Multi-radio transmission adjustment for time-averaged radio frequency exposure

Abstract

Certain aspects of the present disclosure provide techniques and apparatus for multi-radio transmission scaling. A method executable by a wireless device includes obtaining scaling information indicating a relationship between a first radio frequency (RF) exposure associated with a plurality of first radios and a second RF exposure associated with a single second radio; and transmitting, using the plurality of radios, a signal at one or more transmit powers determined based at least in part on the time-averaged RF exposure limit and the scaling information.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. patent application serial number 18 / 326,913 filed on May 31, 2023, which claims the benefit and priority of U.S. Provisional Application No. 63 / 365,695 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 compliance.

[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 devices, such as cellular phones, are often required to meet radio frequency (RF) exposure limits set by certain government 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. To ensure that wireless devices comply with RF exposure limits, technologies have been developed that enable wireless devices to assess RF exposure from the wireless device and adjust the transmit power of the wireless 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 one of which is solely responsible for its desirable characteristics. Without limiting the scope of the present disclosure as expressed in the appended claims, some features will now be briefly discussed. After considering this discussion, and particularly after reading the section entitled "Detailed Description," one will understand how the features of the present disclosure provide advantages, including improved wireless communication performance.

[0007] Certain aspects of the subject matter described in this disclosure may be implemented in a method for wireless communications by a wireless device. The method generally includes: obtaining scaling information indicating a relationship between a first radio frequency (RF) exposure associated with a plurality of first radios and a second RF exposure associated with a single second radio; and transmitting signals using the plurality of radios at one or more transmit powers determined at least in part based on a time average RF exposure limit and the scaling information.

[0008] Certain aspects of the subject matter described in this disclosure may be implemented in an apparatus for wireless communication. The apparatus generally includes a memory and one or more processors coupled to the memory. The one or more processors are configured to: obtain scaling information indicating a relationship between a first radio frequency (RF) exposure associated with a plurality of first radios and a second RF exposure associated with a single second radio; and transmit signals using the plurality of radios at one or more transmit powers determined at least in part based on a time-averaged RF exposure limit and the scaling information.

[0009] Certain aspects of the subject matter described in this disclosure may be implemented in an apparatus for wireless communication. The apparatus generally includes means for obtaining scaling information indicating a relationship between first radio frequency (RF) exposures associated with a plurality of first radios and second RF exposures associated with a single second radio; and means for transmitting signals using the plurality of radios at one or more transmit powers determined at least in part based on a time-averaged RF exposure limit and the scaling information.

[0010] Certain aspects of the subject matter described in this disclosure may be implemented in a computer-readable medium having instructions stored thereon that, when executed by an apparatus, cause the apparatus to perform operations including: obtaining scaling information indicating a relationship between first radio frequency (RF) exposures associated with a plurality of first radios and second RF exposures associated with a single second radio; and transmitting signals using the plurality of radios at one or more transmit powers determined at least in part based on a time-averaged RF exposure limit and the scaling information.

[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 2is 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 4A , Figure 4B and Figure 4C is a graph illustrating an example of transmit power over time subject to time-averaged RF exposure limits in accordance with certain aspects of the present disclosure.

[0017] Figure 5 is a table illustrating example maximum RF exposure levels measured for specific wireless devices.

[0018] Figure 6 illustrates example (normalized) transmit power versus time relative to the maximum time-averaged transmit power level (P limit ) curve graph.

[0019] Figure 7 is a flow chart illustrating example operations for ensuring compliance with time-averaged RF exposure limits.

[0020] Figure 8 illustrates example (normalized) transmit power versus time relative to the maximum time-averaged transmit power level (P limit ) where scaling information is used to scale the reported transmit power and the maximum allowed transmit power.

[0021] Fig. 9 is a flow diagram illustrating example operations for ensuring compliance with RF exposure limits, where scaling information may be used to adjust certain margins and / or reservations.

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

[0023] Fig.11 Illustrated is a communications device (eg, UE) that may include various components configured to perform operations for the techniques disclosed herein in accordance with certain aspects of the present disclosure.

[0024] 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

[0025] Aspects of the present disclosure provide apparatus, methods, processing systems, and computer-readable media for adjusting transmit power to comply with radio frequency (RF) exposure in a multi-radio transmit scenario.

[0026] In some cases, the wireless device may evaluate the RF exposure within a given time window in real time to determine the maximum allowed transmit power (e.g., P) for a given time interval based on past transmission history. max ) to ensure that the maximum time-averaged transmit power level (e.g., P limit ). In some aspects, the wireless device may be configured to transmit a signal according to P in a single radio transmission scenario. limit ) for transmitting at an RF exposure design target level (e.g., where only a single radio is transmitting). For compliance purposes, the RF exposure design target level may be at least below the RF exposure compliance limit after subtracting the uncertainty associated with the wireless device (e.g., k=2) (95% confidence), so that the wireless device can be guaranteed to be compliant when operating even at a certain uncertainty level (e.g., k=2). This approach is typically followed for mass-produced wireless devices so that compliance is guaranteed with 95% confidence. The RF exposure design target level for certain radios (e.g., sub-6 GHz radios) may be selected to be much lower than this level (e.g., the RF exposure compliance limit after subtracting device uncertainty). In some cases, a wireless device may use a maximum time-averaged transmit power level (e.g., P limit ) to ensure compliance with RF exposure compliance limits, where wireless devices may only allow less than or equal to P limit The lookup table based solution and the time averaging solution may perform similarly in maximizing the transmit power for a single radio transmit scenario (e.g., where only a single radio is transmitting). In a multi-radio transmit scenario (e.g., where multiple radios transmit simultaneously or in the same time interval), the lookup table based solution may operate such that the maximum total exposure from the active radios is close to the RF exposure compliance limit (e.g., the maximum total exposure is greater than the RF exposure design target level plus the wireless device uncertainty). In the same multi-radio transmit scenario, the time averaging solution may operate such that the maximum total time average exposure from the active radios is less than or equal to the RF exposure design target level plus the device uncertainty. In other words, the lookup table based solution may enable the wireless device to transmit at a higher total power level than the time averaging solution in a multi-radio transmit scenario.

[0027] Various aspects of the present disclosure provide apparatus and methods for adjusting transmit power in time-averaged RF exposure operations in multi-radio transmit scenarios. In some cases, a wireless device may adjust the maximum time-averaged power level (e.g., P) of each active radio based on certain scaling information. limit ), as further described herein. For example, the scaling information may indicate an amount to increase transmit power in a multi-radio transmit scenario relative to a single-radio transmit scenario, as further described herein. In some cases, the wireless device may adjust past transmit power history and / or maximum allowed transmit power based on the scaling information, as further described herein. In a multi-radio transmit scenario, the scaling information may enable the wireless device to operate at a time-averaged RF exposure level that is close to an RF exposure limit, which may be set, for example, according to a regulatory agency or standards organization.

[0028] The apparatus and methods for transmit power adjustment described herein can facilitate improved wireless communication performance (e.g., lower latency and / or higher throughput). For example, transmit power adjustment can allow a wireless device to transmit at a transmit power close to a time-averaged RF exposure limit in a multi-radio transmission scenario.

[0029] As used herein, a "radio" may refer to a physical or logical transmission path associated with one or more active frequency bands (carriers, channels, bandwidths, subdivisions thereof, etc.), transceivers, and / or radio access technologies (RATs) (e.g., code division multiple access (CDMA), long term evolution (LTE), new radio (NR), IEEE 802.11, Bluetooth, etc.) for wireless communications. For example, for uplink carrier aggregation in LTE and / or NR, each of the active component carriers used for wireless communications may be considered a separate radio. Similarly, multi-band transmissions for IEEE 802.11 communications may be considered a separate radio for each frequency band (e.g., 2.4 GHz, 5 GHz, or 6 GHz). As used herein, a "multi-radio transmission scenario" may also be referred to as a simultaneous transmission scenario, in which multiple radios (e.g., NR and IEEE 802.11 radios) transmit simultaneously for a specific duration or transmit within the same time interval, such as a time interval associated with a time averaging time window for a time averaged RF exposure limit.

