Radio frequency exposure management for multiple radios

Abstract

Techniques and apparatus for radio frequency (RF) exposure management for multiple radios are described. An example method of wireless communication by a wireless device generally includes determining a first exposure associated with a first radio for a first transmission within a first time interval; determining a first allowable transmit power associated with a second radio for a second time interval based at least in part on the first exposure associated with the first radio; and transmitting a first signal at a first transmission power within the second time interval using the second radio based on the first allowable transmission power.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims priority to U.S. Patent Application No. 18 / 545,751, filed on December 19, 2023, which claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 476,618, filed on December 21, 2022. Both of these applications are hereby incorporated by reference in their entireties for all applicable purposes. Technical Field

[0003] Aspects of the present disclosure relate to wireless communication and, more particularly, to radio frequency (RF) exposure compliance. Background Art

[0004] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcasting, etc. Modern wireless devices such as cellular phones are typically required to meet radio frequency (RF) exposure limits set by certain government and international standards and regulations. To ensure compliance, such devices typically undergo extensive certification processes before being shipped to the market. To ensure that wireless devices comply with RF exposure limits, techniques have been developed that enable wireless devices to evaluate RF exposure from the wireless device and accordingly adjust the transmit power of the wireless device to comply with the RF exposure limits. Summary of the Invention

[0005] The systems, methods, and devices of the present disclosure each have several aspects, no single one of which is solely responsible for its desirable attributes. Without limiting the scope of the present disclosure as expressed by the appended claims, some features will now be briefly discussed. After considering these discussions and particularly after reading the section entitled "Detailed Description," one will understand how the features of the present disclosure provide advantages that include improved wireless communication performance.

[0006] Certain aspects of the subject matter described in the present disclosure may be implemented in a method for wireless communication by a wireless device. The method generally includes: determining a first exposure associated with a first radio for a first transmission during a first time interval; determining a first allowable transmit power associated with a second radio for a second time interval at least in part based on the first exposure associated with the first radio; and transmitting a first signal at a first transmit power using the second radio during the second time interval based on the first allowable transmit power.

[0007] Certain aspects of the subject matter described in this disclosure may be implemented in an apparatus for wireless communication. The apparatus generally includes: one or more memories that collectively store executable instructions; and one or more processors coupled to the one or more memories. The one or more processors are collectively configured to execute the executable instructions to cause the apparatus to: determine a first exposure associated with a first radio used for a first transmission during a first time interval; determine a first allowable transmit power associated with a second radio used for a second time interval at least in part based on the first exposure associated with the first radio; and control the use of the second radio to transmit a first signal at a first transmit power during the second time interval based on the first allowable transmit power.

[0008] 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 determining a first exposure associated with a first radio used for a first transmission during a first time interval. The apparatus also includes means for determining a first allowable transmit power associated with a second radio used for a second time interval at least in part based on the first exposure associated with the first radio. The apparatus also includes means for using the second radio to transmit a first signal at a first transmit power during the second time interval based on the first allowable transmit power.

[0009] Certain aspects of the subject matter described in this disclosure may be implemented in a computer-readable medium. The computer-readable medium has instructions stored thereon that, when executed by an apparatus, cause the apparatus to perform operations. The operations include determining a first exposure associated with a first radio used for a first transmission during a first time interval. The operations also include determining a first allowable transmit power associated with a second radio used for a second time interval at least in part based on the first exposure associated with the first radio. The operations also include using the second radio to transmit a first signal at a first transmit power during the second time interval based on the first allowable transmit power.

[0010] In other aspects, provided is: an apparatus capable of operating, configured to, or otherwise adapted to perform any one or more of the foregoing methods and / or those methods described elsewhere herein; a non-transitory computer-readable medium including instructions that, when executed by a processor of the apparatus, cause the apparatus to perform the foregoing methods and those methods described elsewhere herein; a computer program product embodied on a computer-readable storage medium, the computer-readable storage medium including: code for performing the foregoing methods and those methods described elsewhere herein; and / or an apparatus including components for performing the foregoing methods and those methods described elsewhere herein. By way of example, an apparatus may include a processing system, a device having a processing system, or processing systems cooperating via one or more networks.

[0011] To achieve the foregoing 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 drawings set forth in detail certain illustrative features of the one or more aspects. However, these features are indicative of only some of the various ways in which the principles of the various aspects may be employed. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] To obtain a more particular description of the features briefly summarized above, reference may be made to some aspects illustrated in the accompanying drawings. It is to be noted, however, that the drawings illustrate only certain typical aspects of the present disclosure and are therefore not to be considered limiting of its scope, as the specification may admit other equally effective aspects.

[0013] Figure 1 is a block diagram conceptually illustrating an example wireless communication network.

[0014] Figure 2 is a block diagram conceptually illustrating the design of an example base station (BS) and user equipment (UE).

[0015] Figure 3 is a block diagram of an example radio frequency (RF) transceiver.

[0016] Figure 4A 、 Figure 4B and Figure 4C is a graph illustrating an example of the transmit power over time that complies with the time-averaged RF exposure limit.

[0017] Figure 5 is a diagram of an example processing architecture for distributing energy among multiple radios.

[0018] Figure 6AIs a timing diagram illustrating an example of RF exposure management for a wireless device having two radios according to certain aspects of the present disclosure.

[0019] Figure 6B Is an illustration according to certain aspects of the present disclosure Figure 6A Of the timing diagram of an example of the RF exposure management depicted in, which RF exposure management is performed within a time window (T) associated with a time-averaged RF exposure limit.

[0020] Figure 7A Is a timing diagram illustrating an example of RF exposure management for a wireless device having three radios according to certain aspects of the present disclosure.

[0021] Figure 7B Is an illustration according to certain aspects of the present disclosure Figure 7A Of the timing diagram of an example of the RF exposure management depicted in, which RF exposure management is performed within a time window (T) associated with a time-averaged RF exposure limit.

[0022] Figure 8 Is a flowchart illustrating an example operation for wireless communication by a wireless device according to certain aspects of the present disclosure.

[0023] Figure 9 Illustrates a communication device (e.g., UE) according to certain aspects of the present disclosure that may include various components configured to perform operations of the techniques disclosed herein.

[0024] For ease of understanding, the same reference numerals have been used, where possible, to denote the same elements common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized in other aspects without specific recitation. Detailed Description

[0025] Aspects of the present disclosure provide apparatus, methods, processing systems, and computer-readable media for radio frequency (RF) exposure management of multiple radios.

