission frequency (e.g., MIMO), the combined normalized PD value or distribution can be obtained by summing the square roots of the individual normalized PD values ​​or distributions and calculating the square of the sum, as given by the following formula:

[0098]

[0099] As another example, the normalized PD values ​​or distributions for different frequency bands may be stored in a memory. In this example, a normalized PD value or distribution for a transmission scenario in which two or more frequency bands are active may be generated by combining the normalized PD distributions for two or more active frequency bands. In the case where the transmit power levels are different for the active frequency bands, the normalized PD value or distribution for each of the active frequency bands may be scaled by the corresponding transmit power level before combining the normalized PD values ​​or distributions for the active frequency bands. In this example, the combined PD value or distribution may also be calculated using formula (6a), where i is the index of the active frequency band, PD norm _ i is the normalized PD value or distribution of the ith active band, Tx i is the transmit power level of the ith active band, and Tx PDi is the normalized PD value or distributed transmit power level of the ith active band.

[0100] Example RF Exposure Combinations

[0101] As discussed above, the UE 120 may transmit signals simultaneously using a first technology (e.g., 3G, 4G, IEEE 802.11ac, etc.) and a second technology (e.g., 5G, IEEE 802.11ad, etc.), wherein the RF exposure is measured using different metrics for the first technology and the second technology (e.g., SAR for the first technology and PD for the second technology). In this case, the processor 280 may determine a first maximum allowable power level for the first technology and a second maximum allowable power level for the second technology for transmission that complies with the RF exposure limit in a future time slot. During the future time slot, the transmission power levels for the first technology and the second technology are constrained (i.e., defined) by the determined first maximum allowable power level and the second maximum allowable power level, respectively, to ensure compliance with the RF exposure limit, as further described below. In the present disclosure, unless otherwise stated, the term "maximum allowable power level" refers to the "maximum allowable power level" specified by the RF exposure limit. It should be understood that the "maximum allowable power level" is not necessarily equal to the absolute maximum power level that complies with the RF exposure limit, and may be less than the absolute maximum power level that complies with the RF exposure limit (e.g., to provide a safety margin). The "maximum allowed power level" may be used to set a power level limit for transmissions at the transmitter such that the transmitted power level is not allowed to exceed the "maximum allowed power level" to ensure RF exposure compliance. Certain examples below (in this section and others) are described with respect to SAR and / or PD distributions. However, it should be understood that distributions may not be used, and in most such examples, individual SAR or PD values ​​may be utilized.

[0102] The processor 280 may determine the first maximum allowable power level and the second maximum allowable power level as follows. The processor may determine a normalized SAR distribution of the first technology at a first transmit power level, determine a normalized PD distribution of the second technology at a second transmit power level, and combine the normalized SAR distribution with the normalized PD distribution to generate a combined normalized RF exposure distribution (hereinafter referred to as a combined normalized distribution). The value at each location in the combined normalized distribution may be determined by combining the normalized SAR value at the location with the normalized PD value at the location or for another technology.

[0103] The processor 280 may then determine whether the first transmit power level and the second transmit power level comply with the RF exposure limit by comparing the peak value in the combined normalized distribution to 1. If the peak value is equal to or less than 1 (i.e., the condition ≤ 1 is satisfied), the processor 280 may determine that the first transmit power level and the second transmit power level comply with the RF exposure limit (e.g., SAR limit and PD limit) and use the first transmit power level and the second transmit power level as the first maximum allowable power level and the second maximum allowable power level, respectively, during future time slots. If the peak value is greater than 1, the processor 280 may determine that the first transmit power level and the second transmit power level do not comply with the RF exposure limit. The condition for RF exposure compliance using simultaneous transmission of the first and second technologies may be given by the following formula:

[0104] SAR norm +PD norm ≤1 (7).

[0105] Figure 4 4 is a diagram illustrating a normalized SAR distribution 410 and a normalized PD distribution 420 , wherein the normalized SAR distribution 410 and the normalized PD distribution 420 are combined to generate a combined normalized distribution 430 . Figure 4 Also shown is the condition that the peak value in the combined normalized distribution 430 is equal to or less than 1 to achieve RF exposure compliance. Although each of the distributions 410, 420, and 430 is Figure 4 , but it should be understood that the present disclosure is not limited to this example.

[0106] The normalized SAR distribution in equation (7) can be generated by combining two or more normalized SAR distributions as described above (e.g., for a transmit scenario using multiple active antennas). Similarly, the normalized PD distribution in equation (7) can be generated by combining two or more normalized PD distributions as described above (e.g., for a transmit scenario using multiple active antennas). In this case, the RF exposure compliance condition in equation (7) can be rewritten as follows using equations (3a) and (6a):

[0107]

[0108] For the MIMO case, equations (3b) and (6b) may be combined instead. As shown in equation (8), the combined normalized distribution may be a function of the transmit power level of the first technology and the transmit power level of the second technology. All points in the combined normalized distribution should satisfy the normalization limit of 1 in equation (8). In addition, when the SAR and PD distributions are combined, the SAR and PD distributions may be spatially aligned or aligned with their peak locations so that the combined distribution given by equation (8) represents the combined RF exposure for a given location of the human body.

[0109] Example RF Exposure Measurement

[0110] As discussed above, UE 120 may transmit signals simultaneously using a first technology (e.g., 3G, 4G, IEEE 802.11ac, etc.) and a second technology (e.g., 5G, IEEE 802.11ad, etc.), wherein RF exposure is measured using different metrics for the first technology and the second technology (e.g., SAR for the first technology and PD for the second technology). RF exposure measurements may be performed differently for each transmit scenario and include, for example, electric field measurements using a human body model. RF exposure distributions (simulated and / or measured) may then be generated for each transmit antenna / configuration (beam) (as described above) on all evaluation surfaces / positions at all locations.

[0111] Figure 5 is a diagram illustrating an example system 500 for measuring RF exposure values ​​or distributions according to certain aspects of the present disclosure. As shown, the RF exposure measurement system 500 includes a processing system 502, a robotic RF probe 504, and a human body model 506. The RF exposure measurement system 500 can perform RF measurements in various transmission scenarios and / or exposure scenarios associated with the UE 120. In some examples, these measurements can be used to evaluate the appropriate backoff factor for the transmit power of the antenna 252 that complies with one or more RF exposure limits. In other words, the UE 120 can transmit electromagnetic radiation at various transmit powers via the antenna 252, and the RF exposure measurement system 500 can perform RF measurements via the robotic RF probe 504 (e.g., to determine the backoff factor for the antenna 252).

[0112] The processing system 502 may include a processor 508 coupled to a memory 510 via a bus 512. The processing system 502 may be a computing device, such as a computer. The processor 508 may include a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. For example, the processor 508 may communicate with the robotic RF probe 504 via an interface 514 (such as a computer bus interface) so that the processor 508 can obtain RF measurements made by the robotic RF probe 504 and control the position of the robotic RF probe 504 relative to the human body model 506.

[0113] The memory 510 may be configured to store instructions (e.g., computer executable code) that, when executed by the processor 508, cause the processor 508 to perform various operations. For example, the memory 510 may store instructions for obtaining RF exposure profiles associated with various RF exposure / transmission scenarios and / or adjusting the position of the robotic RF probe 504.

[0114] The robotic RF probe 504 may include an RF probe 516 coupled to a robotic arm 518. In various aspects, the RF probe 516 may be a dosimetry probe capable of measuring RF exposure at various frequencies, such as sub-6 GHz bands and / or millimeter wave bands. The RF probe 516 may be positioned by the robotic arm 518 in various positions (as indicated by dashed arrows) to capture electromagnetic radiation emitted by the antenna 252 of the UE 120. The robotic arm 518 may be a six-axis robot capable of performing precise movements to position the RF probe 516 to the location of the maximum electromagnetic field generated by the UE 120 (on the human body model 506). In other words, the robotic arm 518 may provide six degrees of freedom when positioning the RF probe 516 relative to the antenna 252 of the UE 120 and / or the human body model 506.

[0115] The human body model 506 may be a specific anthropomorphic human body model with simulated human tissue. For example, the human body model 506 may include one or more fluids that simulate human tissue of the head, body, and / or limbs. The human body model 506 may simulate human tissue to determine the maximum permissible transmit power of the antenna 252 that complies with various RF exposure limits.

[0116] Although Figure 5 The examples depicted in are described herein with respect to obtaining RF exposure values ​​or distributions with a robotic RF probe to facilitate understanding, but aspects of the present disclosure may also be applied to other suitable RF probe architectures, such as using multiple fixed RF probes positioned at various locations along the human body model 506.

[0117] Example Transmit Antenna Grouping

[0118] A multi-mode / multi-band UE has multiple transmit antennas that can transmit simultaneously in frequency bands below 6 GHz and frequency bands above 6 GHz (such as mmWave bands). As described herein, RF exposure in frequency bands below 6 GHz can be evaluated in terms of SAR, and RF exposure in frequency bands above 6 GHz can be evaluated in terms of PD. Due to regulations regarding simultaneous exposure, wireless communication devices can limit the maximum transmit power for both frequency bands below 6 GHz and frequency bands above 6 GHz.

[0119] In some cases, although the antennas may be positioned in different locations throughout the UE, the time averaging algorithm for RF exposure compliance may assume that all transmit antennas are collocated in a central location on the UE. Under this assumption, the total transmit power of all transmit antennas may be limited regardless of the actual exposure scenario (e.g., head exposure, body exposure, or limb exposure) of the individual antennas. For example, it is assumed that the user's hand covers the position of the collocation model, while a particular antenna is not covered by the user's hand. That is, the contribution of the antenna to RF exposure may vary depending on the exposure position. Implementing the collocation model may result in limiting the transmit power of a particular antenna that is not actually covered by the user's hand. That is, the assumption of collocation of transmit antennas for RF exposure compliance may provide unnecessarily low transmit power, which may affect uplink performance, such as uplink data rate, uplink carrier aggregation, and / or uplink connectivity at the cell edge.

[0120] Various aspects of the present disclosure provide various techniques for grouping antennas to determine RF exposure compliance, for example, on a group basis. In various aspects, antenna groups may be defined and / or operated so as to be mutually exclusive with respect to RF exposure. RF exposure compliance and corresponding transmit power levels may be determined separately for each antenna group. Antenna grouping as described herein may enable relatively high transmit power for a particular antenna group. Antenna grouping may refer to the specific assignment (or grouping) of antennas into separate antenna groups. Higher transmit power may provide desired uplink performance, such as desired uplink data rates, uplink carrier aggregation, and / or uplink connectivity at the cell edge.

[0121] In some aspects, multiple antenna groups are defined. Each antenna group may include one or more antennas. For example, antenna 252a may be classified into a first antenna group, and antenna 252t may be classified into a second antenna group. In some aspects, each antenna array (e.g., each phased array) is placed in a different group. These groups may be defined manually, for example, by a designer or test operator, or automatically, for example, by an algorithm that operates before, during, or during device initialization. These groups may be established based on physical location (as described in more detail below), operating frequency, form factor, related methods for calculating RF exposure, etc.

[0122] Figure 6 600 for grouping antennas to achieve RF exposure compliance in accordance with certain aspects of the present disclosure. Operation 600 may be performed, for example, by a processing system including a UE (e.g., UE 120a in wireless communication network 100), an RF exposure measurement system (e.g., RF exposure measurement system 500), and / or a computing device (such as a computer). Operation 600 may be implemented as a processor ( Figure 2 The controller / processor 280 and / or Figure 5 In addition, the signal transmission and reception performed by the UE or the RF exposure test system in operation 600 may be performed by one or more antennas (e.g., Figure 2 Antenna 252 and / or Figure 5 In some aspects, the sending and / or receiving of signals by the UE may be implemented via a bus interface that obtains and / or outputs signals of one or more processors (eg, controller / processor 280).

[0123] Operations 600 may begin at block 602, where a processing system may determine (eg, generate and / or receive) a signal for use with a wireless communication device (eg, Figure 5 6. At block 604, the processing system may assign the plurality of transmit antennas to a plurality of antenna groups based on the RF exposure distribution. Optionally, at block 606, the UE and / or the processing system may determine a backoff factor for at least one of the plurality of antenna groups, e.g., the backoff factor being associated with a particular exposure / transmission scenario. At block 608, the UE may transmit from at least one antenna in at least one of the plurality of antenna groups using a transmit power level based on the backoff factor.

[0124] In certain aspects, assigning the plurality of transmit antennas to the plurality of antenna groups at block 604 may involve the processing system determining a backoff factor for each of the antenna groups, e.g., as described herein with respect to Figure 8 As further described herein, a backoff factor may be a specific number, such as a number in the range of 0 to 1, that represents a fraction (or portion) of a maximum transmit power level supported by the UE. For example, the processing system may generate a normalized distribution of the RF exposure distribution, generate a normalized composite mapping of the normalized distribution for each antenna group in the antenna groups, and generate a sum of the normalized composite mappings for all antenna groups based on the backoff factor associated with each antenna group in the antenna groups.

[0125] In various aspects, the normalized distribution may be generated by dividing the RF exposure distribution by the maximum RF exposure value for the corresponding transmit antenna configuration, e.g., as described herein with respect to block 802. In various aspects, the normalized composite map may be generated by selecting a maximum value in the normalized distribution as the normalized composite map for each of the antenna groups, e.g., as described herein with respect to block 804.

[0126] In certain aspects, the sum of the normalized composite maps may be generated by multiplying the normalized composite map for each antenna group by an associated backoff factor to generate a weighted normalized composite map for each antenna group, and adding the weighted normalized composite maps together, e.g., as described herein with respect to block 808. In certain aspects, at least one of the backoff factors may be adjusted and applied to computing the sum of the normalized composite maps until the sum of the normalized composite maps is less than or equal to a first threshold (e.g., 1.0). That is, the backoff factor associated with each antenna group may be updated and applied to computing the normalized composite map until the sum of the normalized composite maps is less than or equal to the first threshold.

[0127] In some cases, the processing system may assign each of the plurality of transmit antennas to one of the plurality of antenna groups based on the RF exposure distribution such that there are no transmit antennas in the plurality of antenna groups. In some cases, the processing system may assign each of the plurality of transmit antennas to one of the plurality of antenna groups based on the RF exposure distribution such that there is at least one transmit antenna in the plurality of antenna groups.

[0128] In various aspects, at block 604, multiple transmit antennas may be assigned to multiple antenna groups based on the determined backoff factor values, e.g., as described herein with respect to Fig. 9 If one of the backoff factors is less than a second threshold (e.g., 0.5), the transmit antennas may be reallocated or regrouped. For example, the processing system may determine a backoff factor for a first grouping of antenna groups, e.g., as described herein with respect to Figure 8As described, and if at least one of the backoff factors of the first grouping is less than a second threshold (e.g., 0.5), the transmit antennas are assigned to a second grouping of antenna groups. In some cases, the first grouping may include a separate antenna group for each transmit antenna, and the second grouping may include at least one antenna group having multiple transmit antennas. That is, a first iteration of the antenna grouping procedure may involve determining a backoff factor for each antenna and determining which transmit antennas to group together based on these backoff factors, and subsequent iterations may, for example, refine or adjust the assignment of antennas to specific antenna groups based on the determined backoff factors.

[0129] The processing system may repeatedly determine the backoff factors and assign the transmit antennas to the antenna groups until all backoff factors are greater than the second threshold. For example, the processing system may determine the backoff factors for the second grouping of antenna groups (e.g., repeating the backoff factors described herein with respect to Figure 8 The method further comprises: performing the operations described in the embodiment of the present invention, and if at least one of the backoff factors of the second group is less than the threshold value, assigning the transmit antenna to a third group of antenna groups. In some cases, the third group may include at least two antenna groups, each of which has multiple transmit antennas. That is, the assignment of the third group may further refine the antenna groups to include multiple antennas in more than two antenna groups.

[0130] In some aspects, the antenna groups may include mixed-mode antennas (e.g., sub-6 GHz and millimeter wave antennas). For example, at least one of the antenna groups may include a first antenna configured to transmit in a first mode and a second antenna configured to transmit in a second mode. The first mode may be a sub-6 GHz frequency band transmission mode, and the second mode may be a millimeter wave frequency band transmission mode. In other words, the first mode may be transmitting at one or more frequencies at or below 6 GHz (e.g., 300 MHz to 6 GHz), and the second mode may be transmitting at one or more frequencies above 6 GHz (e.g., 24 GHz to 53 GHz or higher). That is, the first mode may include a first antenna operable at one or more frequencies at or below 6 GHz, and the second mode may include a second antenna operable at one or more frequencies above 6 GHz.