[0030] 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 process 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 devices or methods practiced using other structures, functions, or structures and functions that are supplementary or alternative to the various aspects of the present disclosure set forth 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] Example Wireless Communications Networks and Devices

[0035] 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 in accordance with 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 uses scaled transmit power to ensure RF exposure compliance, in accordance with aspects of the present disclosure.

[0036] like Figure 1 As illustrated in , the wireless communication network 100 may include multiple BSs 110a to 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 with 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 1In 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.

[0037] BS 110 communicates with UEs 120a-y (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.

[0038] The network controller 130 may communicate with a collection 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 open functions, network repository functions, network slice selection functions, etc.

[0039] Figure 2 1 and 120a (eg, Figure 1 Example components of a wireless communication network 100).

[0040] 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).

[0041] 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 transceivers 232a-232t. Each modulator in transceivers 232a to 232t may process a corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator in transceivers 232a to 232t may further process (e.g., transform 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.

[0042] At UE 120a, antennas 252a-252r may receive downlink signals from BS110a 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.

[0043] 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 reference signals (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.

[0044] 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.

[0045] 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 represents the RF exposure manager 122, in accordance with 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.

[0046] 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).

[0047] Although the reference 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 directly 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 .

[0048] Example RF Transceiver

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] Controller 336 may direct the operation of RF transceiver circuit 300, such as transmitting signals via TX path 302 and / or receiving signals via RX path 304. 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. Memory 338 may store data and program code for operating RF transceiver circuit 300. Controller 336 and / or memory 338 may include control logic. In some cases, controller 336 may determine the transmit power applied to TX path 302 (e.g., certain gain levels applied at BBF 312, DA 316, and / or PA 318) in compliance with RF exposure limits set, for example, by country-specific regulations and / or international standards, as further described herein.

[0055] Example RF Exposure Compliance

[0056] RF exposure can be expressed in terms of the 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 milliwatts per square centimeter (mW / cm 2 ) units. In some cases, a maximum permissible exposure (MPE) limit (in the form of PD) may be imposed on wireless 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.

[0057] 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.

[0058] A wireless device (e.g., UE 120) may use multiple wireless communication technologies to send signals simultaneously. For example, a wireless 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 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.

[0059] In some cases, compliance with RF exposure limits may be performed as a time-averaged RF exposure assessment over a specified time window (T) associated with the RF exposure limit (e.g., 2 seconds for the 60 GHz band, 100 or 360 seconds for bands ≤ 6 GHz, etc.). Figure 4A 4 is a graph 400A of transmit power (P(t)) over time within a running (also referred to as rolling or moving) time window (T) associated with an RF exposure limit in accordance with certain aspects of the present disclosure. As an example, during certain transmission opportunities within the time window (T), the instantaneous transmit power may exceed the maximum time-averaged transmit power level P(t). limit That is, the transmission power can be greater than the maximum time average transmission power level P limit In some cases, the UE can P max_tx The maximum transmission power supported by the UE, the maximum instantaneous transmission power that the wireless device can output, and / or the maximum instantaneous transmission power allowed by the standard or regulatory agency (for example, the maximum output power P CMAX ). In some cases, during certain transmission occasions, the UE may be less than or equal to the maximum time-averaged transmission power level P limit The maximum time average transmit power level P limit represents the time-averaged threshold value in terms of transmit power for RF exposure limit within a time window (T), and in some cases, P limitThis may be referred to as a maximum time average power level or limit, or in terms of exposure, a maximum time average RF exposure level or limit. Graph 400A also illustrates gaps between transmit bursts, where these gaps represent periods during which no transmission is being output from the device.

[0060] In some cases, the transmit power may be maintained at a maximum time-averaged transmit power level (e.g., P) allowed for RF exposure compliance that enables continuous transmission during the time window. limit ).For example, Figure 4B is a graph 400B of transmit power (P(t)) over time, illustrating a case where the transmit power is limited to P in accordance with certain aspects of the present disclosure. limit As shown in the figure, the UE can follow the RF exposure limit to P limit Send continuously.

[0061] Figure 4C 400C is a graph of transmit power (P(t)) over time illustrating a time-averaged mode that provides reserved power to enable continuous transmission within a time window (T) in accordance with certain aspects of the present disclosure. As shown, the transmit power may be increased from a maximum instantaneous power (P max_tx ) falls back to the reserved power (P reserve ), so that the UE can continue to operate at a lower power (P reserve ) to maintain continuous transmission (e.g., maintain a radio connection with the receiving entity) during the time window. Figure 4C In P max_tx The duration between P max_tx With P reserve The area between can be equal to the area between P and limit With P reserve The area between Figure 4C The area of ​​the transmitted power (P(t)) in the time window T is equal to P limit This area can be considered to use 100% of the energy (transmitted power or exposure) to maintain compliance with the time-averaged RF exposure limit. reserve In the case of max_tx The transmitter is turned off during the remainder of the time window to ensure compliance with time-averaged RF exposure limits. reserve Set to a fixed power serving a certain purpose (e.g., reserving power for certain communications) or to such a fixed power plus a margin. max_txThe transmission duration under P may be referred to as the burst transmission time (or high power duration). When more margin is available in the future (after T seconds), the transmitter may be allowed to transmit again at a higher power (e.g., at P max_tx (sent in short bursts below).

[0062] In some respects, Figure 4C In the time average mode illustrated in FIG, the UE can be above the average power level but less than P max_tx Although Figure 4C A single transmit burst is illustrated in FIG. 1 , but it should be understood that the UE may alternatively utilize multiple transmit bursts within the time window (T), such as described herein with respect to Figure 4A The transmit bursts may be maintained at a transmit power equal to or lower than P reserve In addition, it should be understood that the transmit power of each transmit burst may vary (within a burst and / or compared to other bursts), and at least a portion of the burst may be above a maximum average power level (e.g., P limit ) power to send.

[0063] Although FIG. 4A to FIG. 4C Continuous transmission within a window, opportunity, burst, etc. is illustrated, but it should be understood that a transmission duty cycle may be implemented. In such implementations, the transmit power may be periodically zero and maintained at a higher level during one or more other portions of the duty cycle (e.g., FIG. 4A to FIG. 4C exemplified in ). The duty cycle of a transmission may indicate a portion (e.g., 5 ms) of a specific time period (e.g., 500 ms) in which one or more signals are transmitted. The duty cycle may be a ratio of the length of time of the portion to the specific time period (e.g., 100 ms / 500 ms), where the duty cycle may be represented as a number from zero to one. In some cases, the duty cycle may be standardized (e.g., predetermined) with a specific RAT, and / or may change over time, for example due to changes in radio conditions, mobility, and / or user behavior. The duty cycle may apply to any power level described herein. For example, when transmission is limited to a reserved level (e.g., P reserve ), that particular radio may transmit at a higher peak transmit power level depending on the duty cycle where the average level corresponds to the reserved level.

[0064] For the purpose of verifying the RF exposure compliance of a wireless device, the wireless device may undergo certain RF exposure tests, wherein the maximum RF exposure levels (e.g., SAR and / or PD) are measured in various scenarios including various frequency bands, RF exposure scenarios, and RATs (e.g., 4G, 5G NR, IEEE 802.11, and / or Bluetooth). Here, the maximum RF exposure level in a single radio transmission scenario may be measured when the wireless device is transmitting at a worst-case power level P.limit The measurement is performed with the wireless device uncertainty added. For example, the maximum RF exposure level of the wireless device can be measured on certain LTE and / or 5G NR bands in various RF exposure scenarios including head exposure, body exposure, and / or hotspot exposure.

[0065] Figure 5 is a table illustrating example maximum RF exposure levels measured for a particular wireless device. In this example, the wireless device may exhibit peak RF exposure in certain LTE bands and NR bands for corresponding exposure scenarios. The wireless device may also exhibit RF exposure levels that meet RF exposure compliance limits (e.g., 1.6 W / kg) when transmitting simultaneously over multiple radios.