[0026] In some cases, a wireless device may be equipped with multiple radios for wireless communication, such as Code Division Multiple Access (CDMA), Evolved Universal Terrestrial Radio Access (E-UTRA), 5th Generation New Radio (5G NR), Institute of Electrical and Electronics Engineers (IEEE) 802.11, Bluetooth, non-terrestrial networks, etc. For example, some wireless devices may support multi-mode (e.g., E-UTRA and 5G NR, 5G NR and IEEE 802.11, etc.) and / or multi-band (e.g., sub-6 gigahertz (GHz) band and millimeter wave (mmWave) band) communication via multiple transmit antennas (or radios) for simultaneous or concurrent transmission. To ensure compliance with RF exposure limits, the wireless device may limit the maximum combined instantaneous transmit power for multi-mode / multi-band communication. To account for multi-radio communication, the wireless device may be configured with a per-radio maximum allowable transmit power for each transmit scenario, which includes single-radio scenarios and multi-radio scenarios (e.g., multi-mode / multi-band scenarios), where a transmit scenario may correspond to one or more radios, one or more frequency bands, one or more antennas, and / or one or more exposure scenarios (e.g., head exposure, limb exposure, body exposure, or hotspot exposure) for transmission within a time interval. The wireless device may be configured with a look-up table of maximum allowable transmit powers corresponding to various transmit scenarios, and the wireless device may use a specific value of the maximum allowable transmit power in the look-up table according to the transmit scenario. For a multi-radio scenario, the look-up table may have a pre-limited back-off for each radio in the radios.

[0027] Aspects of the present disclosure provide apparatuses and methods for RF exposure management of multiple radios. A wireless device may sequentially evaluate the RF exposure compliance of each radio such that a combined transmit power determined for each radio within different time intervals in a sequence of time intervals complies with RF exposure limits. For example, for a future time interval, the wireless device may determine the transmit power of a first radio based on the past RF exposure generated by a second radio during a past time interval. The transmit power of the first radio may be the remaining transmit power available for transmission within the future time interval after considering the past RF exposure generated by the second radio. The wireless device may continue to perform such multi-radio exposure evaluations. For example, the wireless device may first determine the RF exposure and corresponding transmit power associated with a first time interval for one radio (e.g., the one radio is a higher-priority radio or a Tier 1 radio), and may use any remaining available RF exposure for another radio (e.g., a lower-priority radio or a Tier 2 radio) within a second time interval after the first time interval. The wireless device may extend the sequential exposure evaluation to any number of radios. For example, a third time interval (which may be the same as or different from the second time interval) may be used for a third radio (e.g., a radio with an even lower priority or a Tier 3 radio), which may use the remaining exposure left over from the combined exposure of the first radio and the second radio.

[0028] The apparatuses and methods for multi-radio RF exposure management described herein may be beneficial for improving wireless communication performance (e.g., improving signal quality at a receiver, reducing latency, increasing throughput, etc.). For example, multi-radio RF exposure management may allow a wireless device to evaluate the RF exposure for each time interval and allocate any remaining exposure to other radios. Multi-radio RF exposure management may allow a wireless device to select a radio with a relatively high priority for preferential allocation of exposure, which may improve the wireless communication performance of a particular radio.

[0029] As used herein, a radio may refer to one or more active frequency bands, transceivers, and / or radio access technologies (RATs) for wireless communication (e.g., code division multiple access (CDMA), long term evolution (LTE), NR, IEEE 802.11, Bluetooth, etc.). For example, for uplink carrier aggregation or dual connectivity in LTE and / or NR, each active component carrier (or serving cell) in the active component carriers (or serving cells) for wireless communication may be considered a separate radio. Similarly, multi-band transmission for IEEE 802.11 communication may be considered separate radios for each frequency band (e.g., 2.4 GHz, 5 GHz, or 6 GHz).

[0030] The following description provides examples of RF exposure compliance in a communication system and is not intended to limit the scope, applicability, or examples set forth in the claims. Changes may be made to the functionality and arrangement of the elements discussed without departing from the scope of the present disclosure. Various examples may omit, substitute, or add various processes or components as appropriate. For example, the methods described may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with respect to some examples may be combined in some other examples. For instance, any number of aspects set forth herein may be used to implement an apparatus or practice a method. Further, the scope of the present disclosure is intended to cover such apparatus or methods practiced using other structures, functionality, or a combination of structures and functionality that supplement or replace various aspects of the present disclosure set forth herein. It should be understood that any aspect of the disclosure herein may be embodied by one or more elements of the claims. The term "exemplary" is used herein to mean "serving as an example, instance, or illustration". Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or having an advantage over other aspects.

[0031] In general, any number of wireless networks may be deployed in a given geographical area. Each wireless network may support a particular radio access technology (RAT) and may operate on one or more frequencies. A RAT may also be referred to as a radio technology, air interface, etc. A frequency may also be referred to as a carrier, subcarrier, frequency channel, tone, subband, etc. Each frequency may support a single RAT in a given geographical area to avoid interference between wireless networks of different RATs, or may support multiple RATs.

[0032] The techniques described herein may be used for various wireless networks and radio technologies. Although aspects may be described herein using terms typically associated with 3G, 4G, and / or New Radio (e.g., 5G NR) wireless technologies, 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 megahertz (MHz) or above), millimeter wave (mmWave) targeting high carrier frequencies (e.g., 24 GHz to 53 GHz or above), massive machine type communication (mMTC) targeting non-backward compatible machine type communication (MTC) technology, and / or mission-critical targeting ultra-reliable low latency communication (URLLC). These services can include latency and reliability specifications. These services can also have different transmission time intervals (TTIs) to meet the 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. Precoded multiple input multiple output (MIMO) transmission can also be supported as multi-layer transmission. Aggregation of multiple cells can be supported.

[0034] Example wireless communication network and device

[0035] Figure 1 An example wireless communication network 100 in which aspects of the present disclosure may be implemented is illustrated. For example, the wireless communication network 100 can be a New Radio (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 second generation (2G) / third generation (3G) network), or a code division multiple access (CDMA) system (e.g., a 2G / 3G network), or can be configured to communicate according to IEEE standards (such as one or more of the 802.11 standards). As Figure 1 shown, according to aspects of the present disclosure, the UE 120a includes an RF exposure manager 122 that ensures RF exposure compliance across multiple radios.