[0131] In various aspects, a transmit antenna configuration may include a transmit beam configuration for a particular antenna or an antenna module having multiple antennas. In various aspects, at least one of the transmit antennas is part of an antenna module having multiple antennas. For example, at block 602, an RF exposure distribution may be generated (and / or an indication thereof may be received) for each of the multiple antennas and / or for each transmit beam configuration supported by an antenna module among the multiple antennas. In various aspects, a transmit beam configuration may refer to a transmit radiation pattern from an antenna or antenna module in a particular azimuth direction and / or elevation direction, which may be achieved through beamforming. The transmit beam configuration may have a certain transmit power spread (e.g., a power angle spread associated with a departure angle) in the azimuth direction and / or elevation direction.

[0132] In some cases, antenna grouping may be used to determine RF exposure compliance and corresponding transmit power levels. For example, the UE may transmit a signal at a transmit power level based on enforcing RF exposure compliance for at least one of the antenna groups. In some aspects, enforcing RF exposure compliance may include the UE meeting certain RF exposure limits (e.g., a SAR limit of 1.6 Watts / kilogram (1.6 W / kg) and / or a SAR limit of 1.0 milliwatts / square centimeter (1.0 mW / cm 2 )’s PD limit).

[0133] In various aspects, ensuring RF exposure compliance may include evaluating RF exposure compliance according to time-averaged RF exposure (such as time-averaged SAR or time-averaged PD within a time window). In various aspects, the time window may be in the range of 1 second to 360 seconds. For example, the time window may be 100 seconds or 360 seconds. The range of 1 second to 360 seconds is an example, and other suitable values ​​of the time window may be used. In some cases, the time window may be less than 1 second, such as 500 milliseconds. In some cases, the time window may be greater than 360 seconds, such as 600 seconds.

[0134] In various aspects, the UE may communicate with a base station, such as BS 110. For example, at block 608, the UE may send user data to the base station on a physical uplink shared channel (PUSCH) or send various uplink feedback (e.g., uplink control information or hybrid automatic repeat request (HARQ) feedback) to the base station on a physical uplink control channel (PUCCH). In some cases, the UE may communicate with another UE. For example, at block 608, the UE may send user data and / or various feedback to the other UE on a sidelink channel.

[0135] Figure 7is a block diagram illustrating an example grouping of multiple antennas of a wireless communication device 700 according to certain aspects of the present disclosure. In this example, the wireless communication device 700 (e.g., UE 120, such as a smartphone, or any wireless communication device described herein) includes a first antenna 702a, a second antenna 702b, a third antenna 702c, a fourth antenna 702d, a fifth antenna 702e, a sixth antenna 702f, and a seventh antenna 702g. In this example, the antennas 702a-702g are divided into three antenna groups 704, 706, 708, which roughly correspond to the top of the device 700, the bottom of the device 700, and the side of the device 700 when the device 700 is held in an upright position. Those skilled in the art will appreciate that more or less than seven antennas may be implemented, and / or more or less than three antenna groups may be defined. Each of the illustrated antennas 702a-702g may represent a single antenna, an antenna array (e.g., a phased array), or a module including one or more antennas. Antenna groups 704, 706, 708 may each include one or more antennas configured to transmit in a certain frequency band (e.g., very high (e.g., millimeter wave band), high (e.g., 6 GHz to 7 GHz band), medium (e.g., 3 GHz to 6 GHz band), or low (e.g., 400 MHz to 3 GHz band)), or the antenna groups may each include one or more antennas configured to transmit in multiple frequency bands.

[0136] In various aspects, the antenna groupings described herein may be assigned to various antenna groupings, such as millimeter wave groupings, sub-6 GHz groupings, low-band groupings (e.g., 400 MHz to 3 GHz bands), mixed-mode groupings (e.g., millimeter wave and sub-6 GHz groupings), for example, for different transmission scenarios. For example, under millimeter wave groupings, each millimeter wave module (e.g., the first antenna 702a, the third antenna 702c, and the fifth antenna 702e) may be considered as a separate antenna group, where each millimeter wave module may have multiple antenna elements (e.g., 64 dual-polarized antenna elements) arranged in one or more arrays. The millimeter wave modules may be able to transmit various beams via predefined antenna configurations, where the beams may form a codebook. Under sub-6 GHz groupings, the sub-6 GHz antennas may be grouped into separate groups. For example, the second antenna 702b and the fourth antenna 702d may be assigned to one group, and the sixth antenna 702f and the seventh antenna 702g may be assigned to another group. In some cases, antennas 702a-702g may be assigned to mixed-mode groupings, such as three antenna groups 704, 706, 708.

[0137] The groups may be defined and / or operated so as to be mutually exclusive in terms of RF exposure. In certain aspects, the transmit power of one or more of the groups (or one or more of the antennas within one or more groups) may be reduced so that the (normalized) sum of the exposure or overlapping RF exposure distributions of all antenna groups is less than a certain value (e.g., 1.0). For example, a backoff factor may be determined for one or more groups or one or more antennas within one or more groups, and the backoff factor may be applied so as to limit the transmit power of the antennas and / or groups.

[0138] For example, for each antenna group, the backoff factor bf may be between [0, 1], such that the maximum permitted transmit power of each antenna group is equal to the corresponding backoff factor multiplied by the transmit power limit of the antenna group (e.g., bf*Tx_power_limit), where bf=1 indicates no backoff, where bf=0.3 indicates operating the antenna group at 30% of the transmit power limit, and where the transmit power limit may be the maximum transmit power supported by the particular antenna and / or antenna group.

[0139] Figure 8 8 is a flow diagram illustrating example operations 800 for determining a backoff factor for an antenna group in accordance with certain aspects of the present disclosure. Operations 800 may be performed, for example, by a UE (e.g., UE 120a in wireless communication network 100), an RF exposure measurement system (e.g., RF exposure measurement system 500), and / or a processing system. To determine such backoff factors, at block 802, an RF exposure distribution (simulated and / or measured) may be generated for each transmit antenna / configuration (beam) (as described above) on all evaluation surfaces / positions at all locations, for example, using a processing system and / or RF exposure measurement system 500. In certain aspects, the RF exposure distribution may be generated via simulations, such as simulations of various exposure / transmission scenarios using a human body model exposed to electromagnetic radiation from a wireless communication device. As previously described herein, the RF exposure distribution may include RF exposures associated with various transmission scenarios corresponding to specific frequency bands and / or positions of a human body relative to an antenna. For example, the RF exposure distribution may be represented by the following expression: RFexp(s,x,y,z,i), where s represents a specific surface or location, (x,y,z) represents a given location, and i represents a specific transmit configuration, such as a specific antenna or transmit beam. In some cases, a transmit antenna may support multiple frequency bands, so multiple RF exposure distributions for each frequency band / channel (low / medium / high) may be available for a specific transmit antenna. In this case, the RF exposure distribution for a specific transmit antenna may represent the maximum exposure among all technologies / frequency bands / channels supported by the transmit antenna at each location / exposure surface.

[0140] Then, at block 804, a normalized distribution (map) may be calculated by collecting the exposures on all surfaces / positions of each transmit antenna / beam and dividing by the corresponding maximum value. For example, the normalized distribution may be represented by the following expression: normalized.map(s,x,y,z,i) = {RFexp(1,x,y,z,i); RFexp(2,x,y,z,i); ...; RFexp(s,x,y,z,i)} / maxRFexp(i).

[0141] Thereafter, at block 806, a normalized composite map for each antenna group may be calculated, for example, based on the maximum value of the normalized distributions in the group. That is, generating the normalized composite map may include selecting the maximum normalized distribution among the normalized distributions in the particular antenna group. For example, the normalized composite map may be given by the following expression: normalized.composite.map.AG k (s,x,y,z)=max{normalized.map(s,x,y,z,i), 1 to n antennas / beams within}, where AG k Indicates a specific antenna group (AG).

[0142] In addition, at block 808, a total normalized composite mapping for all antenna groups may be calculated, for example, based on the sum of all normalized composite mappings. For example, the total normalized composite mapping may be given by the following expression:

[0143] Total.normalized.composite.map(s,x,y,z)=

[0144]

[0145] where bf k Indicates the backoff factor for a specific antenna group.

[0146] In certain aspects, at block 810, it may be determined whether the total normalized composite map is less than a threshold value (e.g., 1.0). If the condition is not met, the expected or potential power of one or more antennas (or one or more antenna groups) may be reduced using an updated backoff factor. For example, the contribution of the antenna groups to the RF exposure may be at different levels due to the location of the antennas within the group, the supported frequency bands of the antennas within the group, the maximum transmit power of the antennas within the group, etc. The contribution of the antenna groups to the RF exposure (e.g., based on the total normalized composite map, where the overlapped map is at a peak, etc.) may be adjusted using the backoff factor of the antenna group. At block 812, for example, the backoff factor may be adjusted (increased or decreased) for one or more of the antenna groups, and the total normalized composite map may be recalculated using the updated backoff factor at block 808. The backoff factor for each antenna and / or group may be adjusted (or updated), and the total normalized composite map may be recalculated using the adjusted backoff factor until the condition at block 810 is met (e.g., the total normalized composite map is less than or equal to the threshold value). In some examples, the backoff factor for each transmitter (or antenna, or group of antennas or transmitters) can be determined based on the proportion of RF exposure attributable to each transmitter at one (e.g., peak) location and the desired reduction in exposure. In some examples, the backoff factor can be determined based on the priority of the transmitters coupled to the antenna. In some examples, the backoff factor of the antenna that contributes most to the RF exposure at (e.g., peak) is the maximum backoff factor compared to the backoff factors of the other antennas or groups. In some examples, the backoff factor is determined so that the transmit power level of each of several antennas or groups contributes approximately equally to the RF exposure at one location. The backoff factor can be determined or applied uniformly to the antennas within a group, or can vary across the antennas in the group.

[0147] At block 814, if the total normalized composite map is less than a threshold (e.g., 1.0), the antenna groups are considered mutually exclusive in terms of RF exposure, and a final backoff factor for each antenna group may be obtained at block 816. The backoff factor may be used to determine a transmit power level for a particular antenna group, as further described herein, or for other purposes, such as determining actual or potential interference.

[0148] Fig. 9 8 is a flow diagram illustrating example operations 900 for assigning antennas to groups based on backoff factors (e.g., as determined in operations 800), in accordance with certain aspects of the present disclosure. Operations 900 may be performed, for example, by a processing system including a UE (e.g., UE 120a in wireless communication network 100) and / or an RF exposure measurement system (e.g., RF exposure measurement system 500).

[0149] At block 902, a backoff factor for each antenna group may be obtained, for example, after completing operation 800 for grouping certain antennas. For example, at block 902, operation 800 may first be performed using a separate group for each of the antennas / beams to obtain a backoff factor for the separate antennas.

[0150] At block 904, it may be determined whether each of the backoff factors is greater than or equal to a threshold value (e.g., 0.5). If the condition is not met, then at block 906, the antennas may be reassigned or reallocated among the antenna groups. In some cases, for antennas / antenna groups with low backoff factors (e.g., backoff factors < 0.5), some antennas may be grouped together into the same antenna group based on spatial distribution, resulting in a reduction in the number of antenna groups. For example, assume that in the first iteration, a separate group is used for each antenna, where antennas 1 to 7 are in antenna groups AG1 to AG7, respectively. The corresponding backoff factors are: bf1 = bf2≈0.5, bf3≈1, bf4=bf5=bf6=bf7≈0.25. Then, the updated antenna groups may be AG1={Ant4, Ant5, Ant6, Ant7}, AG2={Ant1, Ant2}, and AG3={Ant3}. In some cases, at block 904, particular antennas may be grouped together such that the sum of the backoff factors for the particular antennas is above a threshold. At block 902, operations 800 or a portion of operations 800 (e.g., blocks 806-816) may be repeated to determine updated backoff factors for the reassigned antenna group. Antenna grouping / backoff factor generation may be repeated until all backoff factors meet the conditions at blocks 810 and 904. If the conditions at these blocks are met, the antenna group assignment may be considered complete.

[0151] The antenna grouping operations described herein may be determined and / or applied according to a device state index (DSI) and / or an exposure category indicating an exposure scenario of the device (e.g., head exposure, body exposure, or limb exposure). For example, head exposure may have four exposure positions (right cheek, right tilt, left cheek, and left tilt), and these four positions may be collected together (e.g., at box 804, collected into a normalized map; in some cases, the value of s will be in the range of [1, 4] to consider four exposure positions, where s represents a specific surface or position). Body exposure may have two exposure positions (front surface and back surface), and these two exposure positions may be collected together (e.g., at box 804). Limb exposure may have six exposure positions (front surface, back surface, left surface, right surface, top surface, and bottom surface of the device) separated by a distance of 0 mm, and these six positions may be collected together (e.g., at box 804).

[0152] In certain aspects, the antenna grouping operations described herein may be combined with existing methods for some exposure configurations, e.g., if the absolute sum of the maximum RF exposure values ​​for all antenna groups (e.g., the total normalized composite map) is less than the regulatory limit, then the above-described procedure for adjusting the power / backoff factors may be skipped.

[0153] Although the examples provided herein are described with respect to the UE performing various operations when determining antenna grouping, aspects of the present disclosure may also be applied to scenarios in which antenna grouping and backoff factor derivation operations are performed in a laboratory environment (such as with the RF exposure measurement system 500) and certain calculations or simulations are performed, for example, by a separate processing system (such as the processing system 502) outside the UE. That is, the various functions for antenna grouping and backoff factor derivation operations do not need to be completed at the UE itself, but rather the UE may be configured to store / access / utilize specific information derived from the antenna grouping operations, such as backoff factors and antenna grouping assignments. For example, a (prototype of) wireless communication device may be used in a laboratory environment (e.g., the RF exposure measurement system 500) to establish antenna grouping assignments and corresponding backoff factors in order to simulate various exposure / transmission scenarios during the RF exposure compliance certification process with a regulatory agency, and the UE may be configured to store / access / utilize backoff factors associated with specific antenna groupings derived from the antenna grouping operations performed in the laboratory environment.

[0154] For example, the UE may store and access various backoff factors associated with specific antenna groups and / or transmit beam configurations based on various RF exposure limits associated with exposure / transmission scenarios (such as head exposure, body exposure, and / or limb exposure at certain frequency bands). The backoff factors associated with specific antenna groups and / or transmit beam configurations may be established based on operations for assigning antenna groups as described herein (e.g., using a prototype of the UE in an RF exposure test lab). The backoff factors associated with specific antenna groups may be arranged in a data structure, such as a table or database of backoff factors associated with specific antenna groupings and / or specific exposure / transmission scenarios at specific frequency bands.

[0155] Although the examples provided herein are described with respect to UE performing RF exposure compliance with antenna grouping, aspects of the present disclosure are not limited to RF exposure use cases. For example, stored values ​​derived from antenna grouping operations (e.g., backoff factors and / or antenna grouping assignments) can be used for any number of applications. One application, as further described below, is to use backoff factors and / or antenna grouping to evaluate RF exposure compliance. Another application may be to determine self-interference between antenna groupings based on transmit power levels. Other purposes are also possible.

[0156] In some cases, an antenna may not meet the exclusion criteria of another antenna group, and in such cases, the antenna may be incorporated into another antenna group. In some cases, this may result in all antennas being combined into a single antenna group, which means that the RF exposure from all antennas is collocated and the spatial diversity caused by the antenna arrangement is not utilized. One way to avoid this is to force one or more antennas to meet the exclusion criteria by applying a higher permanent backoff to the antenna.

[0157] Various aspects of the present disclosure relate to assigning antennas to multiple antenna groups within a particular antenna grouping. For example, if an antenna does not meet the exclusion criteria of another antenna group, the antenna can be assigned to multiple antenna groups, which can avoid applying permanent backoffs to all antennas. The antenna groupings described herein can enable desired transmit power for a particular antenna group and / or flexibility in complying with RF exposure limits for each antenna group.