[0066] A multi-mode / multi-band wireless device 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, a wireless device can limit the maximum transmit power for both frequency bands below 6 GHz and frequency bands above 6 GHz.

[0067] In some cases, the wireless device may evaluate the RF exposure within a given time window in real time to determine the maximum allowed transmit power (e.g., P) for a given time interval based on past transmission history. max ) to ensure that the maximum time-averaged transmit power (e.g., P limit ). In some aspects, the wireless device may be configured to transmit a signal according to P in a single radio transmission scenario. limit In some cases, the wireless device may use a maximum time-averaged transmit power level (e.g., P limit ) to ensure compliance with RF exposure compliance limits, where wireless devices may only allow less than or equal to P limit The transmit power (or specified RF exposure design target level) is determined without considering the actual time-averaged exposure. The lookup table based solution and the time-averaged solution can perform similarly in maximizing the transmit power for a single radio transmit scenario (e.g., where only a single radio is transmitting). Note that here, due to device uncertainty, mass-produced wireless devices have a transmit power of 1 / 400 MHz and a transmit power of 1 / 400 MHz. limit Transmit power levels within plus or minus (+ / -) device uncertainty. RF exposure levels in single radio transmit scenarios for mass-produced wireless devices are within the RF exposure design targets plus or minus (+ / -) device uncertainty. Figure 5The maximum measured RF exposure level close to the RF exposure design target plus the equipment measurement uncertainty is depicted.

[0068] Figure 5 The exposure values ​​depicted are when the wireless device is operating at P limit The worst-case SAR value obtained when transmitting plus the device uncertainty. On the production line, wireless devices can be limit Subtract the uncertainty to P limit plus uncertainty anywhere in between operating at its maximum time-averaged power. Manufacturers report, for example, P limit The worst-case exposure value for a device operating at 1.6 W / kg plus uncertainty. For example, assume that the RF exposure compliance limit is equal to 1.6 W / kg and the device uncertainty is equal to 1 decibel (dB), which is approximately 25%. In order to comply with the RF exposure limit, the RF design target level can be at most 75% of the RF exposure limit (e.g., 1.6*(100%-25%)=1.2 W / kg). In a single-radio case, the wireless device can operate at an RF design target level of 1.0 W / kg, so that the worst-case device produced will have a SAR equal to 1.25 W / kg (e.g., 1.0 W / kg*125%). In a multi-radio case, the wireless device can ensure that the total RF exposure from the active radios is less than or equal to the RF exposure design target (e.g., 1.0 W / kg), where the uncertainty can be between + / - 25% of this level, thereby providing, for example, a worst-case exposure of 1.25 W / kg. In a lookup table approach, the wireless device can operate at a worst-case exposure of 1.2 W / kg in a single-radio case. In the two radio example, instead of reducing each radio to 50%, the lookup table could reduce each radio to some value above 50% as long as the worst case total exposure does not exceed the 1.6 W / kg compliance limit after accounting for the 1 dB (25%) device uncertainty.

[0069] In a multi-radio transmission scenario (e.g., where multiple radios transmit simultaneously or in the same time interval associated with the time averaging time window of the RF exposure limit), the lookup table based solution may operate so that the maximum total exposure from the active radios is close to the RF exposure compliance limit. In the same multi-radio transmission scenario, the time averaging solution may operate so that the maximum total time average exposure from the active radios is less than or equal to the specified RF exposure design target plus device uncertainty, which may be much lower than the RF exposure compliance limit, for example, due to the wireless device's reliance on, for example, Figure 5 In other words, the lookup table based solution may enable the wireless device to transmit at a higher total power level than the time-averaged solution in the multi-radio transmission scenario. For example, the time-averaged solution may result in Figure 5 The maximum total time-averaged exposure is operated at the single-radio exposure level depicted in (e.g., 1.03, 1.15, or 1.25 W / kg), while the lookup table based solution can result in the maximum total exposure being operated at the multi-radio exposure level (e.g., 1.55, 1.57, or 1.59 W / kg).

[0070] Example multi-radio transmission adjustment for time-averaged RF exposure

[0071] Various aspects of the present disclosure provide apparatus and methods for adjusting transmit power in time-averaged RF exposure operations in multi-radio transmission scenarios. In some cases, a wireless device may adjust a maximum time-averaged power level (e.g., P) based on certain scaling information. limit ), as further described herein. For example, the scaling information may indicate an amount to increase transmit power in a multi-radio transmit scenario relative to a single-radio transmit scenario, as further described herein. In some cases, the wireless device may adjust past transmit power history and / or maximum allowed transmit power based on the scaling information, as further described herein. In a multi-radio transmit scenario, the scaling information may enable the wireless device to operate at a time-averaged RF exposure level that is close to an RF exposure compliance limit.

[0072] The apparatus and methods for transmit power adjustment described herein can facilitate improved wireless communication performance (e.g., lower latency, higher throughput, and / or greater transmit range). For example, transmit power adjustment can allow a wireless device to transmit at a transmit power close to or at a time-averaged RF exposure compliance limit in a multi-radio transmission scenario.

[0073] In some aspects, the wireless device may use scaling information to scale the transmit power in the time-averaged RF exposure operation of a multi-radio transmission scenario. The scaling information may indicate a relationship between the multi-radio exposure level and the single-radio exposure level, such as Figure 5 The scaling information may include a scaling factor that is a ratio of the multi-radio exposure level to the single-radio exposure level. The scaling factor may allow the wireless device to allocate an increased level of transmit power to the multi-radio transmission scenario while meeting the RF exposure compliance limits. The scaling factor may be determined according to the following expression:

[0074]

[0075] Exposure multi is the maximum RF exposure level exhibited (or estimated) for the multi-radio transmission scenario, and exposure single is the maximum RF exposure level exhibited (or estimated) for a single radio transmission scenario. singleMay correspond to a measured (or estimated or predetermined) RF exposure level plus an uncertainty level (e.g., +25%). The uncertainty may take into account the uncertainty of the transmit automatic gain control error (e.g., the error or uncertainty of the transmit power reported for a specific time interval associated with the time-averaged RF exposure limit) and / or the device-to-device variation associated with manufacturing wireless devices in mass-produced quantities. For example, a representative wireless device may exhibit RF exposure around a specific RF exposure design target, and 95% of the same mass-produced wireless devices may be within the range of the RF exposure design target plus or minus (+ / -) the device uncertainty, and the worst-case wireless device may be around the RF exposure design target plus the device uncertainty. The exposure levels in the scaling factors may correspond to the same RF exposure scenario, such as head exposure, body exposure, and / or hot spot exposure. The exposure levels in the scaling factors may be the same type of exposure metric, such as SAR or PD. For example, the scaling information may be applied to time-averaged RF exposure compliance in sub-6 GHz bands and / or mmWave bands. It should be understood that the wireless device may apply the scaling information described herein to various time-averaged RF exposure design targets, such as a time-averaged SAR design target or a time-averaged PD design target. In some cases, the scaling factor may be determined as the lowest (minimum) value of the ratio of the multi-radio exposure level to the single-radio exposure level for the corresponding exposure scenario (e.g., based on Figure 5 The exposure levels and corresponding exposure scenarios depicted in , scaling_factor = min{1.55 / 1.03,1.57 / 1.15,1.59 / 1.25} = 1.27).

[0076] In some cases, the wireless device may be configured with various scaling factors corresponding to different transmission scenarios, where the transmission scenario may depend on the RAT, frequency band, antenna, antenna group, radio, RF exposure scenario, or any combination thereof. For example, the wireless device may have a first scaling factor corresponding to head exposure and a second scaling factor corresponding to hotspot exposure. As an example, the wireless device may have a first scaling corresponding to a first NR band set and a second scaling factor corresponding to a second NR band set. It should be understood that other conditions and / or criteria may be used to define transmission scenarios for various configured scaling factors in addition to or instead of those conditions and / or criteria described herein.