[0036] As Figure 1 illustrated, the wireless communication network 100 can include multiple base stations (BSs) 110a - 110z (each also referred to herein individually as a BS 110, or collectively as BS 110) and other network entities. The BS 110 can provide communication coverage for a specific geographical area (sometimes referred to as a "cell"), which can be stationary or mobile depending on the location of the mobile BS. In some examples, the BS 110 can use any suitable transmission network and 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.). In Figure 1In the example shown, BS 110a, 110b, and 110c can be macro BSs for macro cells 102a, 102b, and 102c, respectively. BS 110x can be a pico BS for pico cell 102x. BS 110y and 110z can be femto BSs for femto cells 102y and 102z, respectively. A BS can support one or more cells.

[0037] BS 110 communicates with UEs 120a - 120y (each also referred to herein individually as UE 120, or collectively as UE 120) in the wireless communication network 100. The UEs 120 (e.g., 120x, 120y, etc.) can be scattered throughout the wireless communication network 100, and each UE 120 can be stationary or mobile. The wireless communication network 100 can also include relay stations (e.g., relay station 110r) (also referred to as relays, etc.), which receive transmissions of data and / or other information from an upstream station (e.g., BS 110a or UE 120r) and forward the transmissions of the data and / or other information to a downstream station (e.g., UE 120 or BS 110), or relay transmissions between UEs 120 to facilitate communication between devices.

[0038] The network controller 130 can communicate with a set of BSs 110 and provide coordination and control for these BSs 110 (e.g., via a backhaul). In some cases, such as in a 5G NR system, the network controller 130 can include a Centralized Unit (CU) and / or a Distributed Unit (DU). In some aspects, the network controller 130 can 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 function, policy control function, authentication server function, unified data management, application function, network exposure function, network repository function, network slice selection function, etc.

[0039] In the present disclosure, the term "beam" can be used in various contexts. A beam can be used to mean a set of gains and / or phases (e.g., precoding weights or in-phase weights) applied to antenna elements in a UE and / or a BS for transmission or reception. The term "beam" can also refer to the antenna or radiation pattern of a signal transmitted when gains and / or phases are applied to the antenna elements. Other references to a beam can include one or more characteristics or parameters associated with an antenna (radiation) pattern, such as angle of arrival (AoA), angle of departure (AoD), gain, phase, directivity, beamwidth, beam direction in terms of azimuth and elevation (relative to a reference plane), peak sidelobe ratio, or an antenna port associated with the antenna (radiation) pattern. The term "beam" can also refer to the associated number and / or configuration of antenna elements (e.g., uniform linear array, uniform rectangular array, or other uniform arrays).

[0040] Figure 2 Example components of BS 110a and UE 120a that can be used to implement aspects of the present disclosure (e.g., Figure 1 of the wireless communication network 100).

[0041] At BS 110a, the transmit processor 220 can receive data from the data source 212 and control information from the controller / processor 240. The control information can be used for physical broadcast channel (PBCH), physical control format indicator channel (PCFICH), physical hybrid automatic repeat request (HARQ) indicator channel (PHICH), physical downlink control channel (PDCCH), group common PDCCH (GC PDCCH), etc. The data can be used for physical downlink shared channel (PDSCH), etc. A medium access control (MAC)-control element (MAC-CE) is a MAC layer communication structure that can be used for the exchange of control commands between wireless nodes. The MAC-CE can be carried in a shared channel (such as PDSCH, physical uplink shared channel (PUSCH), or physical sidelink shared channel (PSSCH)).

[0042] 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 physical broadcast channel demodulation reference signal (DMRS), and a channel state information reference signal (CSI-RS). A transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, control symbols, and / or reference symbols (where applicable) and may provide an output symbol stream to a modulator (MOD) in the transceiver 232a-232t. Each modulator 232a-232t in the transceiver may process its respective output symbol stream (e.g., for orthogonal frequency division multiplexing (OFDM), etc.) to obtain an output sample stream. Each transceiver in the transceiver 232a-232t may further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The downlink signals from the transceiver 232a-232t may be transmitted via antennas 234a-234t, respectively.

[0043] At the UE 120a, antennas 252a-252r may receive downlink (DL) signals from the BS 110a and may provide the received signals to the transceiver 254a-254r, respectively. The transceiver 254a-254r may condition (e.g., filter, amplify, down-convert, and digitize) the respective received signals to obtain input samples. Each demodulator (DEMOD) in the transceiver 232a-232t may further process the input samples (e.g., for OFDM, etc.) to obtain the received symbols. A MIMO detector 256 may obtain the received symbols from all the demodulators in the transceiver 254a-254r, perform MIMO detection (where applicable) on the received symbols, and provide detected symbols. A receive processor 258 may process (e.g., demodulate, de-interleave, and decode) the detected symbols, provide the decoded data for the UE 120a to a data sink 260, and provide the decoded control information to the controller / processor 280.

[0044] On the uplink, at the UE 120a, the transmit processor 264 may receive and process data (e.g., for the Physical Uplink Shared Channel (PUSCH)) from the data source 262, and receive and process control information (e.g., for the Physical Uplink Control Channel (PUCCH)) from the controller / processor 280. The transmit processor 264 may also generate reference symbols for reference signals (e.g., for the Sounding Reference Signal (SRS)). Symbols from the transmit processor 264 may be pre-coded by the TX MIMO processor 266 (if applicable), further processed by a modulator (MOD) in the transceiver 254a - 254r (e.g., for Single Carrier Frequency Division Multiplexing (SC-FDM), etc.), and transmitted to the BS 110a. At the BS 110a, the uplink (UL) signal from the UE 120a may be received by the antenna 234, processed by a demodulator in the transceiver 232a - 232t, detected by the MIMO detector 236 (if applicable), and further processed by the receive processor 238 to obtain the decoded data and control information transmitted by the UE 120a. The receive processor 238 may provide the decoded data to the data sink 239 and the decoded control information to the controller / processor 240.

[0045] The memories 242 and 282 may store data and program codes for the BS 110a and the UE 120a, respectively. The scheduler 244 may schedule the UE for data transmission on the downlink and / or uplink.

[0046] The antenna 252, processors 266, 258, 264, and / or the controller / processor 280 of the UE 120a and / or the antenna 234, processors 220, 230, 238, and / or the controller / processor 240 of the BS 110a may be used to perform the various techniques and methods described herein. As Figure 2 shown, according to aspects described herein, the controller / processor 280 of the UE 120a has an RF exposure manager 281 representing the RF exposure manager 122. Although shown at the controller / processor, other components of the UE 120a and the BS 110a may be used to perform the operations described herein.