[0158] Various aspects of the present disclosure relate to assigning one or more antennas to multiple sets of antenna groups (i.e., multiple antenna groups), for example, for separate transmission scenarios. For example, a processing system may establish antenna groups for a specific country or region (e.g., which may be identified by a public land mobile network (PLMN) code and / or a mobile country code (MCC)) because the country or region has separate RF exposure limits. In some cases, the processing system may establish antenna groups for specific exposure scenarios (such as head exposure, body exposure, limb exposure, and / or hot spot exposure (e.g., when the wireless communication device is not in close proximity to human tissue)) and / or based on one or more operating conditions (whether MIMO is being utilized, for certain frequency bands, when certain high priority applications or transmissions may be active, etc.). Antenna groups for each transmission scenario (such as a specific region and / or exposure scenario) may provide flexibility for the wireless communication device to switch between antenna groups according to the transmission scenario encountered by the wireless communication device.

[0159] Return to Figure 6 , the operations 600 may also involve a processing system (e.g., a UE, an RF exposure measurement system, a computer separate from the UE, and / or any other device configured to perform the operations described herein) assigning at least one of the transmit antennas to two or more of the antenna groups at block 604. For example, the processing system may assign the antenna to multiple antenna groups because the antenna does not meet the exclusion criteria of the other antenna groups. At block 604, the processing system may identify that at least one of the transmit antennas does not meet the mutual exclusion criteria of at least two of the antenna groups, and the processing system may assign at least one of the transmit antennas to at least two of the antenna groups in response to the identification.

[0160] In some cases, the maximum time-averaged power limit (Plimit ) to assign the antenna to multiple antenna groups. The maximum time-averaged power limit may refer to the maximum constant transmit power that the antenna can continuously transmit in compliance with the RF exposure limit during the entire duration of the time window associated with the RF exposure limit. For example, if an antenna has a relatively low P value compared to other antennas, limit , the processing system may not repeatedly assign the particular antenna in multiple antenna groups to avoid consuming the RF exposure margin in those antenna groups. For example, if a particular antenna has a relatively high P limit , the processing system can assign the specific antenna to multiple antenna groups. limit The maximum transmit power (P max ) to quantify the low or high P for a particular antenna (and a particular technology / band). limit In such scenarios, the peak-to-average power ratio (PAPR) can be used to determine P limit A measure of whether the PAPR is relatively low or relatively high. The PAPR in dB can be expressed by P max -P limit Given, where P max and P limit It can be expressed in dBm. For example, if the PAPR is positive (say, a few dB, such as 2dB, 3dB, or 6dB), then for that particular technology / band / antenna, P limit Similarly, if the PAPR is less than one of these example values ​​or is negative, then P limit With respect to operation 600, the processing system may identify a maximum time-averaged power limit associated with each of the transmit antennas, and the processing system may assign at least one of the transmit antennas to at least two of the antenna groups based at least in part on the maximum time-averaged power limit associated with at least one of the transmit antennas.

[0161] In certain aspects, the processing system may generate multiple antenna groups. Antenna groups may be established for separate transmission scenarios, such as when the wireless communication device is located in a specific region and / or when the wireless communication device encounters a specific exposure scenario. With respect to operation 600, the processing system may assign transmit antennas to a first group of antenna groups for a first transmission scenario (e.g., when the UE is located in the United States), and assign transmit antennas to a second group of antenna groups for a second transmission scenario (e.g., when the UE is located in the European Union).

[0162] In some aspects, the first group may have a different arrangement of transmit antennas in the plurality of antenna groups than the second group. At least one of the transmit antennas is in both the first group and the second group. For example, referring to Figure 7, antennas 702a-702g may be assigned to a first grouping, wherein the first antenna 702a, the second antenna 702b, the third antenna 702c, the fourth antenna 702d, and the fifth antenna 702e are assigned to the first group; and the fifth antenna 702e, the sixth antenna 702f, and the seventh antenna 702g are assigned to the second group. The first group may be spatially separated from the second group to provide a mutually exclusive relationship in terms of RF exposure. In this first grouping, the fifth antenna 702e is assigned to two different antenna groups (i.e., the first group and the second group). Since the fifth antenna 702e is positioned between the sets of top and bottom antennas (702a-702d, 702f, and 702g), the fifth antenna 702e may be difficult to separate into mutually exclusive exposure groups. For example, the fifth antenna 702e may interact with other antennas (702a-702d, 702f, and 702g), and in order to avoid applying restrictive permanent backoff, the fifth antenna 702e may be assigned to the first group and the second group.

[0163] The antennas 702a-702g may also be assigned to a second grouping, where the first antenna 702a, the second antenna 702b, the third antenna 702c, and the fourth antenna 702d are assigned to the third group; the sixth antenna 702f and the seventh antenna 702g are assigned to the fourth group; and the fourth antenna 702d, the fifth antenna 702e, and the seventh antenna 702g are assigned to the fifth group. In this second grouping, the fourth antenna 702d is assigned to two different antenna groups (i.e., the third group and the fifth group), and the sixth antenna 702g is assigned to two different antenna groups (i.e., the fourth group and the fifth group). In this second grouping, the fifth antenna 702e may also be difficult to assign to a separate group, and the fifth antenna 702e may be grouped together with antennas spatially arranged on the same side of the wireless communication device 700, such as the fourth antenna 702d and the seventh antenna 702g.

[0164] In some cases, the first transmission scenario may be associated with a first country or region (e.g., the United States), and the second transmission scenario may be associated with a second country or region (e.g., China or the European Union). That is, the first transmission scenario and the second transmission scenario may depend on a specific region where the UE is located to comply with specific RF exposure limits in the region. When the UE is located in the specific region (e.g., as determined based on a PLMN code and / or MCC provided to the UE), the UE may use a certain antenna grouping associated with the region.

[0165] In some cases, the first transmission scenario may be associated with a first exposure scenario (e.g., head exposure), and the second transmission scenario may be associated with a second exposure scenario (e.g., body exposure). That is, the first transmission scenario and the second transmission scenario may depend on a specific exposure scenario, such as head exposure, body exposure, limb exposure, and / or hot spot exposure. When the UE encounters a specific exposure scenario, the UE may use a certain antenna grouping associated with the exposure scenario.

[0166] In some cases, a transmission scenario may be associated with when certain antennas are used for concurrent transmission. For example, assume that the fourth antenna 702d and the seventh antenna 702g are to be used together for concurrent transmission. The processing system may assign these antennas to different groups to facilitate efficient use of the RF exposure margins for these antennas. For example, when the fourth antenna 702d and the seventh antenna 702g are used for concurrent transmission to enable separate backoffs to be applied to these antennas, the processing system may, as described herein with respect to Figure 7 The first group is created as described.

[0167] With respect to operation 600, the UE may transmit from at least one transmit antenna in the first group during a first transmission scenario, and the UE may transmit from at least one transmit antenna in the second group during a second transmission scenario. In other words, the UE may select which antenna group to use for a particular transmission scenario, and when there is a change in the transmission scenario, such as when the UE moves from one region to another, the UE may switch between antenna groups, for example, as described herein with respect to Fig.10 Further described.

[0168] Example time-averaged RF exposure per transmit antenna group

[0169] Various aspects of the present disclosure provide various techniques for determining the time-averaged RF exposure compliance of each transmit antenna group. Since the antenna grouping described herein can provide antenna groups that are mutually exclusive in terms of RF exposure, the RF exposure compliance of each antenna group can be determined separately. In some cases, the RF exposure compliance of the antenna groups can be performed in parallel (e.g., performed together concurrently). The group-based RF exposure compliance described herein can achieve the desired transmit power for a particular antenna group, for example, due to the different exposure scenarios encountered by each antenna group. The desired transmit power can provide desired uplink performance, such as desired uplink data rate, uplink carrier aggregation, and / or uplink connectivity at the cell edge.

[0170] Fig.10 1 is a flow diagram illustrating example operations 1000 for wireless communications in accordance with certain aspects of the present disclosure. Operations 1000 may be performed, for example, by a UE (e.g., UE 120a in wireless communication network 100). Operations 1000 may be implemented as a processor on one or more processors (e.g., Figure 2 In addition, the signal transmission performed by the UE in operation 1000 may be performed by one or more antennas (e.g., Figure 2 In some aspects, the transmission and / or reception of signals by the UE may be implemented via a bus interface of one or more processors (eg, controller / processor 280) that obtains and / or outputs signals.

[0171] Operations 1000 may begin at block 1002, where a UE may access a stored backoff factor associated with an antenna group (e.g., antenna group 704) among a plurality of antenna groups (e.g., antenna groups 704, 706, 708). At block 1004, the UE may transmit a signal from at least one transmit antenna in the antenna group (e.g., antenna 702a) at a transmit power level based on the backoff factor that complies with RF exposure limits.

[0172] In some cases, the grouping of transmit antennas may not be an explicit indication of which antennas are in a particular group. In various aspects, the grouping of transmit antennas may be implicitly indicated by various backoff factors assigned to transmit antennas for particular exposure / transmission scenarios. That is, antenna groupings and antenna group assignments associated with antenna groupings may be represented by backoff factors. For example, certain antennas may share the same backoff factor such that these antennas are implicitly assigned to the same antenna group among a plurality of antenna groups. In various aspects, the transmit power level may be based at least in part on at least one of the backoff factors.

[0173] In certain aspects, the transmit power level may be determined based on the sum of the RF exposure being less than or equal to a threshold value (e.g., 1.0). For example, the UE may transmit a signal at a transmit power level based on the sum of the RF exposure of each antenna group in the antenna group being less than or equal to the threshold value. In some such scenarios, this is achieved by applying the backoff factor described above to the transmit power level.

[0174] In certain aspects, the transmit power level may be determined based on the time average RF exposure being less than a threshold. For example, the UE may transmit a signal at a transmit power level based on the time average sum of the RF exposure of each antenna group in the antenna group being less than or equal to a threshold (e.g., 1.0). In the case of the sum of the RF exposure or the time average sum of the RF exposure, a backoff factor may be applied to the RF exposure of each antenna group in the antenna group.

[0175] In various aspects, the UE may determine the time-averaged RF exposure of each antenna group in the antenna group, and use the group-based time-averaged RF exposure when determining RF exposure compliance. For example, the UE may transmit a signal at a transmit power level based on each of the time-averaged RF exposures being less than or equal to a threshold. In some cases, because the antenna groups may be mutually exclusive of each other in terms of RF exposure, the UE may concurrently determine the time-averaged RF exposure of each antenna group in the antenna group. In other words, the mutual exclusivity of the antenna groups may enable the UE to determine the time-averaged RF exposure of each antenna group in the antenna group in parallel (e.g., independently) with each other. Expressed in another way, the UE may use parallel (or concurrent) processing to determine the time-averaged RF exposure of each antenna group or a portion of the antenna group. For example, the UE may determine the time-averaged RF exposure associated with the first antenna group (e.g., antenna group 704) while concurrently determining the time-averaged RF exposure associated with the second antenna group (e.g., antenna group 706), and the UE may determine the transmit power that complies with the RF exposure limit of each of the first antenna group and the second antenna group based on the corresponding time-averaged RF exposure and the corresponding backoff factor. In some cases, the UE may transmit a signal at a transmit power level based on enforcing RF exposure compliance for one of the plurality of antenna groups having a smaller transmit power limit than another of the plurality of antenna groups. That is, a minimum of the plurality of transmit power limits may be enforced by the transmitter to ensure total time average RF exposure compliance.

[0176] In various aspects, the antennas may have various antenna groupings, for example, as described herein with respect to operation 600. For example, the UE may have backoff factors associated with antenna groups for millimeter wave bands, antenna groups for sub-6 GHz bands, and / or antenna groups for mixed-mode bands (sub-6 GHz bands and millimeter wave bands). In some cases, antenna groupings may be derived using operations 600, 800, or 900. For example, at least one of the antenna groups may include a first antenna configured to transmit in a first mode and a second antenna configured to transmit in a second mode. In some cases, the first mode may be sub-6 GHz, and the second mode may be millimeter wave. That is, the first mode may be transmitted at a sub-6 GHz band, and the second mode may be transmitted at a millimeter wave band. In various aspects, the first mode may include a first antenna operable at a sub-6 GHz band, and the second mode may include a second antenna operable at a millimeter wave band.

[0177] In some aspects, the transmitting antenna may include one or more first antennas configured to transmit in a first mode and one or more second antennas configured to transmit in a second mode. The first antennas may be individually assigned to antenna groups. That is, the first antennas may be divided into groups so that some of the first antennas may be in the same group, but one of the first antennas may not be assigned to more than one group in a specific antenna grouping. The second antenna may be included in each or some of the antenna groups in the antenna group. In some cases, each antenna group in the antenna group may have all second antennas. In some cases, the first mode may be transmitted at one or more frequencies below 6 GHz (e.g., at a frequency band below 6 GHz), and the second mode may be transmitted at one or more frequencies above 6 GHz (e.g., at a millimeter wave band). In other cases, the first mode may be transmitted at one or more frequencies above 6 GHz, and the second mode may be transmitted at one or more frequencies below 6 GHz.

[0178] In various aspects, the transmit antennas are grouped such that each antenna group is mutually exclusive with respect to RF exposure from all other antenna groups. The mutual exclusivity of the antenna groups may be achieved using various techniques or criteria. For example, in a system of N antennas grouped into k antenna groups, a normalized RF exposure distribution = normalized.map(s, x, y, z, i) is first obtained for each antenna from i = 1 to N antennas over all exposure surfaces of interest, as represented in block 804, such that the maximum value of the RF exposure distribution outside all surfaces is max{normalized.map(s, x, y, z)} = 1.0. A composite map = normalized.composite.map.AG is then obtained from all n antennas within antenna group k k (s,x,y,z)=max{normalized.map(s,x,y,z,i=1 to n)}, as represented in block 806, =normRFexposure(k,s,x,y,z) 。 This normalized composite mapping is called the normalized RF exposure of antenna group k. For example, if the sum of the RF exposures of all antenna groups (k=1 to M) < 1.0 satisfies the following expression, the mutual exclusivity of the antenna groups can be provided:

[0179]

[0180] Wherein the predefined backoff (k) is a backoff factor applied to all antennas and / or antenna configurations of antenna group "k". The backoff factor may be determined based on operations 600, 800 and / or 900, and / or the backoff factor may be stored by the UE (e.g., in memory 282 or 338) and retrieved for use when performing operation 1000. In some cases, existing regulatory methods that meet predefined criteria (such as SAR peak position separation ratio (SPLSR)) may be used to determine such mutual exclusivity (e.g., as described in Section 4.3.2c of FCC KDB447498D01 General RF Exposure Guidance v06). In some cases, the mutual exclusivity of the antenna group may be determined by the sum of overlapping RF exposure distributions at a specific backoff factor that is less than or equal to a threshold value (e.g., 1.0). The predefined backoff factor is between [0,1] and is applied to all antennas belonging to the antenna group. This may be achieved by reducing the maximum time-averaged transmit power limit of each antenna belonging to antenna group k by the predefined backoff (k). Alternatively, the total RF exposure of all antennas at all spatial locations (s, x, y, z) in antenna group k should not exceed RFexposure limit * Predefined backoff (k).

[0181] Since antenna groups are mutually exclusive in terms of RF exposure, a (real-time) averaging of RF exposure may be performed for each antenna group (e.g., without considering other antenna groups) using the above method or using one or more other methods. For example, the RF exposure of a given antenna at any time t may be proportional to the transmit power of the antenna at time t. Thus, the RF exposure of antenna i belonging to antenna group k at time t may be given by:

[0182]

[0183] The time-averaged RF exposure of all n antennas and / or antenna configurations in antenna group k within a time window T can be given by:

[0184]

[0185] The predefined backoff may be the backoff factor bf described herein.

[0186] When antennas and / or antenna groups that use different mechanisms (eg, SAR or PD) to calculate RF exposure are included in an antenna group, the exposures may be combined as described herein or using one or more other methods or calculations.

[0187] Thus, transmission (power) using antennas in an antenna group may be controlled (e.g., by processor 280) such that each group individually meets exposure limits defined, for example, by a regulatory body in a domestic or foreign jurisdiction. In some aspects, this may result in a higher total power transmitted across all antenna groups than would be the case if the antennas were not divided into mutually exclusive exposure groups.