[0077] A scaling factor from among multiple scaling factors may be applied depending on the multi-radio transmission scenario. For example, multiple scaling factors may be stored on the device for each single radio supported by the wireless device. A specific scaling factor may be determined for a given multi-radio transmission scenario as a factor associated with at least one of the radios of the corresponding scenario (e.g., for a given set of active single transmission radios and RF exposure scenario). For example, the scaling factor may be determined as the lowest (minimum) factor among the factors associated with the radio of the current multi-radio transmission (e.g., for the current RF exposure scenario, min{scaling_factor(i=1 to N radios that are part of the current multi-radio transmission)}). The wireless device may apply the determined scaling factor to a specific multi-radio transmission scenario, as further described herein.

[0078] In certain aspects, the scaling factor may be applied to P in a multi-radio transmission scenario. limit To obtain a total time-averaged RF exposure close to the compliance limit, the wireless device may use a scaling factor to adjust P limit For example, the wireless device may use a scaling factor to increase P limit In a single radio transmission scenario, the wireless device may prohibit the use of the scaling factor or apply a scaling factor equal to one.

[0079] Figure 6 illustrates example (normalized) transmit power versus time relative to the maximum time-averaged transmit power level (P limit ) of the graph 600, where P limit The graph 600 depicts P across a time window (T) associated with a time-averaged RF exposure level. limit In this example, the wireless device may determine the number of times P is satisfied in the time window (T). limit The maximum allowed transmission power 602 (P max ). The maximum allowed transmission power is 602 (P max ) may be the maximum transmit power level that a wireless device may use within time interval 604 that complies with the time-averaged RF exposure compliance limit.

[0080] The wireless device may determine the maximum allowed transmit power 602 such that the time average transmit power of the past transmit power 606 and the maximum allowed transmit power 602 satisfies a scaled version of the maximum time average transmit power level (eg, P limit_scaled In a multi-radio transmission scenario, the wireless device may use scaling information such as a scaling factor to scale the maximum time-averaged transmit power level (P limitFor example, the wireless device may determine the scaled version of the maximum time-averaged transmit power level as the product of the maximum time-averaged transmit power level and the scaling factor. The wireless device may determine the scaled version of the maximum time-averaged transmit power level based on the scaled version of the maximum time-averaged transmit power level (P limit_scaled ) to assess time-averaged RF exposure compliance. A scaled version of the maximum time-averaged transmit power level may allow the wireless device to transmit at a higher transmit power in a multi-radio transmission scenario. limit and P limit_scaled If the wireless device switches between single-radio and multi-radio transmission scenarios, it may be difficult to perform a time-averaged evaluation of the transmit power. limit_scaled If the wireless device is switched to a single radio transmission scenario, the wireless device cannot guarantee that the average transmission power over time is less than P limit To this end, in some aspects, the wireless device may be based on the use of, for example, P limit and / or P limit_scaled The normalized transmit power is used to evaluate the time-averaged RF exposure compliance, such that the normalized time-averaged transmit power over the time window T is less than or equal to one, regardless of whether it is a single-radio transmit scenario or a multi-radio transmit scenario, thereby making the time-averaged evaluation smooth during the transition between the single-radio transmit scenario and the multi-radio transmit scenario. To further elaborate, the normalized time-averaged transmit power level of one (corresponding to P limit ) is equal to the maximum time-averaged exposure of the RF exposure design target for a representative wireless device, and the worst-case RF exposure for a mass-produced wireless device is the RF exposure design target plus device uncertainty. Similarly, the normalized time-averaged transmit power level one (corresponding to P limit_scaled ) is equal to the maximum time-averaged exposure of a representative wireless device “scaling factor * RF exposure design target”, and the worst-case RF exposure for a mass-produced wireless device is “scaling factor * (RF exposure design target plus device uncertainty)”.

[0081] For certain aspects, for a given time-averaged operation based on a normalized transmit power history (or normalized exposure relative to an RF exposure design target), a scaling factor may be applied to past transmit power and / or a maximum allowed transmit power in a multi-radio transmit scenario. The wireless device may use the scaling factor to adjust past transmit power and / or the maximum allowed transmit power in a time window associated with a time-averaged RF exposure limit. For example, the scaling factor may be used to scale down past transmit power, and the scaling factor may be used to scale up the maximum allowed transmit power.

[0082] Figure 7 is a flow diagram illustrating example operations 700 for ensuring compliance with time-averaged RF exposure compliance limits. Operations 700 may be performed, for example, by a wireless device (e.g., UE 120a) and / or an RF transceiver circuit (e.g., RF transceiver circuit 300). Figure 8 Operations 700 are described, which illustrate example (normalized) transmit power versus time relative to a maximum time-averaged transmit power level (P limit ) is a graph 800 showing a graph of reported transmit power (eg, past transmit power 806 belonging to a compliance time window) and a maximum allowed transmit power (P max ) using the scaling information described in this article (in Figure 7 is scaled by (referred to as multiTx_singleTx_factor in ).

[0083] Operation 700 may optionally begin at block 702, where the wireless device may obtain a transmit power for a particular time interval (e.g., a second time interval 808) in a time window (T) associated with a time-averaged RF exposure. For example, the transmit power may be obtained from a transmit automatic gain control (TxAGC) module at layer 1 (L1) of a protocol stack. For example, L1 may include a physical radio layer (PHY). In certain aspects, a controller 336 of the RF transceiver circuit 300 may obtain (or access) the transmit power for the particular time interval. For example, the controller 336 may include a TxAGC module and track the transmit power output by the transmit path over time. The transmit power report of the past transmit power (e.g., the past transmit power 806) may represent the actual transmit power within the expected device uncertainty.

[0084] At block 704, the wireless device may determine a normalized power report of past transmit power (e.g., past transmit power 806). The normalized power report for a particular time interval (e.g., second time interval 808) may be a report using P limit The normalized power report may be equal to the average transmit power over time during the second time interval 808 divided by P. limit (For example, normalized power report = Tx power report / P limit ), where the transmit power associated with the second time interval 808 is averaged over the second time interval 808. Such normalized power reports may be calculated and tracked for multiple time intervals belonging to the past compliance time window (T), e.g., corresponding to the past transmit power 806. The wireless device may determine a sum of the normalized power reports with the past transmit power 806.

[0085] At block 706, the wireless device may adjust the normalized power report based on scaling information, such as a scaling factor (in Figure 7 810). The wireless device may scale down the normalized power report by the scaling factor. For example, the scaled version of the normalized power report 810 may be equal to the normalized power report divided by the scaling factor. In a single radio transmission scenario, the wireless device may prohibit the use of the scaling factor, or the wireless device may apply a scaling factor equal to one.

[0086] At box 708, the wireless device may perform a time averaging operation based on the scaled version of the normalized power report. The wireless device may determine the normalized exposure margin allowed for the next time interval (e.g., the first time interval 804) in the time window (T) so that the time average of the scaled version of the normalized power report and the exposure margin for the next time interval meet the normalized scaled RF exposure design target. In some aspects, the exposure margin may be the maximum RF exposure that the wireless device can produce and meet the normalized scaled RF exposure design target. The normalized exposure margin may be the exposure percentage remaining relative to the normalized power report and the scaled RF exposure design target. For example, when the time average of the scaled version of the normalized power report and the exposure margin for the next time interval is less than or equal to one (e.g., the normalized scaled RF exposure design target), the normalized scaled RF exposure design target may be met.

[0087] At block 710, the wireless device may determine a maximum allowed transmit power (P max For example, the maximum allowed transmit power (P max ) can be equal to the normalized exposure margin and P limit The product of .

[0088] At block 712, the wireless device may adjust the maximum allowed transmit power based on scaling information, such as a scaling factor (in Figure 7 The wireless device may scale the maximum allowed transmit power by the scaling factor. For example, a scaled version of the maximum allowed transmit power (P max_scaled ) may be equal to the product of the maximum allowed transmit power and the scaling factor. In a single radio transmission scenario, the wireless device may prohibit the use of the scaling factor, or the wireless device may apply a scaling factor equal to one. Figure 8 , the wireless device may use a scaled version 802 of the maximum allowed transmit power as the maximum allowed transmit power for the first time interval 804 .