[0047] NR can utilize OFDM with a cyclic prefix (CP) on both the uplink and downlink. NR can use time division duplex (TDD) to support half-duplex operation. OFDM and SC-FDM divide the system bandwidth into multiple orthogonal subcarriers, which are also often referred to as tones, frequency bins, 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).

[0048] Although reference Figure 1 and Figure 2 describe the UE 120a as communicating with the BS and / or within the network, the UE 120a can be configured to communicate directly with another UE 120 / directly send to the other UE, or communicate directly with another wireless device / send to the other wireless device without relaying the communication through the network. In some aspects, the BS 110a illustrated and described above in Figure 2 is an example of another UE 120.

[0049] Example RF transceiver

[0050] 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 the antenna 306. When the TX path 302 and the RX path 304 share the antenna 306, these paths can be connected to the antenna via an interface 308, which can include any of various suitable RF devices, such as switches, duplexers, diplexers, multiplexers, etc.

[0051] Receiving an in-phase (I) or quadrature (Q) baseband analog signal from a digital-to-analog converter (DAC) 310, the TX path 302 can 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 can be included in one or more radio frequency integrated circuits (RFICs). For some specific implementations, the PA 318 can be external to the RFIC.

[0052] BBF 312 filters the baseband signal received from DAC 310, and 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., up-converted from baseband to radio frequency). This frequency conversion process generates a sum frequency and a difference frequency between the LO frequency and the frequency of the baseband signal of interest. These sum and difference frequencies are referred to as beat frequencies. The beat frequencies are typically in the RF range, such that the signal output by mixer 314 is typically an RF signal, which can be amplified by DA 316 and / or by PA 318 before being transmitted through antenna 306. Although one mixer 314 is illustrated, several mixers can be used to up-convert the filtered baseband signal to one or more intermediate frequencies and then up-convert the intermediate frequency signal to the frequency for transmission.

[0053] RX path 304 can include a low noise amplifier (LNA) 324, a mixer 326, and a baseband filter (BBF) 328. LNA 324, mixer 326, and BBF 328 can be included in one or more RFICs, which can be the same RFIC as the RFIC including the TX path components or can be a different RFIC. The RF signal received via antenna 306 can be amplified by LNA 324, and 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-converted). The baseband signal output by mixer 326 can be filtered by BBF 328 before being converted to a digital I or Q signal by analog-to-digital converter (ADC) 330 for digital signal processing.

[0054] Some transceivers can employ a frequency synthesizer with a voltage controlled oscillator (VCO) to generate a stable, tunable LO frequency with a specific tuning range. Thus, the transmit LO frequency can be generated by TX frequency synthesizer 320, which can be buffered or amplified by amplifier 322 before being mixed with the baseband signal in mixer 314. Similarly, the receive LO frequency can be generated by RX frequency synthesizer 332, which can be buffered or amplified by amplifier 334 before being mixed with the RF signal in mixer 326.

[0055] The controller 336 can direct the operation of the RF transceiver circuit 300, such as transmitting signals via the TX path 302 and / or receiving signals via the RX path 304. The controller 336 can 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 components, discrete hardware components, or any combination thereof. The memory 338 can store data and program code for operating the RF transceiver circuit 300. The controller 336 and / or the memory 338 can include control logic. In some cases, the controller 336 can determine the transmit power applied to the TX path 302 (e.g., certain gain levels applied at the BBF 312, DA 316, and / or PA 318) in accordance with RF exposure limits set by country-specific regulations and / or international standards, as further described herein.

[0056] Example RF exposure compliance

[0057] RF exposure can be expressed in terms of the specific absorption rate (SAR), which measures the energy absorption of human tissue per unit mass and can have the unit of watts per kilogram (W / kg). RF exposure can also be expressed in terms of the power density (PD), which measures the energy absorption per unit area and can have the unit of milliwatts per square centimeter (mW / cm 2 ). In some cases, maximum permissible exposure (MPE) limits (in the form of PD) can be imposed on wireless devices using transmit frequencies above 6 GHz. The 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 / m 2 ) averaged over the defined area and time-averaged over a frequency-dependent time window) to prevent human exposure hazards represented by tissue temperature changes.

[0058] The SAR can be used to evaluate RF exposure for transmit frequencies below 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. The PD can be used to evaluate RF exposure for transmit frequencies above 6 GHz, which covers wireless communication technologies such as IEEE 802.11ad, 802.11ay, 5G in the millimeter wave band, etc. Thus, different metrics can be used to evaluate RF exposure for different wireless communication technologies.

[0059] A wireless device (e.g., UE 120) may use multiple wireless communication technologies to transmit signals simultaneously. For example, the wireless device may use a first wireless communication technology operating below 6 GHz (e.g., 3G, 4G, 5G, etc.) and a second wireless communication technology operating above 6 GHz (e.g., millimeter-wave 5G in the 24 GHz to 60 GHz band, IEEE 802.11ad or 802.11ay) to transmit signals simultaneously. In some aspects, the 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 by 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 by PD) to transmit signals simultaneously. As used herein, the sub-6 GHz band may include, in some examples, the band from 300 MHz to 6,000 MHz, and in some examples, may include bands in the range of 6,000 MHz and / or 7,000 MHz.

[0060] In certain 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 millimeter-wave or 60 GHz bands, 100 seconds or 360 seconds for bands ≤ 6 GHz, etc.).

[0061] Figure 4A FIG. 400A is a graph of the transmit power (P(t)) over time that varies within a time window (T) associated with a time-averaged RF exposure limit, according to certain aspects of the present disclosure. For example, at certain transmission instances within the time window (T), the instantaneous transmit power may exceed the maximum time-averaged transmit power level (P limit ). In some cases, the maximum time-averaged transmit power level may account for uncertainties in the transceiver circuitry, such as temperature drift, component age, etc. The transmit power may be greater than the maximum time-averaged transmit power level P limit . In certain cases, the UE may transmit at P max , where P max is the maximum transmit power supported by the UE. In some cases, at certain transmission instances, the UE may transmit at a power less than or equal to the maximum time-averaged transmit power level P limit . The maximum time-averaged transmit power level P limit represents a time-averaged threshold for the transmit power with respect to the RF exposure limit within the time window (T), and in certain cases, P limitmay be referred to as the maximum time-averaged power level or limit, or, in terms of exposure, may be referred to as the maximum time-averaged RF exposure level or limit. In some cases, the maximum time-averaged transmit power level P limit may correspond to the maximum allowable transmit power as described herein. FIG. 400A also illustrates the gaps between transmission bursts, where these gaps represent periods during which no transmission is output from the device.