[0188] In some cases, multiple sets of antenna groups (e.g., multiple antenna groups) may be defined and used to determine (e.g., transmit power and / or backoff factor) settings for multiple transmitters and / or antennas. That is, a UE may be configured with multiple antenna groups, where each antenna group has antenna groups that may be defined differently from other antenna groups. For example, referring to Figure 7 , the first antenna 702a, the third antenna 702c, and the fifth antenna 702e may be antenna modules having antenna arrays configured to transmit in one or more millimeter wave frequency bands (e.g., about 24 GHz to 53 GHz or higher). The other antennas 702b, 702d, 702f, 702g may be configured to transmit in sub-6 GHz frequency bands (e.g., 6 GHz or lower).

[0189] The first antenna grouping (M1) may include three antenna groups, and the second antenna grouping (M2) may include two antenna groups. The antenna groups of the first antenna grouping (M1) may include a first antenna group (AG1) having all sub-6 GHz antennas 702b, 702d, 702f, 702g and a first antenna 702a, a second antenna group (AG2) having all sub-6 GHz antennas 702b, 702d, 702f, 702g and a third antenna 702c, and a third antenna group (AG3) having all sub-6 GHz antennas 702b, 702d, 702f, 702g and a fifth antenna 702e. In various aspects, the first antenna grouping (M1) may be represented as follows:

[0190] AG1: {All sub-6GHz antennas, first millimeter wave module}

[0191] AG2: {all sub-6GHz antennas, second millimeter wave module}

[0192] AG3: {all antennas below 6GHz, third millimeter wave module}

[0193] The antenna group of the second antenna group (M2) may include a fourth antenna group (AG4) having a second antenna 702b, a fourth antenna 702d, and all millimeter wave antennas 702a, 702c, and 702e, and a fifth antenna group (AG5) having a sixth antenna 702f, a seventh antenna 702g, and all millimeter wave antennas 702a, 702c, and 702e. The second antenna group may be represented as follows:

[0194] AG4: {First subgroup of antennas below 6GHz, all mmWave modules}

[0195] AG5: {Second subgroup of antennas below 6GHz, all mmWave modules}

[0196] The first subgroup may include antennas below 6 GHz (such as the second antenna 702b and the fourth antenna 702d) arranged at the top of the UE, and the second subgroup below 6 GHz may include antennas below 6 GHz (such as the sixth antenna 702f and the seventh antenna 702g) arranged at the bottom of the UE.

[0197] In some aspects, sub-6 GHz (e.g., frequency range 1 (FR1)) RF exposure may be calculated via measurement, and mmWave (e.g., frequency range 2 (FR2)) RF exposure (for beams in a codebook) may be calculated via simulation (e.g., as described above). In such cases, sub-6 GHz antennas may be grouped into M2 groups (with all mmWave modules in each of the groups), and mmWave antennas may be grouped into M1 groups (with all sub-6 GHz antennas in each of the groups), as described above.

[0198] Those skilled in the art will appreciate that groups M1 and M2 are merely examples for arranging antennas into groups for ease of understanding. Aspects of the present disclosure may also be applied to arranging antennas into additional or alternative groups, such as the groupings described above with respect to assigning antennas to multiple groups. For example, any one of all FR1 or FR2 radios may be assigned to all antenna groups, and the other of the FR1 or FR2 radios may be non-uniquely distributed between antenna groups. In one such example, antenna grouping (M3) may include a fourth antenna group AG4 and a fifth antenna group AG5, plus an additional antenna group (AG6) having a second antenna 702b, a sixth antenna 702f, and all millimeter wave antennas 702a, 702c, and 702e. In another such example, antenna grouping (M4) may include a fourth antenna group AG4 and a seventh antenna group (AG7) having a second antenna 702b, a sixth antenna 702f, a seventh antenna 702g, and all millimeter wave antennas 702a, 702c, and 702e.

[0199] In these examples, two or more determinations of time averaging may be performed (e.g., at least one determination of time averaging may be performed for a set, for example, based on one or more backoff values ​​defined for each set). Processor 280 may determine to apply transmit settings to the antenna based on the results of the two or more determinations. In some aspects, a minimum of transmit power limits grouped across multiple antennas (e.g., M1 versus M2, or M1 versus M3 and / or M4) may be selected and implemented by processor 280, for example, to ensure overall time-averaged RF exposure compliance.

[0200] In some cases, the UE may access the stored backoff factor and transmit a signal from at least one antenna using a transmit power level based on the backoff factor that complies with the RF exposure limit, as described herein. The backoff factor may correspond to at least one antenna group in the plurality of antenna groups, wherein the at least one antenna is in the at least one antenna group.

[0201] Example selection and switching between sets of antenna groups

[0202] Various aspects of the present disclosure relate to selecting a set of antenna groups (also referred to herein as "groups") for operation by a wireless communication device (e.g., UE 120). Operating using a specific set of antenna groups may be beneficial for certain radio transmission scenarios (e.g., by providing higher performance). For example, when operating using antenna groups (AG1, AG2, and AG3) of a first antenna grouping (M1), the mmW module may obtain more combined total RF exposure margins because each mmW module may obtain up to 100% RF exposure margin in this scenario (depending on how much margin is consumed by the sub-6 GHz antenna). Therefore, when operating using LTE and frequency range 2 (FR2) in NR (e.g., LTE+FR2 link), it may be beneficial to operate according to the M1 grouping. In contrast, when operating using only sub-6 GHz bands (e.g., LTE and frequency range 1 (FR1) in NR, such as in an LTE+FR1 link), it may be beneficial to operate according to, for example, the M2 grouping (utilizing AG4 and AG5) or one of the M3 and M4 groups.

[0203] Various aspects of the present disclosure also relate to switching between sets of antenna groups, such as when a wireless communication device (e.g., UE 120) changes its operating parameters. When switching from one antenna grouping to another (e.g., for performance benefits), RF exposure compliance should preferably be ensured because the grouping assumptions may have changed. For example, when switching from an M1 grouping to an M2 grouping (or from an M1 grouping to one of an M3 and M4 grouping), if each mmW module had previously been operating at a 100% RF exposure margin, then when switching to an M2 grouping (e.g., from an LTE+FR2 call to an LTE+FR1 call) or one of an M3 and M4 grouping, the time history of all antenna groups in the M1 grouping may now exceed the RF exposure compliance limit. Therefore, various aspects of the present disclosure provide one or more criteria (referred to herein as "switching criteria") for switching between different groups, attempting to maximize or at least increase the benefits of switching while ensuring RF exposure compliance.

[0204] For example, assume that there are a total of "B" mmW groups in the M1 group (where all groups below 6 GHz are added to each mmW group) and there are "A" groups below 6 GHz in the M2 group (where all mmW groups are added to each group below 6 GHz). In this case, the total RF exposure margin available in the M1 group = 100% - (sub6_1 + sub6_2 + ... + sub6_A) - max{mmW_1, mmW_2, ..., mmW_B}, and the total RF exposure margin available in the M2 group = 100% - (mmW_1 + mmW_2 + ... + mmW_B) - max{sub6_1, sub6_2, ..., sub6_A}. The switching criteria for changing from the M1 group to the M2 group (e.g., LTE+FR2 call handover to LTE+FR1 call) may include the total available margin (TAM) in the M2 group being greater than the total available margin in the M1 group (TAM, M2>TAM, M1). Similarly, switching criteria for changing from M2 grouping to M1 grouping (eg, LTE+FR1 call handover to LTE+FR2 call) may include the total available margin in M1 grouping being greater than the total available margin in M2 grouping (TAM, M1 > TAM, M2).

[0205] The above example has only two different sets of antenna groups (M1 and M2 groupings). However, this concept and criteria for switching between antenna groups can be extended to more than two different groupings (e.g., also to M3 and M4, or using M3 and M4 instead of M2 in the above example). In general, the switching criteria for changing from one radio configuration to another may include that the total available margin in the new grouping is greater than the total available margin in the current (old) grouping.

[0206] In addition, the decision to switch between sets of antenna groups can be based on one or more criteria other than the total available margin. For example, in a combined transmission scenario of multiple sub-6 GHz radios and multiple mmW radios, the wireless communication device can use the priorities of the radios to select a particular set of antenna groups to operate with, thereby providing the highest priority radio with the largest total available margin. In other words, the wireless communication device can select to group the antennas associated with the highest priority radio into the largest number of antenna groups.

[0207] Return to Fig.10Operations 1000 may also involve the UE selecting a first grouping of the plurality of antenna groups based on one or more criteria. For certain aspects, the antenna group in block 1002 is in the first grouping, and the backoff factor in block 1002 is among a plurality of stored backoff factors for the first grouping and is associated with the antenna group in the first grouping. In this case, the one or more criteria may include a total RF exposure margin available for different groups in the plurality of antenna groups, including for the first grouping. For certain aspects, the one or more criteria may also include a priority of radio type.

[0208] According to certain aspects, operations 1000 may also involve the UE selecting a second grouping of the plurality of antenna groups based on one or more criteria; accessing another stored backoff factor associated with the antenna groups in the second grouping; and transmitting another signal from at least one transmit antenna in the antenna groups in the second grouping at another transmit power level based on the another backoff factor that complies with the RF exposure limit. In this case, the one or more criteria may include a total RF exposure margin available for different groups in the plurality of antenna groups (including for the first grouping and for the second grouping). In addition, when selecting the second grouping, the total RF exposure margin available for the second grouping may be greater than the total RF exposure margin available for the first grouping.

[0209] According to certain aspects, accessing at block 1002 may include accessing a first stored backoff factor associated with a first antenna group in a first group of the plurality of antenna groups. In this case, operations 1000 may also involve the UE accessing a second stored backoff factor associated with a second antenna group in a second group of the plurality of antenna groups based on one or more switching criteria.

[0210] For certain aspects, a wireless communication device (e.g., a UE) may select a specific antenna grouping, such as M1, M2, or one of several antenna groups, where all FR2 antennas are assigned to each antenna group and FR1 antennas are distributed between antenna groups, such that at least one of the FR1 antennas is assigned to multiple antenna groups (e.g., selected between M3 and M4). The wireless communication device may select antenna grouping for a specific transmission scenario, for example, as described herein with respect to operation 600 for grouping antennas to achieve RF exposure compliance. For example, when the wireless communication device is located in a specific region, the wireless communication device may select antenna grouping for the region. In some cases, the wireless communication device may select antenna grouping for a specific exposure scenario (e.g., when the wireless communication device is in close proximity to the user's head, arm, or abdomen). In some cases, the wireless communication device may select antenna grouping for a situation where certain antennas are used for concurrent transmission. In addition, the wireless device may select antenna grouping based on a combination of these factors (e.g., based on a specific region and the total available margin in the grouping corresponding to or usable within the specific region).

[0211] RF exposure per exposure scenario or category

[0212] As described herein, a wireless communication device may adjust certain RF exposure settings (e.g., backoff factors, antenna grouping, RF exposure limits, etc.) in response to changes in RF exposure scenarios (e.g., head exposure, body exposure, limb exposure, or hot spot exposure). A device state index (DSI) may represent or be associated with a specific RF exposure scenario, such that a specific DSI may refer to a specific RF exposure scenario. During regulatory certification, RF exposure may be characterized for different usage conditions or exposure scenarios (e.g., DSIs), including, for example, head exposure scenarios, body exposure scenarios (e.g., worn on the body or torso area), hot spot exposure scenarios (e.g., positioned on a table or desk away from the torso area), and limb exposure scenarios (hand / foot area that triggers a grip sensor). A limb may include, for example, any of a hand, wrist, foot, ankle, or auricle.

[0213] Depending on the use case, wireless communication devices may expose different human tissues or different parts of the human body to RF energy at different times over time. Fig.11 A diagram illustrating example wireless device positions 1104a-1104i (collectively, "positions 1104") relative to the shape of a user's body 1102 is illustrated. For example, in a first time period, the wireless device may be held near the user's head for voice calls (e.g., at positions 1104a, 1104b), where RF exposure is to the head; and in a second time period, the user may switch to using Bluetooth for voice calls and place the wireless device in a pocket (e.g., at positions 1104d, 1104g, 1104h), where RF exposure in the second time period is to both the head (from the Bluetooth radio) and the torso (from the wireless device). At other times, the user may position the wireless device in other positions, such as any of positions 1104c-1104i.

[0214] although Fig.11 Nine different locations 1104a-1104i are shown in FIG, but the reader should understand that there may be more or less than nine different locations for exposure to be assessed. The number of different locations for RF exposure tracking may depend on, for example, the sensing and / or memory capabilities of the wireless device, the desired tissue exposure tracking resolution, etc.

[0215] The RF exposure history may be tracked across different locations on the user's body as a function of time (and thus, the RF exposure history may also be referred to as "tissue exposure history"). The time-varying RF exposure may be recorded as a function of exposure f(exposure(i), t), where exposure(i) is the value of the exposure at time t for a particular tissue location (e.g., tissue i ) recorded exposure. tissue i A unique location (or region) may represent multiple locations or regions across a user's body. For example, a unique location may represent a specific tissue and / or part of the human body, such as the right or left side of a user's head; a specific hand, wrist, or arm (e.g., when the wireless device is positioned against the user's hand, wrist, or arm during exercise), a finger (e.g., when the wireless device is used for gaming), a torso (e.g., when the wireless device is in a pocket), etc. In some cases (as described herein), in order to track and record time-varying exposure history, exposed tissues may be grouped and classified into a certain number of exposure categories, and transmitting antennas may be grouped into different antenna groups. Each exposure category (described in more detail below) may be mutually exclusive of each other in terms of RF exposure over time, and each antenna group may transmit independently at a given time. For example, for a given time, the RF exposure of any antenna from one antenna group may not contribute to the RF exposure of antennas in other antenna groups.

[0216] In some aspects, tissue can be categorized by location on the user's body. The wireless device can track its location relative to the human body over time, for example using sensor information. i ) to track RF exposure. This method can be generalized to any tissue location on the user's body, where tissue i Can represent specific tissue locations in multiple dimensions, such as x i ,y i 、z i . Each tissue location (e.g., tissue i ) Perform time averaging of RF exposure. To demonstrate compliance, the time averaged RF exposure may be calculated and evaluated according to the following expression:

[0217]

[0218] time.averaged.RF.exposure≤regulatory limit

[0219] where T is the time window associated with the time-averaged RF exposure limit (e.g., 360 seconds, 100 seconds, 60 seconds, 3 seconds, etc.), and f(exposure(i),t) is the value of the exposure recorded at time t on the tissue iRF exposure encountered at Is to expose all tissue locations in history i ) exposure. In some cases, the wireless communication device may evaluate the time-averaged RF exposure within a time window, where the wireless communication device encounters different exposure scenarios during the time window. For example, during a first portion of the time window, the wireless communication device may be in a head exposure scenario (e.g., exp1), and during a second portion of the time window, the wireless communication device may be in a body-worn exposure scenario (e.g., exp2). In these cases, the different exposures may be correlated within the time window of the time-averaged RF exposure limit, such that the different exposures are evaluated in the same time-averaged function (e.g., f(exp1, exp2, t)) used to determine the available transmit power margin. This technique for determining the available transmit power margin may provide reduced wireless communication performance, for example, because the same RF exposure setting is applied to the time-averaged function even though there are different RF exposure scenarios.

[0220] Various aspects of the present disclosure provide techniques and apparatus for evaluating time-averaged RF exposure for each RF exposure scenario and / or RF exposure category. When the exposure DSI changes from head to body wear or vice versa, the exposure from the active radio may not expose the same tissue to RF energy, so the wireless communication device can take into account or account for the change in DSI when evaluating RF exposure compliance. For example, the time-averaged RF exposure encountered by the head exposure scenario can be evaluated separately from the time-averaged RF exposure encountered by the body wear exposure scenario, so that the RF exposure history of each RF exposure scenario can be tracked and evaluated separately, as further described herein. RF exposure time averaging can be performed for each exposure scenario or exposure category, which can include one or more exposure scenarios, as further described herein.

[0221] Techniques and apparatus for evaluating the time-averaged RF exposure for each RF exposure scenario or category may achieve desired wireless communication performance (e.g., reduced latency, increased throughput, increased transmission range, and / or increased signal quality or strength), for example, due to an increased transmit power margin available for transmission. Tracking RF exposure for each tissue location and / or region may allow a wireless device to transmit at a higher power level in scenarios where different locations on the user's body are exposed to RF transmissions for different time periods. For example, assume that the wireless device is positioned at location 1104a during a first time period and at location 1104g during a second time period. When the wireless device is positioned in different locations over time, the wireless device may be allowed to effectively restart time-averaged RF exposure compliance for each new location associated with the user's body. In other words, each tissue location may have a separate RF exposure history for tracking past transmissions.