[0089] At block 714, the wireless device may provide a scaled version of the maximum allowed transmit power 802 to the transceiver circuitry (e.g., the RF transceiver circuitry 300). For example, the TxAGC module may obtain the scaled version of the maximum allowed transmit power 802 as digital RF information (e.g., a particular gain index associated with the output power of the transmit path 302), and the TxAGC module may control the gain applied to the circuits in the transmit path (e.g., adjust the gain at the BBF, mixer, PA, etc.) to output a signal (e.g., an analog RF signal) at the transmit power associated with the digital RF information. The TxAGC module may set the transmit power to a particular level, which may depend on any of a variety of transmit power controls, such as a (scaled) maximum allowed transmit power for RF exposure compliance, RF interference control (e.g., via base station control in closed-loop power control communications), receiver saturation control, RF transmit control (e.g., P CMAX ), thermal control, etc.

[0090] In certain aspects, the wireless device may divide the reservation level among multiple radios in a multi-radio transmission scenario (eg, P in a single radio scenario). reserve / P limit = P in multi-radio transmission scenario reserve1 / P limit1 +P reserve2 / P limit2 +P reserve3 / P limit3 +…P reserve_i / P limit_i ) to maintain compliance with the time-averaged RF exposure limits. For example, when a scaled version of the radio's allowed exposure margin exceeds a base reservation level (e.g., a base reservation level corresponding to a minimum reservation level that allows the radio to maintain communications with a base station or access point under current network conditions), reserve ) and / or in the case where the scaled version of the allowed exposure margin of a radio is below the base reservation level, the wireless device may adjust the exposure margin and / or reservation of certain radios. In some cases, scaling the maximum allowed transmit power may allow uneven application of scaling factors across multiple radios to meet the minimum transmit level (e.g., base P) of each radio. reserve ), thereby maintaining radio links for as many radios as possible. In other words, scaling the maximum allowed transmit power may result in the allowed exposure margin of a radio exceeding or not meeting the basic reservation of the corresponding radio. Figure 4C As described above, the time-averaged solution allows the radio to be above P for a given duration. limit The transmission is performed and the transmission power is set to be lower than P for a duration. limit (For example, P reserve), so that the time average power in the time window is less than or equal to P limit . In the limit In terms of normalization, the wireless device may determine the maximum normalized exposure level (P max / P limit ), and determine the normalized reservation level (P reserve / P limit ).

[0091] In a multi-radio transmission scenario, each radio may operate at a different normalized reservation level (e.g., P reserve1 / P limit1 , P reserve2 / P limit2 When the total time average exposure meets the RF exposure limit, in power consuming scenarios (e.g., when the wireless device transmits at the edge of the cell), the reservation levels of all radios may not be met while maintaining compliance with the time average RF exposure compliance limit. In such a scenario, the wireless device may ensure that each radio obtains at least its corresponding base reservation level, and may then apply a scaling factor to the transmit power of the radio.

[0092] As an example, the wireless device may determine an allowed exposure margin level for each radio for future transmissions (e.g., the first time interval 804) while maintaining time-averaged RF exposure compliance. After applying the scaling factor, the wireless device may determine a scaled version of the allowed exposure margin as follows: normalized exposure level of radio(i) = allowed.exposure(i) * scaling_factor. In some cases, some radios may be assigned an exposure margin that exceeds a base reservation level, and some radios may be assigned an exposure margin that is lower than the base reservation level to maintain a communication link with a receiving entity (e.g., a base station or access point). If any of the radios is assigned an exposure margin that is less than a given reservation level, the wireless device may take the excess margin from the radio that has obtained a margin greater than the base reservation level and redistribute the excess margin to radios that can use the additional exposure margin (e.g., radios that have been assigned a margin that is less than the base reservation level). The wireless device may scale the readjusted exposure margin by a scaling factor (e.g., allowed.exp(i) * scaling_factor).

[0093] Example operations for determining excess margin among active radios and redistributing this excess margin to certain radios are provided below as pseudo code:

[0094]

[0095]

[0096] Fig. 9 9 is a flow diagram illustrating example operations 900 for ensuring compliance with RF exposure limits, where certain margins and / or reservations may be adjusted as described herein. Operations 900 may be the same as operations 700, except for blocks 910 and 912. Operations 900 may be performed, for example, by a wireless device (e.g., UE 120a) and / or an RF transceiver circuit (e.g., RF transceiver circuit 300).

[0097] At block 910, the wireless device may perform operations to redistribute the scaled exposure margin to certain radios. For example, at STEP 1, the wireless device may determine excess margin among radios transmitting in a multi-radio transmission scenario, where the excess margin of a given radio is equal to the difference between a scaled version of the allowed exposure margin and a base reserve level associated with the radio (e.g., allowed.exp(i)*scaling_factor–base reserve(i)). At STEP 2, the wireless device may redistribute the excess margin to one or more radios that are assigned an exposure margin that is less than the base reserve level. At STEP 3, the wireless device may scale the readjusted exposure margin by the scaling factor.

[0098] At block 912, the wireless device may determine a maximum allowed transmit power (P max ).

[0099] Although Figures 6 to 9 The examples depicted in are described herein with respect to determining the scaled transmit power of a particular radio for ease of understanding, but aspects of the present disclosure may be applied to determining the scaled transmit power of each of the radios used in a multi-radio transmission scenario.

[0100] 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 wireless device (e.g., UE 120a in wireless communication network 100). Operations 1000 may be implemented as a processor (e.g., Figure 2 In addition, the signal transmission and / or reception performed by the wireless device 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 wireless device may be achieved by obtaining and / or outputting signals via a bus interface of one or more processors (eg, controller / processor 280).

[0101] Operation 1000 may optionally begin at block 1002, where the wireless device may obtain scaling information indicating a relationship between a first RF exposure associated with a plurality of first radios and a second RF exposure associated with a (single) second radio or a single radio transmission scenario. For example, a memory may store the scaling information, and the wireless device may obtain (or access) the scaling information from the memory (such as memory 282 and / or memory 338). The scaling information may include a ratio of the first RF exposure to the second RF exposure, for example, as described herein with respect to the scaling factor in expression (1). The first RF exposure may correspond to a first exposure level exhibited (or estimated) when the plurality of first radios transmit simultaneously or in the same time interval associated with a time-averaged time window of a time-averaged RF exposure limit (e.g., a multi-radio transmission scenario), and the second RF exposure may correspond to a second exposure level exhibited (or estimated) when only the second radio transmits (e.g., a single radio transmission scenario).

[0102] In some aspects, multiple first radios may include a second radio. For example, the first radio may include an NR band and an IEEE 802.11 channel, and the second radio may include an NR band or an IEEE 802.11 channel. In some cases, the second RF exposure of the second radio may represent the exposure presented (or estimated) by a single radio transmission scenario. For example, the second RF exposure may include an average, median, maximum, or minimum exposure level associated with each exposure level in the exposure level of the first radio, wherein the average, median, maximum, or minimum exposure level may represent a single radio transmission scenario associated with the first radio. It should be understood that the average, median, maximum, or minimum value is merely an example of selecting an exposure level in multiple radios, which exposure level represents the exposure presented (or estimated) by a single radio transmission scenario, and other components for determining the second RF exposure may be used.

[0103] At block 1004, the wireless device may determine one or more transmit powers associated with the plurality of radios based at least in part on the scaling information. The wireless device may adjust various parameters associated with the time-averaged RF exposure based on the scaling information, for example, as described herein with respect to Figures 6 to 9 described.