[0062] In some cases, the transmit power may be maintained at the maximum time-averaged transmit power level allowed for RF exposure compliance such that continuous transmission can be performed during a time window (e.g., P limit ). For example, Figure 4B is a graph 400B of transmit power (P(t)) over time according to certain aspects of the present disclosure, which illustrates an example in which the transmit power is limited to P limit . As shown, the UE may follow the RF exposure limit to transmit continuously at P limit .

[0063] Figure 4C is a graph 400C of transmit power (P(t)) over time illustrating a time-averaging pattern according to certain aspects of the present disclosure, which provides reserved power to enable continuous transmission within a time window (T). As shown, the transmit power may be backed off from the maximum instantaneous power (P max ) to the reserved power (P reserve ) such that the UE may continue to transmit at a lower power (P reserve ) to maintain continuous transmission (e.g., maintain a radio connection with a receiving entity) during the time window. In Figure 4C , the area between P max and P max and P reserve during the duration of P limit and P reserve in the time window T may be equal such that Figure 4C the area of the transmit power (P(t)) in limit is equal to the area of P reserve in the time window T. Such an area may be considered to use 100% of the energy (transmit power or exposure) to maintain compliance with the time-averaged RF exposure limit. In the absence of the reserved power P max , the transmitter may transmit at P reserve for a portion of the time window and the transmitter may be turned off for the remainder of the time window to ensure compliance with the time-averaged RF exposure limit. In some aspects, P maxThe transmission duration below can 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., transmit in short bursts at P max below).

[0064] In some aspects, in the time-averaging mode illustrated in Figure 4C , the UE can transmit at a power higher than the average power level but less than P max . Although a single transmission burst is illustrated in Figure 4C , it should be understood that the UE may instead utilize multiple transmission bursts within a time window (T), e.g., as described herein with respect to Figure 4A , where these transmission bursts can be separated by time periods during which the transmission power is maintained at or below P reserve . Additionally, it should be understood that the transmission power of each transmission burst can vary (within the burst and / or compared to other bursts), and at least a portion of the burst can be transmitted at a power higher than the maximum average power level (e.g., P limit ).

[0065] Although Figures 4A to 4C illustrates continuous transmissions within a window, timing, burst, etc., it should be understood that a transmission duty cycle can be implemented. In such embodiments, the transmission power can be periodically zero and maintained at a higher level during other portions of the duty cycle (e.g., at the level illustrated in Figures 4A to 4C ). As used herein, the duty cycle of a transmission can refer to the portion (e.g., 5 ms) of a specific time period (e.g., 500 ms) during which one or more signals are transmitted. In some cases, the duty cycle can be normalized (e.g., pre-determined) with a specific RAT, and / or can change over time, e.g., due to changes in radio conditions, mobility, and / or user behavior.

[0066] In some cases, a wireless communication device can use the maximum allowable transmission power (P limit ) corresponding to the time-averaged RF exposure limit to evaluate RF exposure compliance. The maximum allowable transmission power can correspond to the transmission power that satisfies the time-averaged RF exposure limit, assuming the wireless device transmits for the entire duration of a time window associated with the time-averaged RF exposure limit (e.g., 2 seconds for the mmWave or 60 GHz band, 100 seconds or 360 seconds for a band ≤ 6 GHz, etc.), e.g., as Figure 4BAs depicted. To ensure compliance with the time-averaged RF exposure limit, the wireless device may keep the transmit power no greater than the maximum allowable transmit power. Such a scheme can facilitate a simplified RF exposure assessment without having to determine the rolling average of the RF exposure within a given time window associated with the time-averaged RF exposure limit, and this scheme may be referred to as a non-averaged RF exposure assessment.

[0067] In some cases, a wireless device may be equipped with multiple radios for wireless communication, such as Code Division Multiple Access (CDMA), Evolved Universal Terrestrial Radio Access (E-UTRA), 5th Generation New Radio (5G NR), IEEE 802.11, Bluetooth, non-terrestrial networks, etc. For example, some wireless devices may support multi-mode (e.g., E-UTRA and 5G NR, 5G NR and IEEE 802.11, etc.) and / or multi-band (e.g., sub-6 GHz band and mmWave band) communication via multiple transmit antennas (or radios) for simultaneous or concurrent transmission. To ensure compliance with the RF exposure limit, the wireless device may limit the maximum combined instantaneous transmit power for multi-mode / multi-band communication.

[0068] To account for multi-radio communication, the wireless device may be configured with a per-radio maximum allowable transmit power for each transmit scenario, which includes multi-radio scenarios (e.g., multi-mode / multi-band scenarios), where a transmit scenario may correspond to one or more radios, one or more frequency bands, one or more antennas, and / or one or more exposure scenarios (e.g., head exposure, limb exposure, body exposure, or hotspot exposure) for transmission within a time interval. The wireless device may be configured with a look-up table of per-radio maximum allowable transmit powers corresponding to various transmit scenarios, and the wireless device may use a specific value of the per-radio maximum allowable transmit power in the look-up table according to the transmit scenario. For a multi-radio scenario, the look-up table may have a pre-limited back-off (or pre-adjusted P limit ) for each radio in the radios.

[0069] For example, assume the wireless device has two radios. When using the radios concurrently or within the same time interval, the wireless device may have values of the maximum allowable transmit power for the first radio and the second radio for the transmit scenario. When using only the first radio, the wireless device may have a value of the maximum allowable transmit power associated with the first radio for the transmit scenario, and when using only the second radio, the wireless device may have another value of the maximum allowable transmit power associated with the second radio for the transmit scenario. The wireless device may have a per-radio maximum allowable transmit power for different frequency bands, different antennas, and / or different exposure scenarios.

[0070] Since the total transmit power that meets the RF exposure limit can vary according to the transmission scenario (e.g., frequency band, antenna, exposure scenario, etc.), a wireless device can be configured with the value of the maximum allowable transmit power per radio for multiple transmission scenarios. Since the maximum allowable transmit power per radio for each transmission scenario is determined under RF exposure testing, it takes time and other resources (e.g., test equipment and / or simulation data) to perform the tests for each transmission scenario and populate a lookup table with the values of the maximum allowable transmit power per radio. In addition, such a lookup table may use a certain amount of memory storage on the wireless device.