[0222] Certain configurations are described herein for ensuring compliance with RF exposure limits across different tissues and / or locations on a user's body. As described above, some examples of tracking and recording time-varying exposure history include calculating or determining RF exposure based on tissues that have been grouped and / or classified into a certain number of exposure categories and / or based on transmit antennas grouped into different antenna groups. Other examples and configurations are also possible and are covered by the present disclosure.

[0223] In some examples, the SAR or PD value or distribution of a certain tissue is determined for each transmission. For example, SAR or PD measurements may be performed in a laboratory during transmission from each antenna for each potential tissue and / or position on the user's body (e.g., using a model or simulated tissue) and for each potential setting (e.g., RAT, modulation, frequency, etc.) that can be used to transmit on the antenna. In some aspects, a subset of these measurements is obtained, and the remaining measurements are determined using one or more of the above techniques. Tissues and / or positions may correspond to discrete points or positions (e.g., so that a grid of points covers the body), or may be defined as substantially continuous. For the purpose of RF exposure, each such tissue and / or position may be tracked separately. When a transmission is transmitted from an antenna, the exposure at the relevant tissue or position may be determined. In some examples, the exposure for each such transmission is determined separately without reference to an exposure category or antenna group. On the contrary, for each transmission, the exposure of all affected tissues / positions may be tracked (separately). However, in some examples, discrete points (as referenced above) may correspond to or be commensurate with DSI or other such position classifications. In some examples, each transmission is associated with a distribution of exposure values, and tissue across an area or part of the body (or multiple areas or parts, such as the head and hands) may experience RF exposure due to the transmission. As the transmitting device moves around, the distribution will also move and may vary due to the contours of the body or tissue types (and the distributions may partially or completely overlap), and thus the device (e.g., exposure manager 122, 281) can track all locations or tissues corresponding to the values ​​in the distribution (and may add or accumulate exposure at a particular tissue or location for the purpose of time averaging). Similarly, simultaneous or serial transmissions may expose the same or additional tissues, and exposure from each of these transmissions may be tracked for each tissue and / or location. Therefore, while the setup and operation of the device (e.g., UE 120) may be related to the determination of RF exposure, in some examples the exposure may be tracked (e.g., by the device) from a tissue-centric perspective.

[0224] As described above, aspects of ensuring RF exposure compliance across different tissues and / or locations on the user's body may include tracking and recording time-varying exposure histories for tissues and / or locations. In some cases, exposed tissues may be grouped and categorized into a number of exposure categories, and transmit antennas may be grouped into different antenna groups. Some examples including exposure categories and / or antenna groups are described below.

[0225] Fig.12 Example RF exposure time windows according to certain aspects of the present disclosure are illustrated, wherein RF exposure is evaluated separately for each RF exposure scenario and / or category. In this example, the exposure category may be divided into a head exposure category and a non-head exposure category, the head exposure category may include only a head exposure scenario (or multiple head exposure scenarios, such as a left cheek scenario, a right cheek scenario, a left tilt scenario, etc.), and the non-head exposure category may include body exposure, limb exposure, and / or hot spot exposure scenarios. In a first time sequence 1200A, a wireless communication device may encounter a head exposure scenario 1202 (exp1) and then switch to a non-head exposure scenario 1204 (exp2), such as a body exposure scenario. Examples include being in a voice call close to the head (head exposure scenario), and switching from a microphone to a Bluetooth-enabled call when the device is placed on a belt buckle (non-head exposure scenario). Here, the head exposure scenario is evaluated in a first time window T0, and the non-head exposure scenario is evaluated in a second time window T1 (which may overlap with the first time window T0). Here, T0 and T1 correspond to the supervision time averaging windows of the RF transmission in exp1 and exp2, respectively. Depending on whether the transmission frequency between exp1 and exp2 is the same or different, T0 and T1 may have the same or different time window lengths.

[0226] The wireless communication device may consider only the RF exposure attributable to the head exposure scenario (exp1) when determining the time-averaged RF exposure within the first time window T0. The time-averaged RF exposure in the first time window T0 may be calculated using the head exposure scenario (exp1) instead of the non-head exposure scenario (exp2). The wireless communication device may consider only the RF exposure attributable to the non-head exposure scenario (exp2) when determining the time-averaged RF exposure within the second time window T1. The time-averaged RF exposure in the second time window T1 may be calculated using the non-head exposure scenario (exp2) instead of the head exposure scenario (exp1). The exposure for the head scenario and the non-head scenario may not be correlated to determine the time-averaged RF exposure for each scenario. Therefore, the exposure categories may be mutually exclusive of each other in terms of RF exposure.

[0227] In the second time sequence 1200B, the wireless communication device may encounter a first head exposure scenario 1206 (exp1), switch to a non-head exposure scenario 1208 (exp2), and then switch back to a second head exposure scenario 1210 (exp3). For example, a voice call close to the user's head switches to a call with Bluetooth turned on as the device is located on a belt buckle, and then returns to a call with Bluetooth turned off when close to the user's head. Here, the head exposure scenario is evaluated in the first time window T0, and the non-head exposure scenario is evaluated in the second time window T1 (which may overlap with the first time window T0). The wireless communication device may only consider the RF exposure attributable to the head exposure (exp1) when determining the time-averaged RF exposure within the first time window T0. The wireless communication device may consider the RF exposure attributable to the non-head exposure (exp2) in the first evaluation of the time-averaged RF exposure within the second time window T1, and separately / independently consider the RF exposure attributable to the head exposure (exp1 and exp3) in the second evaluation of the time-averaged RF exposure within the second time window T1. Wireless communication may consider head and non-head exposure in separate time-averaged evaluations of RF exposure compliance. For example, the time average exposure of head DSI can be determined as a function of exp1 and / or exp3 within a moving time window (e.g., f(exp1, exp3, t)). The time average exposure of non-head DSI can be determined as a function of exp2 within a moving time window (e.g., f(exp2, t)).

[0228] Fig.13 Example RF exposure settings for certain exposure scenarios and / or exposure categories according to certain aspects of the present disclosure are illustrated, wherein P limit represents the time-averaged transmit power level corresponding to the RF exposure limit for a given exposure scenario / RAT / frequency band / antenna (e.g., after accounting for device uncertainty). limit Certain values ​​of (e.g., p0, p1, p2, p3, etc.) may be assigned to various exposure scenarios and / or exposure categories for each frequency band (e.g., B0, B1, B2, etc.) of a RAT (e.g., CDMA, LTE, NR, etc.) of an antenna (e.g., radio or antenna module) and / or antenna group. For example, for antenna 1 (or antenna group 1), the P value of p0 may be limit Assigned to different RAT / frequency bands of head exposure scenarios and / or head exposure categories, and can be P1 limit Assigned to non-head exposure categories and / or non-head exposure scenarios. For an antenna group (e.g., antenna group 1), P limit The value of can represent the P among the antennas in the antenna group limit The minimum value of . Fig.13 This example shows that different P limit (For example, p0-p23 ) is assigned to each combination of exposure scenario, exposure category, RAT, frequency band, antenna, and / or antenna group. However, in some examples, two or more combinations of P limit Can be the same.

[0229] Those skilled in the art will understand that Fig.13 The parameters illustrated in the example are only examples. Other parameters (e.g., backoff factors or P limit The power limit corresponding to the corresponding back-off factor multiplied by the corresponding combination of RAT, frequency band, exposure scenario, exposure category, antenna, antenna group, etc.) or parameter category (e.g., antenna group, antenna grouping or exposure classification).

[0230] In certain aspects, a wireless communication device may use specific antenna groupings for each exposure scenario and / or exposure category to assess the time-averaged RF exposure, for example, as described herein with respect to Figure 6 and Figure 7 As described, antenna groups are established for separate transmission scenarios. For example, various exposure scenarios can be grouped into certain categories, such that each exposure category is mutually exclusive with all other categories in terms of RF exposure. Since RF exposure for different DSIs is exposing different parts of the human body, for the purpose of RF exposure compliance, DSIs can be classified into different exposure categories, for example, assuming that different DSIs may be scenarios that expose different human tissues.

[0231] In some cases, the exposure continuum is divided into two categories, including head exposure and non-head exposure. For example, a first exposure category may include a head area (head DSI), and a second exposure category may include a non-head area (body-worn DSI, hotspot DSI, or limb DSI). The head exposure category may include exposure to the left cheek, left tilt, right cheek, and right tilt. The non-head exposure category may include other exposure scenarios (e.g., body-worn, hotspot, limb, etc.). For a given antenna and / or antenna group, it may be assumed that all exposures of the head exposure category or the non-head exposure category are juxtaposed or assigned to that particular antenna group, as described herein.

[0232] In some cases, the exposure continuum may be divided into three (or more) categories. For example, a first exposure category may include a head region (head DSI), a second exposure category may include a torso region (body-worn DSI, hotspot DSI), and a third exposure category may include a hand / foot region (limb DSI). All transmit antennas (e.g., radios or antenna modules) may be combined into one antenna group (e.g., assuming all antennas are juxtaposed) or assigned to different antenna groups for each exposure category. In some aspects, the exposure categories may provide a basis for grouping antennas into different antenna groups for certain DSIs, as further described herein.

[0233] The wireless communication device may perform time averaging for each exposure category for each antenna group. Once the DSI is classified into different exposure categories, the time averaged RF exposure may be evaluated for each exposure category by further classifying the transmit antennas into different antenna groups as described herein and performing time averaging for each antenna group. In certain aspects, for example, as described herein with respect to Fig.12 As described, RF exposure history may be tracked and stored separately for each exposure category for each antenna group, for example, because each exposure category may be mutually exclusive with respect to RF exposure, and each antenna group within each exposure category may be mutually exclusive with respect to RF exposure from other antenna groups within that exposure category. RF exposure for all exposure scenarios and / or categories may be tracked over time, such as available transmit power margin for future time intervals within a time window used to evaluate time-averaged RF exposure limits. Time-averaged RF exposure may be calculated only for active exposure scenarios (or categories) (e.g., when the UE is held in the user's hand and against the user's head, the head / limb DSI representing the head exposure category and the hand exposure category may be active). Among the time-averaged RF exposures for the active exposure categories, a minimum allowed transmit power value determined for each transmit antenna may be selected to limit the transmit power of the corresponding antenna and maintain compliance in the active exposure category. For example, in the above scenario where the UE is held in the user's hand and against the user's head, a power limit for transmitting according to the head DSI may be determined, and a power limit for transmitting according to the limb DSI may be determined, and the lower of the two determined power limits may be selected. The active exposure category may include one or more DSIs that occur within the time window of the time average RF exposure limit.

[0234] Fig.14 Various antenna groupings for exposure categories in accordance with certain aspects of the present disclosure are illustrated. In a first example exposure classification (or categorization) 1400A, there are four exposure categories (e.g., exposure category 1, exposure category 2, exposure category 3, and / or exposure category 4). Each exposure category may be associated with an antenna grouping having one or more antenna groups, where all antennas of a wireless communication device may be assigned across the antenna groups of each exposure category. For example, in exposure category 1, all antennas may be assigned across antenna group 1 and antenna group 2. In exposure category 2, all antennas may be assigned across antenna groups 5 to 8, and so on for other exposure categories.

[0235] In the second example exposure classification 1400B, there are also four exposure categories, with a single antenna group assigned to each of these categories. In this example, all antennas are assigned to the same antenna group. For example, it can be assumed that all antennas in a device overlap and the exposure of any antenna will also contribute (partially or completely) to the exposure of any other antenna. As another example, the transmissions from individual antennas can be spatially averaged or evaluated relative to how much the exposure from one antenna overlaps with the exposure from another antenna (e.g., not assuming that the antennas are mutually exclusive, but rather calculating the contribution between multiple antennas based on where they are located relative to each other and / or how their energy patterns overlap).

[0236] When the wireless communication device encounters a specific exposure scenario, the wireless communication device may use at least one of the antenna groups in the antenna group associated with the corresponding RF exposure scenario of the exposure category to evaluate the time-averaged RF exposure. For example, assume that the first exposure category corresponds to head exposure. If the wireless communication device encounters head exposure, the wireless communication device may select one of the antenna groups in the first exposure category (or multiple antenna groups in the case of a multi-transmit scenario) to evaluate the time-averaged RF exposure. If multiple exposure categories are active, for example, when the device is held by the hand (limb exposure category) and placed close to the head (head exposure category), then depending on the transmit antenna, the wireless communication device may select one or more active antenna groups for each active exposure category to evaluate the time-averaged RF exposure to determine the allowed power limit for future time intervals, thereby maintaining time-averaged RF exposure compliance. In this regard, the final allowed power limit for each transmit antenna may be determined to limit the transmit power of the wireless communication device, for example, by taking the minimum of all calculated allowed power limits obtained from evaluating all active antenna groups in all active exposure categories.

[0237] In certain aspects, the wireless device may evaluate the time-averaged RF exposure compliance for each combination of RF exposure scenarios and / or combinations of RF exposure categories. For example, the wireless device may consider RF exposure relative to hand exposure and head exposure in certain scenarios. For example, when the wireless device is held in the user's hand and against the head, the wireless device may consider the RF exposure history relative to the hand.

[0238] DSIs can be grouped into exposure categories such that each exposure category is mutually exclusive with all other categories in terms of RF exposure. During regulatory certification, RF exposure can be characterized for different conditions of use (DSIs): head, body worn (torso area), hot spot (torso area), and extremity (grip sensor trigger – hand / foot area). Since RF exposure for DSIs can expose different parts of the human body, RF exposure scenarios can be categorized into different categories.

[0239] Fig.15Example classifications 1500A, 1500B, 1500C of RF exposure categories are illustrated. As shown, a first classification 1500A (classification 0) may have a single category representing all exposure areas or scenarios (e.g., head DSI, body-worn DSI, hotspot DSI, and / or limb DSI). A second classification 1500B (classification 1) may have three exposure categories, including a first category representing head exposure (e.g., head DSI); a second category representing torso exposure (e.g., body-worn DSI and / or hotspot DSI); and a third category representing hand / foot areas (e.g., limb DSI). A third classification 1500C (classification 2) may have two exposure categories, including a first category representing head exposure (e.g., head DSI) and a second category representing non-head exposure (e.g., body-worn DSI, hotspot DSI, and / or limb DSI).

[0240] In the above classification, it is assumed that each exposure category is independent of other exposure categories. RF exposure control solutions (e.g., time-averaged RF exposure control solutions) can track exposure history for each exposure category independently to demonstrate time-averaged RF exposure compliance. This assumption sometimes ignores hand tissue exposure when the hand is also exposed to the handheld device in a head exposure scenario (e.g., head DSI).

[0241] In some aspects, the wireless device may consider hand exposure whenever head exposure activity is detected (e.g., head DSI is detected because the user may be holding the phone with their hand close to their head). RF exposure history may be tracked for each exposure category for each antenna group (assuming these histories are independent of each other). In the case of head DSI (because the hands may also be exposed), the wireless device may populate the exposure history for both the hands and the head, such as Fig.15 shown.

[0242] In the first category 1500A, past time-averaged history for all regions (e.g., head DSI, body-worn DSI, hotspot DSI, and / or limb DSI) may be combined to determine an exposure margin available for future transmissions (e.g., in terms of future transmit power) to maintain compliance with time-averaged RF exposure limits.

[0243] In the second category 1500B and the third category 1500C, in addition to the exposure history of hand exposure, the exposure history of hand exposure can also be filled in these categories together with the head exposure (for example, the head exposure is filled with the head and hand exposure). For active head exposure (for example, head DSI), the past time average history of both the head area and the hand area (non-head in the case of the third category 1500C) can be evaluated to determine the remaining exposure margin available for future transmissions, and the minimum value of the exposure margin can be used to calculate the future transmission power to maintain compliance in the hand area and the head area. This operation may be performed with twice the amount of calculations, that is, corresponding to the evaluation in the hand and head areas. It should be noted here that if either the torso DSI or the hand / limb DSI is active, the wireless device may evaluate only the exposure history of the torso area or the hand area, respectively.