[0104] At block 1008, the wireless device may use multiple radios to transmit signals at one or more transmit powers determined at least in part based on the time-averaged RF exposure limit and the scaling information. The wireless device may use the radios to transmit multiple signals in a multi-radio transmission scenario (e.g., in the same transmission opportunity). For example, when the wireless device transmits simultaneously via the corresponding cells or transmits in the same time interval (e.g., time interval 604, 804), the wireless device may use the radios to transmit signals in a carrier aggregation scenario or a dual connectivity scenario in NR. When the wireless device transmits signals in NR frequency bands and IEEE 802.11 channels simultaneously or transmits these signals in the same time interval (e.g., time interval 604, 804), the wireless device may use the radios to transmit multiple signals.

[0105] In some cases, to determine the transmit power, the wireless device may adjust the maximum time-averaged power level (P limit ), for example, as described in this article on Figure 6 The wireless device may adjust the maximum time-averaged power level (P) corresponding to the time-averaged RF exposure compliance limit based at least in part on the scaling information. limit ) (e.g., after subtracting device uncertainty). The wireless device may determine a transmit power based at least in part on the adjusted maximum time-averaged power level. To adjust the maximum time-averaged power level, the wireless device may scale the maximum time-averaged power level by a ratio of the first RF exposure to the second RF exposure in the scaling information. To determine the transmit power, the wireless device may determine the transmit power in a time window (T) associated with the RF exposure compliance limit such that one or more transmit powers in the time window and a time average of past transmit powers satisfy the adjusted maximum time-averaged power level. For example, the wireless device may determine a maximum allowed transmit power (e.g., maximum allowed transmit power 602) such that past transmit powers (e.g., past transmit power 606) and a time average transmit power of the maximum allowed transmit power satisfy a scaled version of the maximum time-averaged transmit power level (e.g., P limit_scaled ).

[0106] In some cases, to determine the transmit power, the wireless device may adjust the normalized power report and / or the maximum allowed transmit power, for example, as described herein with respect to Figure 7 and Figure 8The wireless device may adjust a normalized power report and a maximum allowed transmit power in a time window associated with a time average RF exposure compliance limit based on the scaling information. The wireless device may determine the transmit power based at least in part on the adjusted normalized power report (e.g., a scaled version of the normalized power report) and the adjusted maximum allowed transmit power (e.g., a scaled version of the maximum allowed transmit power). To adjust the normalized power report, the wireless device may scale the normalized power report by a first ratio of the second RF exposure to the first RF exposure in the scaling information. To adjust the maximum allowed transmit power, the wireless device may scale the maximum allowed transmit power by a second ratio of the first RF exposure to the second RF exposure in the scaling information.

[0107] In some aspects, the wireless device may adjust exposure margins and / or reservations for certain radios, for example, as described herein with respect to Fig. 9 The wireless device may determine an allowed exposure margin for each of the multiple radios based at least in part on the scaling information (e.g., normalized exposure level of radio(i)=allowed.exposure(i)*scaling_factor). The wireless device may determine excess margin among the multiple radios if the allowed exposure margin is greater than or equal to a first threshold (e.g., a base reservation associated with the corresponding radio). The wireless device may distribute (e.g., reallocate) the excess margin among the multiple radios if the allowed exposure margin is less than or equal to a second threshold (e.g., a base reservation associated with the corresponding radio).

[0108] For certain aspects, the wireless device may be configured with situation-specific scaling factors, and the wireless device may apply a given scaling factor corresponding to a specific situation or scenario. The scaling information may include a plurality of factors (e.g., scaling factors), wherein each of the factors may include a ratio of a first RF exposure to a second RF exposure for a different one of a plurality of transmission scenarios.

[0109] In some cases, the scaling information may include a first factor and a second factor. The first factor may include a first ratio of a first RF exposure to a second RF exposure corresponding to a first transmission scenario, and the second factor may include a second ratio of a first RF exposure to a second RF exposure corresponding to a second transmission scenario different from the first transmission scenario. For example, the first transmission scenario may use a different radio from the second transmission scenario. The wireless device may determine one or more transmission powers based at least in part on the first factor when the first transmission scenario occurs (e.g., in response to the first transmission scenario occurring or being detected to occur in a future time interval (such as time intervals 604, 804)), and the wireless device may determine one or more transmission powers based at least in part on the second factor when the second transmission scenario occurs (e.g., in response to the second transmission scenario occurring or being detected to occur in a future time interval (such as time intervals 604, 804)). The first transmission scenario may differ from the second transmission scenario based at least in part on: RAT (e.g., NR, IEEE 802.11, or Bluetooth), frequency band (e.g., different NR bands), antenna (e.g., different antennas), antenna groups (e.g., different antenna groups), radio, RF exposure scenario (e.g., head exposure, limb exposure, body exposure, or hotspot exposure), or a combination thereof.

[0110] although Figures 1 to 10 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, a UE or other wireless device may communicate with a device other than a network entity (e.g., another UE) or with another device in a user's home that is not a network entity.

[0111] It will be appreciated that the transmit power adjustments described herein may achieve desired wireless communication performance, such as reduced latency, increased uplink data rates, and / or improved transmit range (eg, improved uplink connectivity at a cell edge).

[0112] Example Communication Device

[0113] Fig.11 Examples include operations that may be configured to perform the techniques disclosed herein (such as Fig.101100 (e.g., UE 120) includes various components (e.g., corresponding to means plus function components) of the communication device 1100 (e.g., the operations illustrated in the figure). The communication device 1100 includes a processing system 1102 that can be coupled to a transceiver 1108 (e.g., a transmitter and / or a receiver). The transceiver 1108 is configured to send and receive signals for the communication device 1100 via an antenna 1110, such as various signals as described herein. The processing system 1102 can be configured to perform processing functions of the communication device 1100, including processing signals received and / or to be transmitted by the communication device 1100.

[0114] The processing system 1102 includes a processor 1104 (e.g., one or more processors) coupled to a computer-readable medium / memory 1112 via a bus 1106. In some aspects, the computer-readable medium / memory 1112 is configured to store instructions that, when executed by the processor 1104, cause the communication device 1100 to execute Fig.10 The illustrated operations 1000 or instructions (e.g., computer executable code) for performing other operations discussed herein for providing various techniques for RF exposure that complies with scaled transmit power. In some aspects, the computer readable medium / memory 1112 stores code 1114 for obtaining, code 1116 for transmitting (or outputting), code 1118 for adjusting, code 1120 for determining, or any combination thereof.

[0115] In some aspects, the processing system 1102 has circuitry 1122 configured to implement code stored in the computer readable medium / memory 1112. In some aspects, the circuitry 1122 is coupled to the processor 1104 and / or the computer readable medium / memory 1112 via the bus 1106.

[0116] For example, the circuit 1122 includes a circuit 1124 for obtaining, a circuit 1126 for sending (or outputting), a circuit 1128 for adjusting, and / or a circuit 1130 for determining, or any combination thereof.

[0117] In some examples, the means for transmitting (or the means for outputting for transmitting) may include: Figure 2 The transceiver 254 and / or antenna 252 and / or Fig.11 The transceiver 1108 and antenna 1110 of the communication device 1100.

[0118] In some cases, a device may not actually send, for example, signals and / or data, but may have an interface (components for outputting) signals and / or data for transmission. For example, a processor may output signals and / or data to a radio frequency (RF) front end via a bus interface for transmission. Similarly, a device may not actually receive signals and / or data, but may have an interface (components for obtaining) for obtaining signals and / or data received from another device. For example, a processor may obtain (or receive) signals and / or data from an RF front end via a bus interface for reception. In various aspects, the RF front end may include various components, including transmit and receive processors, transmit and receive MIMO processors, modulators, demodulators, etc., such as Figure 2 as depicted in the example.

[0119] In some examples, the means for obtaining, the means for adjusting, and / or the means for determining may include various processing system components, such as: Fig.11 The processor 1104, or Figure 2 Aspects of the UE 120 are depicted, including a receive processor 258 , a transmit processor 264 , a TX MIMO processor 266 , and / or a controller / processor 280 .

[0120] Example aspects

[0121] Specific implementation examples are described in the following numbered clauses:

[0122] Aspect 1: A method for wireless communication by a wireless device, the method comprising: obtaining scaling information indicating a relationship between a first radio frequency (RF) exposure associated with a plurality of first radios and a second RF exposure associated with a second radio; and transmitting signals using the plurality of radios at one or more transmit powers determined at least in part based on a time-averaged RF exposure limit and the scaling information.