[0071] Example RF exposure management for multiple radios

[0072] Aspects of the present disclosure provide apparatus and methods for multi-radio RF exposure management, e.g., without pre-populating a lookup table that has separate power limits for radios in a multi-radio scenario. A wireless device can sequentially evaluate the RF exposure compliance of each radio such that the combined transmit power determined for each radio at different time intervals in a sequence of time intervals complies with the RF exposure limit. For example, the wireless device can first determine the RF exposure and corresponding transmit power associated with a first time interval for one radio (e.g., the one radio is a higher-priority radio or a primary radio), and can use any remaining available RF exposure for another radio (e.g., a lower-priority radio or a secondary radio) in a second time interval after the first time interval. The wireless device can extend the sequential exposure evaluation to any number of radios. For example, a third time interval (which can be the same as or different from the second time interval) can be used for a third radio (e.g., a radio with an even lower priority or a tertiary radio), which can use the remaining exposure left over from the combined exposure of the first radio and the second radio. Different from some pre-populated static lookup tables, the maximum allowable transmit power of a lower-priority second radio may not be pre-limited for a given transmission scenario based on the maximum allowable transmit power of a higher-priority first radio, and the pair of allowable transmit powers may be stored in the lookup table for that scenario.

[0073] The apparatuses and methods for multi-radio RF exposure management described herein have the potential to achieve higher per-radio transmit power than other solutions, and thus may be beneficial for improving wireless communication performance (e.g., improving signal quality at a receiver, reducing latency, increasing throughput, etc.). For example, multi-radio RF exposure management may allow a wireless device to evaluate RF exposure per time interval and allocate any remaining exposure to other radios. Multi-radio RF exposure management may allow a wireless device to select a high-priority radio to preferentially allocate exposure, which may improve the wireless communication performance of a particular radio (e.g., the high-priority radio and / or other radios). Multi-radio RF exposure management may allow a wireless device to reduce the size of a lookup table of maximum allowable transmit power. Multi-radio RF exposure management may allow wireless device manufacturers to avoid performing exposure tests for multi-radio exposure scenarios and populating complex lookup tables as described hereinbefore. A wireless device may store per-radio maximum allowable transmit power for various transmission scenarios (e.g., frequency bands, antennas, exposure scenarios, etc.) associated with a single radio, rather than for various transmission scenarios (e.g., frequency bands, antennas, exposure scenarios, etc.) associated with various radio combinations (e.g., only the first radio, only the second radio, and / or a combination of the first radio and the second radio), where static limits for each radio are pre-populated for a given transmission scenario.

[0074] For some aspects, multi-radio RF exposure management may be performed using, for example, a centralized processing architecture at a modem (and / or processor) associated with one or more radios. Figure 5 is a diagram of an example processing architecture 500 for allocating energy across multiple radios according to some aspects of the present disclosure. For example, radios 502a - 502d (e.g., radio 1, radio 2, etc.) of a wireless device may report past RF exposure usage (or generation) to an RF exposure manager 510 (e.g., similar to Figure 1 the RF exposure manager 122), and the RF exposure manager 510 may provide the allowable transmit power (e.g., maximum allowable instantaneous transmit power) associated with a time interval to the radios 502a - 502d that will transmit during that time interval. The RF exposure manager 510 may use sequential exposure evaluation to determine the allowable transmit power, as further described herein.

[0075] It should be understood that the RF exposure manager 510 and / or radio depicted in the processing architecture 500 can be implemented in hardware, software, or a combination of both. For example, the RF exposure manager 510 and / or radio included in the processing architecture 500 can be implemented in a modem, RF circuitry (e.g., a transceiver), memory blocks, registers, processing blocks, and / or instructions (e.g., software code or executable instructions). The executable instructions can be stored in memory and executed on a processor (e.g., an application processor and / or a modem processor).

[0076] Figure 6A is a timing diagram 600A that illustrates an example of RF exposure management for a wireless device (e.g., UE 120) having two radios. In this example, the wireless device can have an RF exposure manager (e.g., Figure 5 the RF exposure manager 510 in), a first radio (e.g., Figure 5 the radio 1 in), and a second radio (e.g., Figure 5 the radio 2 in), for example, as described herein with respect to Figure 5 . The radios can (or are expected to) transmit during the same time period, and thus the assessment of RF exposure compliance takes into account the transmission activities of both radios. For example, the RF exposure manager can select the maximum allowable transmit power (P limit ) associated with the current transmission scenario (e.g., frequency band, antenna, exposure scenario, etc.) for the first radio, and the RF exposure manager can provide P limit to the first radio, such as the RF circuitry (e.g., transceiver circuitry 300) associated with the first radio. The RF exposure manager can select P limit from a look-up table for various transmission scenarios as described herein, the look-up table including values of P limit associated with the first radio. The first radio can follow the corresponding time-averaged RF exposure limit and transmit a signal at a transmit power 604 less than or equal to the corresponding P i during a first time interval 602 (Δt limit ). The RF exposure manager can obtain a transmit power report associated with the first radio for the first time interval 602 from the first radio. The transmit power report can include (or indicate) the transmit power 604 used by the first radio during the first time interval 602. For example, the transmit power report can include the average transmit power used by the first radio during the first time interval 602.

[0077] The RF exposure manager can determine the transmit power report associated with the second radio for a second time interval 606 (Δt i+1The maximum allowable instantaneous transmit power 608 associated with a second radio, where the second time interval 606 follows the first time interval 602 in time. In some cases, the second time interval 606 may be later in time than the first time interval 602 but not adjacent to the first time interval 602. When the RF exposure manager determines the maximum allowable instantaneous transmit power 608, the second time interval 606 can be a future time interval. The first time interval 602 and the second time interval 606 can be in a sequence of time intervals such that the first time interval 602 and the second time interval 606 are consecutive time intervals in the sequence. To determine the maximum allowable instantaneous transmit power 608 of the second radio, the RF exposure manager can determine the normalized exposure associated with the first radio for the first time interval 602. The normalized exposure associated with the first radio ( ) can be determined according to the following expression:

[0078] (1)

[0079] where can be the average transmit power used by the first radio within the first time interval 602 (e.g., in milliwatts (mW)), and is the maximum allowable transmit power associated with the first radio within the first time interval 602 (e.g., in mW). That is, the normalized exposure associated with the first radio can be equal to the transmit power used by the first radio within the first time interval 602 divided by the maximum allowable transmit power associated with the first radio.

[0080] The RF exposure manager can determine an exposure margin ( ) associated with the second radio based on the normalized exposure associated with the first radio, where the exposure margin is the remaining exposure available for the second radio. The exposure margin can be determined according to the following expression:

[0081] (2)

[0082] That is, as the normalized value of (P limit ), the exposure margin associated with the second radio can be equal to the difference between one and the normalized exposure associated with the first radio determined according to expression (1).