[0244] In certain aspects, the wireless device may apply hand exposure to antenna groups and / or antenna groupings, as described herein. For a given exposure category (e.g., head or torso or hand, etc.), the transmit antennas may be divided into antenna groups that are mutually exclusive from an RF exposure perspective. Antenna groups may be formed based on a specific exposure category (such as head exposure, torso exposure, or hand exposure). In some cases, the antenna groups may be different between head exposure and hand exposure. Assuming that the wireless device (e.g., via an RF Exposure Control Solution (RFECS)) is unaware of the active antennas, but is aware of the active antenna groups, the wireless device may force the antenna groupings to be the same between head exposure and hand exposure, for example, as Fig.15 As described in Fig.15 As shown, the head exposure and hand exposure categories for the second classification 1500B may share the same antenna group, and the same applies to the third classification 1500C.

[0245] As further described herein (e.g., with respect to FIG. 16A to FIG. 19B ) Various techniques for considering hand exposure when head exposure is active. For example, under active head DSI conditions, the wireless device can populate the head exposure history with the maximum value (e.g., max{head exposure, hand exposure}) of the head exposure history and the hand exposure history of the active antenna group, and populate the same value (or hand exposure value) in the hand exposure history of the same antenna.

[0246] In some cases, assuming that the wireless device is aware of the active antennas (e.g., via RFECS), rather than just the active antenna groups, the wireless device may perform a hand exposure assessment for each antenna at any given time. Various techniques for considering hand exposure when head exposure is active as further described herein may be performed for each active antenna. The exposure history may be populated based on which antenna group is associated with the active antenna. For example, under an active head DSI condition, the wireless device may populate the head exposure history with the maximum value (e.g., max{head exposure, hand exposure}) of the head and hand exposure histories for a first antenna group (e.g., AG.x) corresponding to the active antennas, and the wireless device may populate the same value (or hand exposure value) in the hand exposure history for a second antenna group (e.g., AG.y) corresponding to the active antennas, if hand exposure is applicable, as further described herein. If hand exposure is not applicable, the wireless device may perform other operations described herein for each antenna group or each active antenna, such as those described herein with respect to FIG. 18A to FIG. 19B The operation described.

[0247] In some cases, the wireless device may use the maximum time-averaged transmit power level (P limit ) to perform RF exposure compliance. The operation based on the lookup table can take into account the hand exposure of active head exposure (e.g., head DSI). When the head exposure (e.g., head DSI) is active, the wireless device can take into account the past hand exposure history by converting the P of the head exposure into the P of the head exposure. limit The lookup table is replaced with the lowest (or minimum) of the maximum time-averaged power levels associated with head and hand exposures. limit (For example, min{P limit_head ,P limit_hand This operation may be equivalent to using the maximum exposure in the exposure history of head exposure and hand exposure for all antennas (eg, exposure = max{head exposure, hand exposure}), where the hand exposure is applicable to the head exposure scenario (eg, head DSI).

[0248] In certain aspects, the wireless device may separately track past exposure for each of the RF exposure scenarios (e.g., head exposure, hand exposure, and body exposure). When head exposure is active (e.g., when the wireless device is held in the user's hand close to the user's head), the wireless device may assess past exposure for head exposure and hand exposure.

[0249] FIG. 16A to FIG. 19B Depicted are timing diagrams of example RF exposure tracking for different exposure scenarios. Fig.16A1600A is a timing diagram illustrating the tracking of past RF exposures of head exposure, hand exposure, and body exposure over time, wherein hand exposure may be tracked when head exposure is active. In this example, when head exposure is active (e.g., exp1 and exp4), the wireless device may evaluate the head and hand exposure history to determine the allowed transmit power for each exposure scenario. For example, assume that the wireless device is located in position 1104a or 1104b with the user's hand. This operation may involve twice the amount of calculation, for example, calculating a first transmit power based on the head exposure history and calculating a second transmit power based on the hand exposure history. The wireless device may use the minimum transmit power of the determined allowed transmit power values ​​and apply the transmit power at the RF circuit (e.g., RF transceiver circuit 300). In body or hand exposure scenarios (e.g., exp2 and exp3), the wireless device may evaluate only the exposure history of body exposure or hand exposure, respectively. For example, assume that the wireless device is positioned in any one of positions 1104c-1104i.

[0250] For certain aspects, to reduce computations performed by the wireless device when head exposure is active, for each antenna (or radio), whenever hand exposure applies to the head exposure condition, the head exposure history may be populated with (or considered as) the maximum exposure of the head and hand exposures of the active head DSI (e.g., exposure = max{head exposure, hand exposure}). The hand exposure history may be considered as the past hand history of the active hand DSI (e.g., exposure = hand exposure). The head history may represent the worst case of the head and hand exposure histories. The hand exposure history may also be populated in the head exposure history when only the hand exposure is active. Tracking the hand exposure history in the head exposure history may allow the wireless device to account for the hand exposure when the head DSI is active.

[0251] Fig. 16B 1600B is a timing diagram illustrating the tracking of past RF exposures for head exposure, hand exposure, and body exposure over time, where an alternative method can be used to track hand exposure when head exposure is active. In this example, exp1 for head exposure is equal to the maximum exposure of head exposure and hand exposure (e.g., max{head exposure, hand exposure}), and exp1 for hand exposure is equal to hand exposure. exp4 for head and hand can be evaluated in the same manner. As shown, exp2 for hand is populated in the head exposure history when hand exposure is active.

[0252] For certain aspects, when the head is exposed to activity, the wireless device may use the same exposure history for head and hand tracking. Fig.17AAs shown in timing diagram 1700A of , the wireless device may determine the maximum value in the head and hand exposure history that tracks the head and hands over time. The head exposure may be equal to max{head exposure, hand exposure} for populating the head exposure history, and the same value may be copied (or applied) to the hand exposure history because the value represents a conservative exposure assessment of the hand exposure (e.g., a higher value than the actual exposure level).

[0253] In some aspects, since the head exposure condition may include hand exposure, the wireless device may set the maximum time-averaged power level (e.g., P) to which the head is exposed. limit_head ) is replaced with the lowest (or minimum) value among the head-hand exposure power levels of all antennas (or radios) for which hand exposure is applicable (e.g., min{Plimit_head, Plimit_hand}). For antennas for which hand exposure is not applicable (e.g., antennas near ears / audio speakers), the wireless device may continue to use the maximum time-averaged power level for head exposure. If the maximum time-averaged power levels are all static values, such operation may not frequently perform minimum evaluations. In this way, the wireless device is not as described herein with respect to Fig. 16B and Fig.17A Rather than determining the maximum exposure history as described above, the normalized head exposure may be determined as the power report divided by the minimum of the maximum time-averaged power levels of the head and hand exposures (e.g., power.report / min{Plimit_head,Plimit_hand}), e.g., as Fig. 17B 1700B. Head exposure tracking using max{head exposure, hand exposure} may be considered equivalent to max{power.report / Plimit_head,power.report / Plimit_hand} or power.report / min{Plimit_head,Plimit_hand}. A power report may correspond to a transmit power history over a period of time (e.g., a time window associated with a time-averaged RF exposure limit).

[0254] For certain aspects, the wireless device may consider hand exposure in certain scenarios, such as only when the wireless device is held by the user's hand next to the head and / or when RF exposure compliance considers hand exposure as well as head exposure. The wireless device may use the methods described herein (e.g., as described herein with respect to FIG. 16A to FIG. 17BThe hand exposure is applied to the head exposure assessment using any technique described in the previous section. For example, the wireless device may monitor exposure history for two categories: one for head exposure and another for non-head exposure (e.g., hand and body exposure). When the head DSI is active (e.g., the wireless device is held next to the hand), the hand exposure is also ensured to remain in steady-state conditions by replacing the head exposure with the maximum exposure of the head and hand exposures (e.g., head exposure = max{head exposure, hand exposure}). The maximum time-averaged power level (P limit_head ) is replaced with the minimum of the power levels for head and hand exposure for all antennas for which hand exposure is applicable (e.g., min{Plimit_head,Plimit_hand}). As described herein, for antennas for which hand exposure is not applicable (e.g., antennas near ears / audio speakers where it is assumed that the user's hands are positioned lower on the device, below such antennas, in order to hold the device), the wireless device continues to use the maximum time-averaged power level for head exposure, thereby keeping the power level unchanged.

[0255] Fig.18A 1800A is a timing diagram depicting evaluation of hand exposure along with head exposure when hand exposure is applicable (e.g., when a user's hand is near a transmit antenna and / or when RF exposure compliance considers hand exposure when the wireless device is held next to the user's head).

[0256] Fig.18B 1800B is a timing diagram depicting evaluation of head exposure without hand exposure when hand exposure is not applicable (e.g., when the user's hand is away from the transmit antenna or when the wireless device is positioned close to the user's head (e.g., in augmented reality (AR) and / or virtual reality (VR) applications where the wireless device can be strapped to or positioned close to the user's head) and the RF exposure compliance regulations do not consider hand exposure).

[0257] In some cases, hand exposure may not apply to some antennas when head exposure is active. For example, if the typical hand position of a user is toward the bottom of the wireless device when the handheld wireless device is held next to the user's hand, hand exposure may be considered when transmitting using antennas and / or antenna groups close to the hand. If the hand is away from certain antennas (e.g., antennas near the user's ear or audio speaker, at the upper part of the device), hand exposure may not apply, or reduced hand exposure may apply. Assuming that the RF exposure compliance regulations take hand exposure into account with head exposure, in this case, the hand exposure may be replaced by a specific exposure value (e.g., low.value) or limited to the specific exposure value. For example, the FCC stipulates that if the antenna is more than 25 mm from human tissue, 1g average SAR exposure = 0.4W / kg is used, and therefore the wireless device can use 0.4W / kg as the specific exposure value.

[0258] Fig.19A 1900A is a timing diagram depicting the evaluation of hand exposure along with head exposure when hand exposure is applicable. It should be understood that the wireless device may use any of the techniques described herein (e.g., with respect to FIG. 16A to FIG. 17A ) to consider hand exposure.

[0259] Fig.19B 1900B is a timing diagram depicting the evaluation of hand exposure along with head exposure when hand exposure is encountered from an antenna away from the user's hand. In this example, the wireless device may use hand exposure (Power Report / P limit_hand ) and a specific exposure value as the hand exposure (e.g., hand exposure = min{exp.hand, low.value}).

[0260] In some aspects, consideration of hand exposure in a head exposure scenario may depend on the standards or regulatory assessment procedures of a particular region. For example, one country may have an RF exposure assessment procedure that considers hand exposure in a head exposure scenario, while a different country may not have a procedure that considers hand exposure in a head exposure scenario. The wireless device may implement any of the techniques described herein to consider hand exposure in a head exposure scenario based on the region where the wireless device is located. For example, the wireless device may determine whether to consider hand exposure in a head exposure scenario based on various positioning information, such as an identifier of a wireless network (e.g., a mobile country code (MCC)), an address associated with an access point, or global positioning information. The wireless device may be configured with certain MCCs (or other location information) that indicate whether to evaluate hand exposure history when head exposure is active (e.g., when the wireless device is held next to the user's head by the user's hand).

[0261] Fig. 20 2 is a flow chart illustrating example operations 2000 for wireless communications in accordance with certain aspects of the present disclosure. Operations 2000 may be performed, for example, by a wireless communication device (e.g., UE 120a in wireless communication network 100). Operations 2000 may be implemented as a processor (e.g., Figure 2 In addition, the signal transmission performed by the wireless device in operation 2000 may be performed by one or more antennas (e.g., Figure 2 In some aspects, the transmission and / or reception of signals by the wireless device may be achieved by obtaining and / or outputting signals via a bus interface of one or more processors (eg, controller / processor 280).

[0262] Operations 2000 may begin at block 2002, where the wireless device may track multiple RF exposures over time across multiple locations associated with a human body (e.g., location 1104). The RF exposure may be tracked over time by the transmit power used in the locations, where a particular transmit power may correspond to an RF exposure level. To track RF exposure, the wireless device may track RF exposure across multiple exposure categories, such as described herein with respect to Figures 12 to 15 Described. Each exposure category may represent a different location in a plurality of locations (e.g., a specific location of human tissue, such as the left cheek) or a different set of locations (e.g., a plurality of locations, such as a non-head category). For example, an exposure category may include a head exposure category and a non-head exposure category. The head exposure category may correspond to the RF exposure encountered at the user's head, while the non-head exposure category may correspond to the RF exposure encountered at a non-head location, such as body exposure and / or limb exposure. In some cases, the exposure category may include separate categories for the left and right sides of the human body. For example, the head exposure category may be further divided into a left head exposure category (e.g., the left cheek) and a right head exposure category (e.g., the right cheek). The limb exposure category may be further divided into a left limb exposure category (e.g., the left hand) and a right hand exposure category (e.g., the right hand). In some cases, the limb exposure category may be further divided into exposure categories for each (or some) of the limbs (such as a separate hand, wrist, foot, ankle, or auricle).

[0263] At block 2004, the wireless device may provide a wireless signal based at least in part on a time average RF exposure limit (e.g., P limit ) and the transmit power determined by the tracked RF exposure. For example, the wireless device may send the signal to another wireless communication device (e.g., Figure 1 10 or any other wireless communication device depicted in ). The signal may indicate (or carry) any of a variety of information, such as data and / or control information. In some cases, the signal may indicate (or carry) one or more packets or data blocks.

[0264] In some aspects, the time window (e.g., Fig.12 The transmit power is determined based on a time-averaged exposure limit within any time window depicted in Figure 1 and the tracked RF exposure within the same time window. In some cases, the transmitted signal may be associated with an RF exposure distribution. The wireless device may determine a subset of the plurality of locations that experience RF exposure based on the distribution and outputs of one or more sensors of the wireless device (e.g., sensors that detect exposure scenarios or categories).

[0265] In some aspects, wireless devices may handle RF exposure tracking for different exposure categories independently of each other, for example, as described herein with respect to Fig.12Such processing of RF exposure associated with a particular exposure category may allow the wireless device to improve wireless communication performance, for example, when the wireless device exposes different locations of the human body to RF energy over time. The wireless device may identify an RF exposure history (e.g., a corresponding transmit power history) associated with a set of exposure categories in the tracked RF exposure (e.g., all of the exposure categories or a subset of the exposure categories that include one or more of the exposure categories). The RF exposure history may be in a moving time window associated with a time-averaged RF exposure limit (e.g., relative to the time window in this document). Fig.12 In response to detecting that the transmission of the signal will expose the set of locations to RF energy, the wireless device may determine a transmit power based at least in part on the RF exposure history and the time-averaged RF exposure limit. The set of locations may correspond to a set of exposure categories. To determine the transmit power, the wireless device may process the RF exposure history associated with the set of exposure categories independently of any RF exposure history associated with other exposure categories in the exposure category. For example, the wireless device may process the RF exposure history associated with head exposure independently of the RF exposure history associated with non-head exposure, as described herein with respect to Fig.12 as described.

[0266] In certain aspects, when determining transmit power to comply with RF exposure limits, a wireless device may consider (or take into account) RF exposures associated with multiple exposure categories (e.g., head-hand exposure), such as described herein with respect to FIG. 16A to FIG. 19B As described. When evaluating multiple exposure categories, the wireless device may consider (or take into account) the RF exposure associated with all exposure categories (e.g., when tracking RF exposure of head categories and non-head categories and the user's hands and the user's head are detected as being exposed to RF energy). For example, in some cases, the set of exposure categories may include more than one category. The set of exposure categories may include a first exposure category and a second exposure category different from the first exposure category. The first exposure category may correspond to RF exposure encountered in a first area of ​​the body (e.g., one or more first positions corresponding to the head), and the second exposure category may correspond to RF exposure encountered in a second area of ​​the body different from the first area of ​​the body (e.g., one or more second positions corresponding to a limb or hand). For example, the first exposure category may correspond to head exposure, for example, as a head exposure category, and the second exposure category may correspond to limb exposure, for example, as a limb exposure category. In some cases, the second exposure category may correspond to a specific limb, such as a hand and / or wrist. In some aspects, the first exposure category may correspond to exposure associated with a specific side of the head (e.g., the left side of the head), and the second exposure category may correspond to exposure associated with a specific hand (e.g., the left hand).

[0267] In some aspects, the wireless device may determine a transmit power for each exposure category in the set, and the wireless device may select a minimum (lowest) transmit power for transmitting the signal, e.g., as described herein with respect to Fig.16A To determine the transmit power, the wireless device may determine a first transmit power based at least in part on a first portion of the RF exposure history corresponding to a first exposure category, and determine a second transmit power based at least in part on a second portion of the RF exposure history corresponding to a second exposure category. The wireless device may select the transmit power as a minimum of the first transmit power and the second transmit power.