[0123] Aspect 2: The method according to aspect 1, wherein the scaling information includes a ratio of the first RF exposure to the second RF exposure.

[0124] Aspect 3: A method according to aspect 1 or 2, wherein: the first RF exposure corresponds to a first exposure level exhibited when the multiple first radios transmit simultaneously; and the second RF exposure corresponds to a second exposure level exhibited when only the second radio transmits.

[0125] Aspect 4: According to the method described in any one of Aspects 1 to 3, the method also includes: adjusting the maximum time-averaged power level corresponding to the time-averaged RF exposure limit based at least in part on the scaling information; and determining the one or more transmit powers based at least in part on the adjusted maximum time-averaged power level.

[0126] Aspect 5: The method of aspect 4, wherein adjusting the maximum time-averaged power level comprises scaling the maximum time-averaged power level according to a ratio of the first RF exposure to the second RF exposure in the scaling information.

[0127] Aspect 6: A method according to Aspect 4 or 5, wherein determining the one or more transmit powers includes determining the one or more transmit powers in a time window associated with the time-averaged RF exposure limit so that the one or more transmit powers in the time window and the time average of past transmit powers satisfy the adjusted maximum time-averaged power level.

[0128] Aspect 7: According to the method described in any one of Aspects 1 to 6, the method also includes: adjusting the normalized power report and the maximum allowed transmit power in the time window associated with the time-averaged RF exposure limit based on the scaling information; and determining the one or more transmit powers based at least in part on the adjusted normalized power report and the adjusted maximum allowed transmit power.

[0129] Aspect 8: A method according to Aspect 7, wherein adjusting the normalized power report and the maximum allowed transmit power includes: scaling the normalized power report according to a first ratio of the second RF exposure to the first RF exposure in the scaling information; and scaling the maximum allowed transmit power according to a second ratio of the first RF exposure to the second RF exposure in the scaling information.

[0130] Aspect 9: According to the method described in any one of Aspects 1 to 9, the method further includes: determining an allowed exposure margin for each of the multiple radios based at least in part on the scaling information; determining an excess margin among the multiple radios when the allowed exposure margin is greater than or equal to a first threshold; and distributing the excess margin among the multiple radios when the allowed exposure margin is less than or equal to a second threshold.

[0131] Aspect 10: A method according to any one of Aspects 1 to 9, wherein: the scaling information includes multiple factors; and each of the factors includes a ratio of the first RF exposure to the second RF exposure for a different transmission scenario among multiple transmission scenarios.

[0132] Aspect 11: A method according to any one of Aspects 1 to 10, wherein: the scaling information includes a first factor and a second factor; the first factor includes a first ratio of the first RF exposure to the second RF exposure corresponding to a first transmission scenario; and the second factor includes a second ratio of the first RF exposure to the second RF exposure corresponding to a second transmission scenario different from the first transmission scenario.

[0133] Aspect 12: According to the method described in Aspect 11, the method also includes: when the first transmission scenario occurs, determining the one or more transmission powers at least partially based on the first factor; and when the second transmission scenario occurs, determining the one or more transmission powers at least partially based on the second factor.

[0134] Aspect 13: The method according to aspect 11 or 12, wherein the first transmission scenario is different from the second transmission scenario based at least in part on: radio access technology, frequency band, antenna, radio, RF exposure scenario, or a combination thereof.

[0135] Aspect 14: A device for wireless communication, the device comprising: a memory; and one or more processors coupled to the memory, the one or more processors being configured to: obtain scaling information indicating a relationship between a first radio frequency (RF) exposure associated with a plurality of first radios and a second RF exposure associated with a second radio; and control the transmission of a signal using the plurality of radios to determine one or more transmit powers based at least in part on a time-averaged RF exposure limit and the scaling information.

[0136] Aspect 15: An apparatus according to Aspect 14, further comprising a transmitter coupled to the one or more processors and configured to transmit the signal using the multiple radios at the one or more transmit powers, wherein the scaling information comprises a ratio of the first RF exposure to the second RF exposure.

[0137] Aspect 16: An apparatus according to Aspect 14 or 15, wherein: the first RF exposure corresponds to a first exposure level exhibited when the multiple first radios transmit simultaneously or in the same time interval; and the second RF exposure corresponds to a second exposure level exhibited when only the second radio transmits.

[0138] Aspect 17: An apparatus according to any one of Aspects 14 to 16, wherein the one or more processors are further configured to: adjust the maximum time-averaged power level corresponding to the time-averaged RF exposure limit based at least in part on the scaling information; and determine the one or more transmit powers based at least in part on the adjusted maximum time-averaged power level.

[0139] Aspect 18: An apparatus according to Aspect 17, wherein to adjust the maximum time-averaged power level, the one or more processors are further configured to scale the maximum time-averaged power level according to a ratio of the first RF exposure to the second RF exposure in the scaling information.

[0140] Aspect 19: An apparatus according to Aspect 17 or 18, wherein in order to determine the one or more transmit powers, the one or more processors are further configured to determine the one or more transmit powers in a time window associated with the time-averaged RF exposure limit so that the time average of the one or more transmit powers in the time window and the past transmit powers satisfies the adjusted maximum time-averaged power level.

[0141] Aspect 20: An apparatus according to any one of Aspects 14 to 19, wherein the one or more processors are further configured to: adjust a normalized power report and a maximum allowed transmit power in a time window associated with the time-averaged RF exposure limit based on the scaling information; and determine the one or more transmit powers based at least in part on the adjusted normalized power report and the adjusted maximum allowed transmit power.

[0142] Aspect 21: An apparatus according to Aspect 20, wherein in order to adjust the normalized power report and the maximum allowed transmit power, the one or more processors are further configured to: scale the normalized power report according to a first ratio of the second RF exposure to the first RF exposure in the scaling information, and scale the maximum allowed transmit power according to a second ratio of the first RF exposure to the second RF exposure in the scaling information.

[0143] Aspect 22: An apparatus according to any one of Aspects 14 to 21, wherein the one or more processors are further configured to: determine an allowed exposure margin for each of the multiple radios based at least in part on the scaling information; determine an excess margin among the multiple radios when the allowed exposure margin is greater than or equal to a first threshold; and distribute the excess margin among the multiple radios when the allowed exposure margin is less than or equal to a second threshold.

[0144] Aspect 23: An apparatus according to any one of Aspects 14 to 22, wherein: the scaling information includes multiple factors; and each of the factors includes a ratio of the first RF exposure to the second RF exposure for a different transmission scenario among multiple transmission scenarios.

[0145] Aspect 24: An apparatus according to any one of Aspects 14 to 23, wherein: the scaling information includes a first factor and a second factor; the first factor includes a first ratio of the first RF exposure to the second RF exposure corresponding to a first transmission scenario; and the second factor includes a second ratio of the first RF exposure to the second RF exposure corresponding to a second transmission scenario different from the first transmission scenario.

[0146] Aspect 25: An apparatus according to Aspect 24, wherein the one or more processors are further configured to: determine the one or more transmission powers based at least in part on the first factor when the first transmission scenario occurs; and determine the one or more transmission powers based at least in part on the second factor when the second transmission scenario occurs.

[0147] Aspect 26: The apparatus according to aspect 24 or 25, wherein the first transmission scenario differs from the second transmission scenario based at least in part on: radio access technology, frequency band, antenna, radio, RF exposure scenario, or a combination thereof.

[0148] Aspect 27: A non-transitory computer-readable medium having instructions stored thereon, the instructions being used to: obtain scaling information indicating a relationship between a first radio frequency (RF) exposure associated with a plurality of first radios and a second RF exposure associated with a second radio; and transmit signals using the plurality of radios at one or more transmit powers determined at least in part based on a time-averaged RF exposure limit and the scaling information.

[0149] Aspect 28: A device 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 processing system to perform a method according to any one of Aspects 1 to 13.