[0083] The RF exposure manager can determine the maximum allowable instantaneous transmit power ( ) associated with the second radio based on the exposure margin. For example, the maximum allowable instantaneous transmit power associated with the second radio can be determined according to the following expression:

[0084] (3)

[0085] wherein is the maximum allowable transmit power associated with a second radio for a current transmission scenario (e.g., frequency band, antenna, exposure scenario, etc.). That is, the maximum allowable instantaneous transmit power associated with the second radio may be equal to the product of the exposure margin and the maximum allowable transmit power (P limit ).

[0086] The RF exposure manager may provide the maximum allowable instantaneous transmit power determined for the second time interval to the RF circuitry (e.g., transceiver circuitry) associated with the second radio. The sum of the normalized exposure associated with the first radio within the first time interval 602 and the normalized exposure associated with the second radio within the second time interval 606 satisfies the RF exposure limit (e.g., normalized limit one). For example, the sum of the normalized exposures of the first radio and the second radio may be less than the normalized limit (e.g., one). In some cases, a reservation may be maintained for the second radio or one or more other radios (such as a third radio), as further described herein. In certain cases, the wireless device may use the first radio to transmit another signal at a transmit power 610 within the second time interval 606. Such transmissions may be used to determine the transmit power of the second radio within a next time interval (not shown), e.g., as described herein with respect to Figure 6B as described.

[0087] In some aspects, the RF exposure manager may determine the maximum allowable instantaneous transmit power based on the duty cycle associated with the radio. The duty cycle may indicate the maximum amount of time the expected radio is to transmit within a certain time period. In some cases, the duty cycle may be configured according to a particular radio access technology (such as a time division duplex (TDD) uplink-downlink mode associated with the Global System for Mobile Communications (GSM), LTE, and / or NR). For example, for the first time interval 602, the RF exposure manager may determine the maximum allowable instantaneous transmit power (MAIP_first) associated with the first radio according to the following expression:

[0088] (4a)

[0089] where duty_cycle represents the duty cycle associated with the first radio for the first time interval. For the second time interval 606, the RF exposure manager may determine the maximum allowable instantaneous transmit power (MAIP_sec) of the second radio according to the following expression:

[0090] (4b)

[0091] where duty_cycle represents the duty cycle associated with a second radio for a second time interval.

[0092] The RF exposure management described herein may allow a wireless device to store a maximum allowable transmit power (P limit ) for various transmit scenarios per radio (e.g., frequency band, antenna, exposure scenario, etc.), such as without a multi-radio combination that pre-limits the per-radio transmit power. The described RF exposure management may allow the wireless device to consider the actual transmit power used by a primary radio to determine the maximum allowable instantaneous transmit power associated with a secondary radio. The RF exposure management described herein may be applied in conjunction with a time averaging implementation for RF exposure compliance, such as as described herein with respect to Figures 4A to 4C . For example, the wireless device may switch between performing the RF exposure management described herein and applying the time averaging implementation. The time averaging implementation may include the wireless device determining a maximum allowable transmit power (e.g., P limit ) in a future time interval that meets the RF exposure limit based on past transmit power in a time window associated with a time-averaged RF exposure limit.

[0093] In some aspects, a wireless device may have antennas arranged in antenna groups, where an antenna group may include one or more antennas (or antenna modules) associated with one or more radios. The antenna groups may be configured and / or operated to be mutually exclusive with respect to RF exposure from one another. That is, for example, due to the antenna groups being arranged at different locations on the wireless device, the RF exposure generated by one antenna group may have no effect on the RF exposure generated by another antenna group. RF exposure compliance and corresponding transmit power levels may be determined separately for each antenna group, thus allowing multiple antenna groups to transmit during the same time period. The RF exposure compliance for the antenna groups may be performed in parallel (e.g., concurrently together). In some cases, the wireless device may perform the multi-radio RF exposure management described herein with respect to the antenna groups. The wireless device may store the maximum allowable transmit power associated with the radios of each antenna group, and the wireless device may evaluate the RF exposure compliance of the multiple radios of each antenna group. For example, in the case of a transmit during the same time period involving antennas from different antenna groups, the radios associated with the antenna groups may transmit up to the respective maximum allowable transmit power as described herein (e.g., P limit ).

[0094] Since the multi-radio RF exposure management described herein uses normalized exposure and normalized energy allocation, a wireless device can evaluate RF exposure compliance across various frequency bands with different RF exposure limits, such as sub-6 GHz bands and / or mmWave bands. For example, a first radio can be configured to transmit signals in a sub-6 GHz band, and a second radio can be configured to transmit signals in a mmWave band.

[0095] In some aspects, the RF exposure manager can select a first radio among a plurality of radios having transmissions to be output within a first time interval 602 (e.g., Figure 5 radios 1 through 4 in ). For example, the RF exposure manager can identify that the first radio has a higher priority than other radios to be allocated energy within the first time interval 602. The priority associated with a radio can be based on one or more criteria, which, as illustrative non-limiting examples, can be such as duty cycle, frequency band, quality of service (QoS) characteristics (e.g., latency, data rate, priority level, etc.), and type of service (e.g., URLLC, eMBB, Internet of Things (IoT), voice traffic, video traffic, interactive gaming, mission-critical data, etc.).

[0096] Figure 6B is illustrative Figure 6ATiming diagram 600B of an example of RF exposure management depicted therein, which is performed within a time window (T) associated with a time-averaged RF exposure limit. In this example, the RF exposure manager determines the maximum allowable exposure of a second radio within a future time interval (e.g., second time interval 606) based on the past exposure of a first radio within a past time interval (e.g., first time interval 602). The sum of the normalized exposures of the first radio and the second radio can meet the RF exposure limit (e.g., normalized limit one). For example, a set of normalized exposures 612 including a first exposure 614 associated with the first radio and a second exposure 616 associated with the second radio can meet the RF exposure limit. Each of the normalized exposures in the normalized exposures can correspond to a different time interval in a sequence of time intervals (e.g., first time interval 602 and second time interval 606). The RF exposure manager can continue to perform RF exposure assessment for the second radio within a future time interval based on the transmit power of the first radio within a past interval. The RF exposure manager can determine the maximum allowable instantaneous transmit power associated with the second radio for a future time interval based on the past exposure generated by the first radio within a past time interval. Assuming that the duration of the time intervals (e.g., Δt) in which the first radio and the second radio are located is much less than the time window (T) associated with the time-averaged RF exposure limit, the average total exposure obtained within this time window will comply with the time-averaged RF exposure limit. For example, each of the first time interval 602 and the second time interval 606 can be a part of the time window (T) associated with the time-averaged RF exposure limit.