[0268] In some aspects, a wireless device may select a highest or maximum RF exposure level associated with a particular category among the multiple categories being evaluated, for example, as described herein with respect to Fig. 16B To identify the RF exposure history, the wireless device may select, for the RF exposure history, the highest (maximum) exposure among the tracked RF exposures for which the first exposure category and the second exposure category overlap in time.

[0269] For certain aspects, the wireless device may populate a first exposure category with a certain RF exposure history associated with a second exposure category in the plurality of categories, for example, as described herein with respect to Fig. 16B As described. For example, the RF exposure history populated into the first exposure category may correspond to when the second exposure category is active and when the first exposure category is inactive. To track RF exposure, the wireless device may track a first RF exposure history for the first exposure category, wherein the first RF exposure history includes one or more of the RF exposures associated with the first exposure category and the second exposure category, and the wireless device may track a second RF exposure history for the second exposure category, wherein the second RF exposure history includes one or more of the RF exposures associated with the second exposure category. To track the first RF exposure history, the wireless device may populate the first RF exposure history with a second RF exposure history, the second RF exposure history corresponding to when the first exposure category was inactive (and when the second exposure category was active), for example, when the RF exposure history associated with the first exposure category does not overlap in time with the RF exposure history associated with the second exposure category.

[0270] In some aspects, the wireless device may select the minimum (lowest) maximum time-averaged power level (P limit ), for example, as in this article relative to Fig. 17B To determine the transmit power, the wireless device may determine the transmit power based at least in part on the RF exposure history and a minimum of a first maximum time-averaged power level for the first exposure category and a second maximum time-averaged power level for the second exposure category. For example, the wireless device may use the minimum P value in the evaluated exposure category. limitTo determine the normalized RF exposure history, use the minimum P in the exposure category being evaluated. limit The wireless device may be permitted to transmit at a transmit power that complies with the RF exposure limits corresponding to the exposure category (eg, RF exposure limits for head and hand exposure).

[0271] For certain aspects, the wireless device may perform a multi-category assessment in response to detecting that the wireless device is located in a region that mandates such assessment. For example, to determine transmit power, the wireless device may further determine transmit power in response to detecting that the wireless device is located in a region that mandates assessing time-averaged RF exposure limits based on RF exposure histories associated with a first exposure category and a second exposure category (e.g., head and hand scenarios).

[0272] although Figures 1 to 20 The examples depicted in are described herein with respect to a UE that performs various methods for providing RF exposure compliance to facilitate understanding, but aspects of the present disclosure may also be applied to other wireless devices that perform the RF exposure compliance described herein, such as wireless stations, access points, base stations, and / or customer premises equipment (CPE). In addition, although these examples are described with respect to communications between a UE (or other wireless device) and a network entity, the UE or other wireless device may communicate with a device other than the network entity (e.g., another UE) or with another device in the user's home that is not a network entity. In addition, although certain examples are described with respect to a first exposure category and a second exposure category, the methods and configurations described herein may be applied to a larger number (e.g., three or more) of exposure scenarios and / or categories (e.g., a set of three or more locations and / or exposure categories).

[0273] It should be understood that the RF exposure assessed per exposure scenario or category may enable improved wireless communication performance, including, for example, increased throughput, reduced latency, increased transmission range, expected uplink performance, expected uplink data rate, uplink carrier aggregation, and / or uplink connectivity at the cell edge.

[0274] Example Communication Device

[0275] Fig.21 Examples include those that may be configured to perform operations such as Figure 6 and / or Fig.10100 (e.g., a wireless device, including UE 120) of the various components (e.g., corresponding to means plus function components) of the operations illustrated in . The communication device 2100 includes a processing system 2102 that can be coupled to a transceiver 2108 (e.g., a transmitter and / or a receiver). The transceiver 2108 is configured to transmit and receive signals for the communication device 2100 via an antenna 2110, such as various signals as described herein. The processing system 2102 can be configured to perform processing functions of the communication device 2100, including processing signals received and / or to be transmitted by the communication device 2100.

[0276] The processing system 2102 includes a processor 2104 coupled to a computer-readable medium / memory 2112 via a bus 2106. In some aspects, the computer-readable medium / memory 2112 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 2104, cause the processor 2104 to perform Figure 6 and / or Fig.10 2104, or other operations for performing the various techniques discussed herein for providing RF exposure compliance. In some aspects, the computer-readable medium / memory 2112 stores code for generating 2114, code for assigning 2116, code for accessing 2118, code for sending 2120, code for receiving (or obtaining) 2122, and / or code for determining (e.g., code for generating and / or code for receiving) 2124. In some aspects, the processing system 2102 has circuitry 2126 configured to implement the code stored in the computer-readable medium / memory 2112. In some aspects, the circuitry 2126 is coupled to the processor 2104 and / or the computer-readable medium / memory 2112 via the bus 2106. For example, circuit 2126 includes circuit 2128 for generating, circuit 2130 for assigning, circuit 2132 for accessing, circuit 2134 for sending, circuit 2136 for receiving (or obtaining) and / or circuit 2138 for determining (e.g., circuit for generating and / or circuit for receiving).

[0277] Fig. 22 Examples include those that may be configured to perform operations such as Fig. 202200 (e.g., a wireless device, including UE 120) of the various components (e.g., corresponding to the means plus function components) of the operations illustrated in . The communication device 2200 includes a processing system 2202 that can be coupled to a transceiver 2208 (e.g., a transmitter and / or a receiver). The transceiver 2208 is configured to transmit and receive signals for the communication device 2200 via an antenna 2210, such as various signals as described herein. The processing system 2202 can be configured to perform processing functions of the communication device 2200, including processing signals received and / or to be transmitted by the communication device 2200.

[0278] The processing system 2202 includes a processor 2204 (e.g., one or more processors) coupled to a computer readable medium / memory 2212 via a bus 2206. In some aspects, the computer readable medium / memory 2212 is configured to store instructions that, when executed by the processor 2204, cause the processor 2204 to execute instructions. Fig. 20 Instructions (e.g., computer executable code) for performing the illustrated operations or other operations of the various techniques discussed herein for providing RF exposure compliance. In some aspects, the computer-readable medium / memory 2212 stores code 2214 for tracking, code 2216 for sending, code 2218 for determining, code 2220 for selecting, or any combination thereof. In some aspects, the processing system 2202 has a circuit 2222 configured to implement the code stored in the computer-readable medium / memory 2212. In some aspects, the circuit 2222 is coupled to the processor 2204 and / or the computer-readable medium / memory 2212 via the bus 2206. For example, the circuit 2222 includes a circuit 2224 for tracking, a circuit 2226 for sending, a circuit 2228 for determining, a circuit 2230 for selecting, or any combination thereof.

[0279] Example aspects

[0280] Specific implementation examples are described in the following numbered clauses:

[0281] Aspect 1: A method of wireless communication by a wireless device, comprising: tracking multiple radio frequency (RF) exposures across multiple locations associated with a human body over time; and transmitting a signal at a transmit power determined at least in part based on a time-averaged RF exposure limit and the tracked RF exposures.

[0282] Aspect 2: A method according to aspect 1, wherein tracking the RF exposure includes tracking the RF exposure across multiple exposure categories, wherein each exposure category in the exposure category represents a different location or a different set of locations in the multiple locations associated with the human body.

[0283] Aspect 3: The method according to Aspect 2 also includes: identifying an RF exposure history associated with the set of exposure categories in the tracked RF exposure, wherein the RF exposure history is within a moving time window associated with the time-averaged RF exposure limit; and in response to detecting that the signal transmission will expose the set of multiple locations to RF energy, determining the transmission power based at least in part on the RF exposure history and the time-averaged RF exposure limit, wherein the set of multiple locations corresponds to the set of exposure categories.

[0284] Aspect 4: The method of aspect 3, wherein determining the transmit power comprises processing the RF exposure history associated with the set of exposure categories independently of any RF exposure history associated with other ones of the exposure categories.

[0285] Aspect 5: The method according to Aspect 3 or 4, wherein the set of exposure categories includes a first exposure category and a second exposure category different from the first exposure category.

[0286] Aspect 6: The method of aspect 5, wherein the first exposure category corresponds to head exposure, and wherein the second exposure category corresponds to limb exposure.

[0287] Aspect 7: The method of aspect 5, wherein the first exposure category corresponds to exposure associated with a particular side of the head, and wherein the second exposure category corresponds to exposure associated with a particular hand.

[0288] Aspect 8: A method according to any one of Aspects 5 to 7, wherein determining the transmit power includes: determining a first transmit power based at least in part on a first portion of the RF exposure history corresponding to the first exposure category; determining a second transmit power based at least in part on a second portion of the RF exposure history corresponding to the second exposure category; and selecting the transmit power as the minimum value of the first transmit power and the second transmit power.

[0289] Aspect 9: The method of any one of aspects 5 to 7, wherein identifying the RF exposure history comprises selecting, for the RF exposure history, a maximum exposure among the tracked RF exposures for which the first exposure category and the second exposure category overlap in time.

[0290] Aspect 10: A method according to any one of Aspects 5 to 9, wherein tracking the RF exposure comprises: tracking a first RF exposure history of the first exposure category, wherein the first RF exposure history includes one or more of the RF exposures associated with the first exposure category and the second exposure category; and tracking a second RF exposure history of the second exposure category, wherein the second RF exposure history includes one or more of the RF exposures associated with the second exposure category.

[0291] Aspect 11: The method of aspect 10, wherein tracking the first RF exposure history comprises populating the first RF exposure history with the second RF exposure history corresponding to when the first exposure category was inactive.

[0292] Aspect 12: A method according to any one of Aspects 5 to 7, wherein determining the transmit power includes determining the transmit power based at least in part on the RF exposure history and the minimum level of a first maximum time-averaged power level of the first exposure category and a second maximum time-averaged power level of the second exposure category.

[0293] Aspect 13: A method according to any one of Aspects 5 to 12, wherein determining the transmit power further includes determining the transmit power in response to detecting that the region in which the wireless device is located has regulations that evaluate the time-averaged RF exposure limit based on the RF exposure history associated with the first exposure category and the second exposure category.

[0294] Aspect 14: The method according to any one of aspects 1 to 13, wherein the transmit power is determined based on the time-averaged RF exposure limit within a time window and the tracked RF exposure within the same time window.

[0295] Aspect 15: A method according to any one of Aspects 1 to 14, wherein the transmitted signal is associated with an RF exposure distribution, and wherein the method further comprises determining a subset of the plurality of locations experiencing RF exposure based on the distribution and outputs of one or more sensors of the wireless device.

[0296] Aspect 16: An apparatus for wireless communication, comprising: a memory; and one or more processors coupled to the memory, the one or more processors being configured to: track multiple radio frequency (RF) exposures across multiple locations associated with a human body over time, and control a signal to be sent at a transmit power determined at least in part based on a time-averaged RF exposure limit and the tracked RF exposures.

[0297] Aspect 17: The apparatus according to Aspect 16 further includes a transmitter, which is coupled to the one or more processors, and the transmitter is configured to transmit the signal at the transmit power, wherein in order to track the RF exposure, the one or more processors are further configured to track the RF exposure across multiple exposure categories, and wherein each exposure category in the exposure category represents a different location or a different set of locations among the multiple locations associated with the human body.

[0298] Aspect 18: An apparatus according to Aspect 17, wherein the one or more processors are further configured to: identify an RF exposure history associated with the set of exposure categories in the tracked RF exposure, wherein the RF exposure history is within a moving time window associated with the time-averaged RF exposure limit; and in response to detecting that the signal transmission will expose the set of multiple locations to RF energy, determine the transmission power based at least in part on the RF exposure history and the time-averaged RF exposure limit, wherein the set of multiple locations corresponds to the set of exposure categories.

[0299] Aspect 19: An apparatus according to Aspect 18, wherein to determine the transmit power, the one or more processors are further configured to process the RF exposure history associated with the set of exposure categories independently of any RF exposure history associated with other exposure categories in the exposure categories.

[0300] Aspect 20: The apparatus of Aspect 18 or 19, wherein the set of exposure categories includes a first exposure category and a second exposure category different from the first exposure category.

[0301] Aspect 21: The apparatus of aspect 20, wherein the first exposure category corresponds to head exposure, and wherein the second exposure category corresponds to limb exposure.

[0302] Aspect 22: The apparatus of aspect 20, wherein the first exposure category corresponds to exposure associated with a particular side of the head, and wherein the second exposure category corresponds to exposure associated with a particular hand.

[0303] Aspect 23: An apparatus according to any one of Aspects 20 to 22, wherein, in order to determine the transmit power, the one or more processors are further configured to: determine a first transmit power based at least in part on a first part of the RF exposure history corresponding to the first exposure category, determine a second transmit power based at least in part on a second part of the RF exposure history corresponding to the second exposure category, and select the transmit power as the minimum value of the first transmit power and the second transmit power.

[0304] Aspect 24: An apparatus according to any one of Aspects 20 to 22, wherein, in order to identify the RF exposure history, the one or more processors are further configured to select, for the RF exposure history, a maximum exposure among the tracked RF exposures in which the first exposure category and the second exposure category overlap in time.

[0305] Aspect 25: An apparatus according to any one of Aspects 20 to 24, wherein in order to track the RF exposure, the one or more processors are further configured to: track a first RF exposure history of the first exposure category, wherein the first RF exposure history includes one or more of the RF exposures associated with the first exposure category and the second exposure category; and track a second RF exposure history of the second exposure category, wherein the second RF exposure history includes one or more of the RF exposures associated with the second exposure category.

[0306] Aspect 26: The apparatus of aspect 25, wherein to track the first RF exposure history, the one or more processors are further configured to populate the first RF exposure history with the second RF exposure history corresponding to when the first exposure category was inactive.

[0307] Aspect 27: An apparatus according to any one of Aspects 20 to 22, wherein, in order to determine the transmit power, the one or more processors are further configured to determine the transmit power based at least in part on the RF exposure history and the minimum level of a first maximum time-averaged power level of the first exposure category and a second maximum time-averaged power level of the second exposure category.

[0308] Aspect 28: An apparatus according to any one of Aspects 20 to 27, wherein in order to determine the transmit power, the one or more processors are further configured to determine the transmit power in response to detecting that the region in which the apparatus is located stipulates that the time-averaged RF exposure limit is evaluated based on the RF exposure history associated with the first exposure category and the second exposure category.

[0309] Aspect 29: An apparatus according to any one of aspects 16 to 28, wherein the transmit power is determined based on the time-averaged RF exposure limit within a time window and the tracked RF exposure within the same time window.

[0310] Aspect 30: An apparatus according to any one of Aspects 16 to 29, wherein the transmitted signal is associated with an RF exposure distribution, and wherein the one or more processors are further configured to determine a subset of the multiple locations experiencing RF exposure based on the distribution and the output of one or more sensors of the apparatus.

[0311] Aspect 31: An apparatus comprising: a memory comprising computer-executable instructions; and one or more processors, the one or more processors being configured to execute the computer-executable instructions and cause the apparatus to perform a method according to any one of Aspects 1 to 15.

[0312] Aspect 32: An apparatus comprising means for performing the method according to any one of aspects 1 to 15.

[0313] Aspect 33: A non-transitory computer-readable medium comprising computer-executable instructions, which, when executed by one or more processors of a processing system, cause the processing system to perform the method according to any one of aspects 1 to 15.

[0314] Aspect 34: A computer program product embodied on a computer-readable storage medium, comprising code for executing the method according to any one of aspects 1 to 15.

[0315] The techniques described herein may be used for various wireless communication technologies, such as NR (e.g., 5G NR), 3GPP Long Term Evolution (LTE), Advanced LTE (LTE-A), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), Time Division Synchronous Code Division Multiple Access (TD-SCDMA), and other networks. The terms "network" and "system" are often used interchangeably. A CDMA network may implement radio technologies such as Universal Terrestrial Radio Access (UTRA), cdma2000, and the like. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. cdma2000 covers IS-2000, IS-95, and IS-856 standards. A TDMA network may implement radio technologies such as Global System for Mobile Communications (GSM). OFDMA networks may implement radio technologies such as NR (e.g., 5G RA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, and the like. UTRA and E-UTRA are parts of the Universal Mobile Telecommunications System (UMTS). LTE and LTE-A are versions of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization named "3rd Generation Partnership Project" (3GPP). cdma2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). NR is an emerging wireless communication technology under development.