[0150] Aspect 29: An apparatus comprising means for performing the method according to any one of aspects 1 to 13.

[0151] Aspect 30: 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 13.

[0152] Aspect 31: A computer program product embodied on a computer-readable storage medium, the computer program product comprising code for executing the method according to any one of aspects 1 to 13.

[0153] 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.

[0154] 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.

[0155] UE may also be referred to 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 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 vehicle 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 as 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.

[0156] 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.

[0157] 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.

[0158] 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).

[0159] 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.

[0160] 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...".

[0161] 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.

[0162] 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.

[0163] 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.

[0164] 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.

[0165] 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.

[0166] 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.

[0167] 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, which instructions can be executed by one or more processors to perform the operations described herein, such as for performing the operations described herein and in Fig.10 Instructions for the operations illustrated in .

[0168] 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.

[0169] 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, the method comprising: obtaining scaling information indicating a relationship between a first radio frequency (RF) exposure associated with a plurality of first radios and a second RF exposure associated with a second radio; as well as Signals are transmitted using the plurality of radios at one or more transmit powers determined based at least in part on the time average RF exposure limit and the scaling information. 2 . The method of claim 1 , wherein the scaling information comprises a ratio of the first RF exposure to the second RF exposure.

3. The method according to claim 1, wherein: The first RF exposure corresponds to a first exposure level exhibited when the plurality of first radios transmit simultaneously or in a same time interval; and The second RF exposure corresponds to a second exposure level exhibited when only the second radio transmits.

4. The method according to claim 1, further comprising: adjusting a maximum time-averaged power level corresponding to the time-averaged RF exposure limit based at least in part on the scaling information; as well as The one or more transmit powers are determined based at least in part on the adjusted maximum time-averaged power level. 5 . The method of claim 4 , wherein adjusting the maximum time-averaged power level comprises scaling the maximum time-averaged power level by a ratio of the first RF exposure to the second RF exposure in the scaling information.

6. A method according to claim 4, wherein determining the one or more transmit powers includes determining the one or more transmit powers in a time window associated with the time-averaged RF exposure limit so that the one or more transmit powers in the time window and the time average of past transmit powers meet the adjusted maximum time-averaged power level.

7. The method according to claim 1, further comprising: adjusting a normalized power report and a maximum allowed transmit power in a time window associated with the time-averaged RF exposure limit based on the scaling information; as well as The one or more transmit powers are determined based at least in part on the adjusted normalized power report and the adjusted maximum allowed transmit power.

8. The method of claim 7, wherein adjusting the normalized power report and the maximum allowed transmit power comprises: scaling the normalized power report by a first ratio of the second RF exposure to the first RF exposure in the scaling information; as well as The maximum allowed transmit power is scaled according to a second ratio of the first RF exposure to the second RF exposure in the scaling information.

9. The method according to claim 1, further comprising: determining an allowed exposure margin for each of the plurality of radios based at least in part on the scaled information; determining an excess margin among the plurality of radios if the allowed exposure margin is greater than or equal to a first threshold; as well as The excess margin is distributed among the plurality of radios if the allowed exposure margin is less than or equal to a second threshold.

10. The method of claim 1, wherein: The scaling information includes a plurality of factors; and Each of the factors includes a ratio of the first RF exposure to the second RF exposure for a different transmission scenario among a plurality of transmission scenarios.

11. The method according to claim 1, wherein: The scaling information includes a first factor and a second factor; The first factor comprises a first ratio of the first RF exposure to the second RF exposure corresponding to a first transmission scenario; and The second factor includes a second ratio of the first RF exposure to the second RF exposure corresponding to a second transmission scenario different from the first transmission scenario.

12. The method according to claim 11, further comprising: When the first transmission scenario occurs, determining the one or more transmission powers based at least in part on the first factor; as well as When the second transmission scenario occurs, the one or more transmission powers are determined based at least in part on the second factor.

13. The method of claim 11, wherein the first transmission scenario differs from the second transmission scenario based at least in part on: Radio access technology, frequency band, antenna, radio, RF exposure scenarios, or A combination of them.

14. An apparatus for wireless communication, the apparatus comprising: Memory; and one or more processors coupled to the memory, the one or more processors configured to: obtaining scaling information indicating a relationship between a first radio frequency (RF) exposure associated with a plurality of first radios and a second RF exposure associated with a second radio, and The transmission of signals is controlled using the plurality of radios to one or more transmit powers determined based at least in part on the time average RF exposure limit and the scaling information.

15. The apparatus of claim 14, further comprising a transmitter coupled to the one or more processors and configured to transmit the signal at the one or more transmit powers using the multiple radios, wherein the scaling information comprises a ratio of the first RF exposure to the second RF exposure.

16. The device according to claim 14, wherein: The first RF exposure corresponds to a first exposure level exhibited when the plurality of first radios transmit simultaneously or in a same time interval; and The second RF exposure corresponds to a second exposure level exhibited when only the second radio transmits.

17. The apparatus of claim 14, wherein the one or more processors are further configured to: adjusting a maximum time-averaged power level corresponding to the time-averaged RF exposure limit based at least in part on the scaling information, and The one or more transmit powers are determined based at least in part on the adjusted maximum time-averaged power level.

18. The apparatus of claim 17, wherein to adjust the maximum time-averaged power level, the one or more processors are further configured to scale the maximum time-averaged power level according to a ratio of the first RF exposure to the second RF exposure in the scaling information.

19. An apparatus according to claim 17, wherein, in order to determine the one or more transmit powers, the one or more processors are further configured to determine the one or more transmit powers in a time window associated with the time-averaged RF exposure limit so that the one or more transmit powers in the time window and the time average of past transmit powers meet the adjusted maximum time-averaged power level.

20. The apparatus of claim 14, wherein the one or more processors are further configured to: adjusting a normalized power report and a maximum allowed transmit power in a time window associated with the time-averaged RF exposure limit based on the scaling information, and The one or more transmit powers are determined based at least in part on the adjusted normalized power report and the adjusted maximum allowed transmit power.

21. The apparatus of claim 20, wherein to adjust the normalized power report and the maximum allowed transmit power, the one or more processors are further configured to: scaling the normalized power report by a first ratio of the second RF exposure to the first RF exposure in the scaling information, and The maximum allowed transmit power is scaled according to a second ratio of the first RF exposure to the second RF exposure in the scaling information.

22. The apparatus of claim 14, wherein the one or more processors are further configured to: determining an allowed exposure margin for each of the plurality of radios based at least in part on the scaled information, determining an excess margin among the plurality of radios if the allowed exposure margin is greater than or equal to a first threshold, and The excess margin is distributed among the plurality of radios if the allowed exposure margin is less than or equal to a second threshold.

23. The apparatus of claim 14, wherein: The scaling information includes a plurality of factors; and Each of the factors includes a ratio of the first RF exposure to the second RF exposure for a different transmission scenario among a plurality of transmission scenarios.

24. The apparatus of claim 14, wherein: The scaling information includes a first factor and a second factor; The first factor comprises a first ratio of the first RF exposure to the second RF exposure corresponding to a first transmission scenario; and The second factor includes a second ratio of the first RF exposure to the second RF exposure corresponding to a second transmission scenario different from the first transmission scenario.

25. The apparatus of claim 24, wherein the one or more processors are further configured to: determining the one or more transmit powers based at least in part on the first factor when the first transmit scenario occurs, and When the second transmission scenario occurs, the one or more transmission powers are determined based at least in part on the second factor.

26. The apparatus of claim 24, wherein the first transmission scenario differs from the second transmission scenario based at least in part on: Radio access technology, frequency band, antenna, radio, RF exposure scenarios, or A combination of them.

27. A non-transitory computer readable medium having stored thereon instructions for: obtaining scaling information indicating a relationship between a first radio frequency (RF) exposure associated with a plurality of first radios and a second RF exposure associated with a second radio; and Signals are transmitted using the plurality of radios at one or more transmit powers determined based at least in part on the time average RF exposure limit and the scaling information.

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