[0316] In 3GPP, the term "cell" can refer to the coverage area of ​​a Node B (NB) and / or a NB subsystem serving the coverage area, depending on the context in which the term is used. In NR systems, the terms "cell" and BS, next-generation NodeB (gNB or gNodeB), access point (AP), distributed unit (DU), carrier, or transmit receive point (TRP) can be used interchangeably. The BS can provide communication coverage for macro cells, pico cells, femto cells, and / or other types of cells. A macro cell can cover a relatively large geographic area (e.g., a radius of several kilometers) and can allow unrestricted access by UEs with service subscriptions. A pico cell can cover a relatively small geographic area and can allow unrestricted access by UEs with service subscriptions. A femto cell can cover a relatively small geographic area (e.g., a home) and can allow restricted access by UEs associated with a femto cell (e.g., UEs in a closed subscriber group (CSG), UEs of users in a home, etc.). A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS.

[0317] A UE as described herein may be configured as a mobile station, a terminal, an access terminal, a subscriber unit, a station, a customer premises equipment (CPE), a cellular phone, a smart phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet computer, a camera, a gaming device, a netbook, a smartbook, an ultrabook, an appliance, a medical device or medical equipment, a biometric sensor / device, a wearable device (such as a smart watch, smart clothing, smart glasses, a smart wristband, smart jewelry (e.g., a smart ring, a smart bracelet, etc.)), an entertainment device (e.g., a music device, a video device, a satellite radio, etc.), a transportation component or sensor, a smart meter / sensor, an industrial manufacturing equipment, a global positioning system device, or any other suitable device configured to communicate via a wireless or wired medium. Some UEs may be considered machine type communication (MTC) devices or evolved MTC (eMTC) devices. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc. that can communicate with a BS, another device (e.g., a remote device), or some other entity. A wireless node can provide, for example, a connection to or to a network (e.g., a wide area network such as the Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered Internet of Things (IoT) devices, which may be narrowband IoT (NB-IoT) devices.

[0318] In some examples, access to the air interface can be scheduled. A scheduling entity (e.g., BS) allocates resources for communications between some or all devices and equipment within its service area or cell. A scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communications, subordinate entities use resources allocated by the scheduling entity. The base station is not the only entity that acts as a scheduling entity. In some examples, a UE may be used as a scheduling entity and may schedule resources for one or more subordinate entities (e.g., one or more other UEs), and other UEs may utilize the resources scheduled by the UE for wireless communications. In some examples, a UE may be used as a scheduling entity in a peer-to-peer (P2P) network or in a mesh network. In a mesh network example, in addition to communicating with a scheduling entity, UEs may also communicate directly with each other.

[0319] The methods disclosed herein include one or more steps or actions for implementing the methods. The method steps and / or actions may be interchangeable with each other without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be modified without departing from the scope of the claims.

[0320] As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items (including single members). As an example, "at least one of a, b, or c" is intended to cover: a, b, c, ab, ac, bc, and abc, as well as any combination with multiple identical elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other ordering of a, b, and c).

[0321] As used herein, the term "determining" encompasses a wide variety of actions. For example, "determining" may include calculating, computing, processing, deriving, generating, investigating, searching (e.g., searching in a table, a database, or another data structure), ascertaining, and the like. Furthermore, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), and the like. Furthermore, "determining" may include resolving, selecting, choosing, establishing, and the like.

[0322] The preceding description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects. Therefore, the claims are not intended to be limited to the various aspects shown herein, but should be given the full scope consistent with the language of the claims, where, unless otherwise specified, references to elements in the singular form are not intended to mean "one and only one", but "one or more". Unless otherwise specified, the term "some" refers to one or more. All structural and functional equivalents of the elements of the various aspects described throughout the present disclosure that are known or will be known to a person of ordinary skill in the art are expressly incorporated herein by reference and are intended to be covered by the claims. In addition, nothing disclosed herein is intended to be dedicated to the public, whether or not such disclosure is explicitly stated in the claims. Any claim element should not be interpreted according to the provisions of 35 U.S.C. §112 (f), unless the element is explicitly stated using the phrase "member for...", or in the case of a method claim, the element is stated using the phrase "step for...".

[0323] The various operations of the above method can be performed by any suitable member capable of performing the corresponding function. The member may include various hardware and / or software components and / or modules, including but not limited to circuits, application specific integrated circuits (ASICs) or processors. Typically, where there are operations illustrated in the accompanying drawings, those operations may have corresponding corresponding members plus functional components with similar numbers.

[0324] The various illustrative logical blocks, modules, and circuits described in conjunction with the present disclosure may be implemented or executed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in an alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration.

[0325] If implemented in hardware, an example hardware configuration may include a processing system in a wireless node. The processing system may be implemented using a bus architecture. Depending on the specific application of the processing system and the overall design constraints, the bus may include any number of interconnecting buses and bridges. The bus may link various circuits together, including a processor, a machine-readable medium, and a bus interface. The bus interface may be used to connect a network adapter, etc., to the processing system via the bus. The network adapter may be used to implement signal processing functions at the physical (PHY) layer. In the UE (see Figure 1 ), a user interface (e.g., a keypad, display, mouse, joystick, etc.) may also be connected to the bus. The bus may also link various other circuits, such as timing sources, peripherals, voltage regulators, power management circuits, and the like, which are well known in the art and therefore will not be described further. The processor may be implemented using one or more general purpose processors and / or special purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuits that can execute software. Those skilled in the art will recognize how best to implement the described functionality of the processing system depending on the specific application and the overall design constraints imposed on the entire system.

[0326] If implemented in software, each function may be stored on or sent through a computer-readable medium as one or more instructions or codes. Software should be broadly interpreted as meaning instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or other. Computer-readable media include both computer storage media and communication media, including any medium that facilitates the transfer of computer programs from one place to another. The processor may be responsible for managing the bus and general processing, including executing software modules stored on a machine-readable storage medium. A computer-readable storage medium may be coupled to a processor so that the processor can read information from the storage medium and write information to the storage medium. In an alternative, the storage medium may be integral with the processor. For example, a machine-readable medium may include a transmission line, a carrier modulated by data, and / or a computer-readable storage medium having instructions stored thereon that is separated from a wireless node, all of which may be accessed by a processor through a bus interface. Alternatively or in addition thereto, a machine-readable medium or any part thereof may be integrated into a processor, such as in the case of having a cache and / or a general register stack. By way of example, examples of machine-readable storage media may include RAM (random access memory), flash memory, ROM (read only memory), PROM (programmable read only memory), EPROM (erasable programmable read only memory), EEPROM (electrically erasable programmable read only memory), registers, magnetic disks, optical disks, hard drives, or any other suitable storage media, or any combination thereof. Machine-readable media may be implemented in a computer program product.

[0327] A software module may include a single instruction, perhaps multiple instructions, and may be distributed over several different code segments, between different programs, and across multiple storage media. A computer-readable medium may include multiple software modules. A software module includes instructions that, when executed by a device such as a processor, cause a processing system to perform various functions. A software module may include a sending module and a receiving module. Each software module may reside in a single storage device or may be distributed across multiple storage devices. By way of example, when a triggering event occurs, a software module may be loaded from a hard drive into a RAM. During the execution of a software module, a processor may load some of the instructions into a cache to increase access speed. One or more cache lines may then be loaded into a general register stack for execution by the processor. When the functionality of a software module is mentioned below, it will be understood that such functionality is implemented by the processor when executing instructions from the software module.

[0328] Additionally, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technology such as infrared (IR), radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technology such as infrared, radio, and microwave are included in the definition of medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Optical disks, where magnetic disks typically reproduce data magnetically, and optical disks use lasers to reproduce data optically. Thus, in some aspects, computer-readable media may include non-transitory computer-readable media (e.g., tangible media). Additionally, for other aspects, computer-readable media may include transient computer-readable media (e.g., signals). Combinations of the above should also be included within the scope of computer-readable media.

[0329] Thus, certain aspects may include a computer program product for performing the operations presented herein. For example, such a computer program product may include a computer-readable medium having instructions stored (and / or encoded) thereon, the instructions being executable by one or more processors to perform the operations described herein, such as for performing the operations described herein and in Figure 6 , Fig.10 and / or Fig. 20 Instructions for the operations illustrated in .

[0330] In addition, it should be understood that the modules and / or other appropriate components for executing the methods and techniques described herein can be downloaded and / or otherwise obtained by the user terminal and / or base station where applicable. For example, such a device can be coupled to a server to facilitate the transfer of components for executing the methods described herein. Alternatively, the various methods described herein can be provided via a storage component (e.g., RAM, ROM, or a physical storage medium such as a compact disc (CD) or a floppy disk) so that the user terminal and / or base station can obtain the various methods when the storage component is coupled to or provided to the device. In addition, any other appropriate technology for providing the methods and techniques described herein to the device can be used.

[0331] It is to be understood that the claims are not limited to the precise configuration and components illustrated above. Various modifications, changes and variations may be made in the arrangement, operation and details of the methods and apparatus described above without departing from the scope of the claims.

Claims

1. A method for wireless communication by a wireless device, comprising: Tracking multiple radio frequency (RF) exposures across multiple locations associated with a human body over time; as well as A signal is transmitted at a transmit power determined based at least in part on the time average RF exposure limit and the tracked RF exposure.

2. The method of claim 1 , wherein tracking the RF exposure comprises tracking the RF exposure across a plurality of exposure categories, wherein each of the exposure categories represents a different location or a different set of locations of the plurality of locations associated with the human body.

3. The method according to claim 2, further comprising: identifying an RF exposure history associated with the set of exposure categories in the tracked RF exposures, wherein the RF exposure history is within a moving time window associated with the time-averaged RF exposure limit; as well as In response to detecting that the signal transmission will expose the set of the plurality of locations to RF energy, the transmission power is determined based at least in part on the RF exposure history and the time-averaged RF exposure limit, wherein the set of the plurality of locations corresponds to the set of exposure categories. 4 . The method of claim 3 , wherein determining the transmit power comprises processing the RF exposure history associated with the set of exposure categories independently of any RF exposure history associated with other ones of the exposure categories. The method of claim 3 , wherein the set of exposure categories includes a first exposure category and a second exposure category different from the first exposure category.

6. The method of claim 5, wherein the first exposure category corresponds to head exposure, and wherein the second exposure category corresponds to limb exposure.

7. The method of claim 5, wherein the first exposure category corresponds to exposure associated with a particular side of the head, and wherein the second exposure category corresponds to exposure associated with a particular hand.

8. The method of claim 5, wherein determining the transmit power comprises: determining a first transmit power based at least in part on a first portion of the RF exposure history corresponding to the first exposure category; determining a second transmit power based at least in part on a second portion of the RF exposure history corresponding to the second exposure category; as well as The transmission power is selected as a minimum value between the first transmission power and the second transmission power. 9 . The method of claim 5 , wherein identifying the RF exposure history comprises selecting, for the RF exposure history, a maximum exposure among the tracked RF exposures for which the first exposure category and the second exposure category overlap in time.

10. The method of claim 5, wherein tracking the RF exposure comprises: tracking a first RF exposure history for the first exposure category, wherein the first RF exposure history includes one or more of the RF exposures associated with the first exposure category and the second exposure category; and A second RF exposure history for the second exposure category is tracked, wherein the second RF exposure history includes one or more of the RF exposures associated with the second exposure category. 11 . The method of claim 10 , wherein tracking the first RF exposure history comprises populating the first RF exposure history with the second RF exposure history corresponding to when the first exposure category was inactive.

12. The method of claim 5, wherein determining the transmit power comprises determining the transmit power based at least in part on the RF exposure history and a minimum of a first maximum time-averaged power level for the first exposure category and a second maximum time-averaged power level for the second exposure category.

13. The method of claim 5, wherein determining the transmit power further comprises determining the transmit power in response to detecting that a region in which the wireless device is located has regulations that evaluate the time-averaged RF exposure limit based on the RF exposure history associated with the first exposure category and the second exposure category.

14. The method of claim 1, wherein the transmit power is determined based on the time-averaged RF exposure limit within a time window and the tracked RF exposure within the same time window.

15. The method of claim 1, wherein the transmitted signal is associated with an RF exposure distribution, and wherein the method further comprises determining a subset of the plurality of locations experiencing RF exposure based on the distribution and outputs of one or more sensors of the wireless device.

16. An apparatus for wireless communication, comprising: Memory; and one or more processors, the one or more processors coupled to the memory, the one or more processors configured to: Tracking multiple radio frequency (RF) exposures across multiple locations associated with the human body over time, and Control is provided to transmit a signal at a transmit power determined based at least in part on the time average RF exposure limit and the tracked RF exposure.

17. The apparatus of claim 16, further comprising a transmitter coupled to the one or more processors, the transmitter configured to transmit the signal at the transmit power, wherein to track the RF exposure, the one or more processors are further configured to track the RF exposure across multiple exposure categories, and wherein each of the exposure categories represents a different location or a different set of locations among the multiple locations associated with the human body.

18. The apparatus of claim 17, wherein the one or more processors are further configured to: identifying an RF exposure history associated with the set of exposure categories in the tracked RF exposures, wherein the RF exposure history is within a moving time window associated with the time-averaged RF exposure limit; and In response to detecting that the signal transmission will expose the set of the plurality of locations to RF energy, the transmission power is determined based at least in part on the RF exposure history and the time-averaged RF exposure limit, wherein the set of the plurality of locations corresponds to the set of exposure categories.

19. The apparatus of claim 18, wherein to determine the transmit power, the one or more processors are further configured to process the RF exposure history associated with the set of exposure categories independently of any RF exposure history associated with other exposure categories in the exposure categories.

20. The apparatus of claim 18, wherein the set of exposure categories includes a first exposure category and a second exposure category different from the first exposure category.

21. The apparatus of claim 20, wherein the first exposure category corresponds to head exposure, and wherein the second exposure category corresponds to limb exposure.

22. The apparatus of claim 20, wherein the first exposure category corresponds to exposure associated with a particular side of the head, and wherein the second exposure category corresponds to exposure associated with a particular hand.

23. The apparatus of claim 20, wherein to determine the transmit power, the one or more processors are further configured to: determining a first transmit power based at least in part on a first portion of the RF exposure history corresponding to the first exposure category, determining a second transmit power based at least in part on a second portion of the RF exposure history corresponding to the second exposure category, and The transmission power is selected as a minimum value between the first transmission power and the second transmission power.

24. The apparatus of claim 20, wherein to identify the RF exposure history, the one or more processors are further configured to select, for the RF exposure history, a maximum exposure among the tracked RF exposures in which the first exposure category and the second exposure category overlap in time.

25. The apparatus of claim 20, wherein to track the RF exposure, the one or more processors are further configured to: tracking a first RF exposure history for the first exposure category, wherein the first RF exposure history includes one or more of the RF exposures associated with the first exposure category and the second exposure category; and A second RF exposure history for the second exposure category is tracked, wherein the second RF exposure history includes one or more of the RF exposures associated with the second exposure category.

26. The apparatus of claim 25, wherein to track the first RF exposure history, the one or more processors are further configured to populate the first RF exposure history with the second RF exposure history corresponding to when the first exposure category was inactive.

27. An apparatus according to claim 20, wherein to determine the transmit power, the one or more processors are further configured to determine the transmit power based at least in part on the RF exposure history and a minimum of a first maximum time-averaged power level for the first exposure category and a second maximum time-averaged power level for the second exposure category.

28. An apparatus according to claim 20, wherein, in order to determine the transmit power, the one or more processors are further configured to determine the transmit power in response to detecting that the region in which the apparatus is located stipulates that the time-averaged RF exposure limit is evaluated based on the RF exposure history associated with the first exposure category and the second exposure category.

29. The apparatus of claim 16, wherein the transmit power is determined based on the time-averaged RF exposure limit within a time window and the tracked RF exposure within the same time window.

30. The apparatus of claim 16, wherein the transmitted signal is associated with an RF exposure distribution, and wherein the one or more processors are further configured to determine a subset of the plurality of locations experiencing RF exposure based on the distribution and an output of one or more sensors of the apparatus.

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