[0097] In some aspects, the multi-radio RF exposure management described herein can be applied to more than two radios transmitting within the same time period. For example, the exposure margin remaining for the first radio can be used for the second radio, and the remaining exposure margin can be used for the third radio.

[0098] It should be noted that in some cases, the duration of the time intervals (e.g., Δt) in which the first radio and the second radio (or generally any radio of a wireless device) are located may be less than the regulatory time window. For example, the regulatory time window can be the time window (T) associated with an RF exposure limit such as a time-averaged RF exposure limit. Generally, the multi-radio RF exposure management described herein can implement time intervals with any applicable duration.

[0099] Figure 7A is a timing diagram 700A illustrating an example of RF exposure management for a wireless device (e.g., UE 120) having three radios. In this example, the wireless device can have an RF exposure manager (e.g., Figure 5the RF exposure manager 510), a first radio (e.g., Figure 5 radio 1 in Figure 5 ), a second radio (e.g., Figure 5 radio 2 in Figure 5 ), and a third radio (e.g., Figure 6A radio 3 in i+2 ), for example, as described herein with respect to i+1 Figure 5 i+1 ). The RF exposure manager may perform the same operations on the first radio and the second radio, as described herein with respect to

[0100] Figure 6A . In this example, when the RF exposure manager determines the maximum allowable instantaneous transmit power 714 of the third radio within the third time interval 712 (Δt

[0101] (5)

[0102] ), the second time interval 606 (Δt ), the third time interval may be a past time interval and may follow the second time interval 606 in time. In some cases, the third time interval 712 may be later in time than the second time interval 606 but not adjacent to the second time interval 606. The second radio may comply with the corresponding time-averaged RF exposure limit and transmit a signal at a transmit power 708 less than or equal to the corresponding maximum allowable instantaneous transmit power within the second time interval 606 (Δt ). The RF exposure manager may obtain a transmit power report associated with the second radio for the second time interval 606 from the second radio. The transmit power report may include or indicate the transmit power 708 (e.g., average transmit power) used by the second radio within the second time interval 606. limit ), i.e., as a normalized value of (P

[0103] The RF exposure manager may determine the maximum allowable instantaneous transmit power 714 associated with a third radio based on an exposure margin. For example, the maximum allowable instantaneous transmit power associated with the third radio ( ) may be determined according to the following expression:

[0104] (6)

[0105] where is the maximum allowable transmit power associated with the third radio for the current transmit scenario (e.g., frequency band, antenna, exposure scenario, etc.). That is, the maximum allowable instantaneous transmit power associated with the third radio may be equal to the product of the available remaining exposure margin and the maximum allowable transmit power (P limit ). Here, the RF exposure manager may also consider the duty cycle associated with the third radio. For example, the maximum allowable instantaneous transmit power (MAIP_third) associated with the third radio may be determined according to the following expression:

[0106] (7)

[0107] where duty_cycle represents the duty cycle associated with the third radio for the third time interval 712.

[0108] The RF exposure manager may provide the maximum allowable instantaneous transmit power determined for the third time interval to an RF circuit (e.g., transceiver circuit) associated with the third radio. The sum of the normalized exposure associated with the first radio in the first time interval 602, the normalized exposure associated with the second radio in the second time interval 606, and the normalized exposure associated with the third radio in the third time interval 712 satisfies an RF exposure limit (e.g., normalized limit one). For example, the sum of the normalized exposures of the first radio, the second radio, and the third radio may be less than the normalized limit (e.g., one). In some cases, the wireless device may use the first radio to transmit a signal at transmit power 716 and the second radio to transmit another signal at transmit power 718 in the third time interval 712. Such transmissions may be used to determine the transmit power of the third radio in a future time interval (not shown), e.g., as described herein with respect to Figure 7B .

[0109] Figure 7B is illustrative Figure 7ATiming diagram 700B of an example of RF exposure management depicted therein, the RF exposure management being performed within a time window (T) associated with a time-averaged RF exposure limit. In this example, the RF exposure manager determines the maximum allowable exposure of a third radio within a future time interval (e.g., third time interval 712) based on the past exposures of a first radio and a second radio within respective past time intervals (e.g., first time interval 602 and second time interval 606). The sum of the normalized exposures of the first radio, the second radio, and the third radio may satisfy the RF exposure limit (e.g., normalized limit one). For example, a set of normalized exposures 720 including a first exposure 722 associated with the first radio, a second exposure 724 associated with the second radio, and a third exposure 726 associated with the third radio may satisfy the RF exposure limit, where each of the normalized exposures in the normalized exposures corresponds to a different time interval in a sequence of time intervals (e.g., first time interval 602, second time interval 606, and third time interval 712). The RF exposure manager may continue to perform RF exposure assessments on the radios, as described herein with respect to Figure 7A as described.

[0110] The transmit power available for a low-priority radio is based on the exposure margin remaining for a high-priority radio. In the case where the high-priority radio transmits at its P limit there will be no margin available for the low-priority radio to transmit a signal. Since in the operations described herein with respect to Figure 6A and Figure 7A the radios are allowed to consume all of the exposure margin, the wireless device may reserve a certain amount of energy for some radios, such as the second radio described with respect to Figure 6A or the second radio and / or the third radio described with respect to Figure 7A To avoid dropping the link of the low-priority radio, the transmit power of the high-priority radio may be less than or equal to a certain percentage (x) of P limit .

[0111] In a dual-radio example, the transmit power of the first radio is allowed not to exceed the product of x and P limit ( ), where x is less than 1.0, thus ensuring that the second radio has at least margin. In some aspects, the RF exposure manager may consider the duty cycle associated with the first radio. For example, the RF exposure manager may determine the maximum allowable instantaneous transmit power (MAIP_first) associated with the first radio as the product of x and P limit divided by the duty cycle (e.g., ). The RF exposure manager can determine the normalized exposure associated with the first radio, as provided in expression (1). The RF exposure manager can determine any remaining exposure margin for the second radio according to the following expression ( ):

[0112] (8)

[0113] where x is the reservation or power limit associated with the first radio. That is, the remaining exposure margin for the second radio can be equal to the difference between the reservation and the exposure margin. The RF exposure manager can determine the exposure margin associated with the second radio according to the following expression:

[0114] (9)

[0115] The RF exposure manager can determine the maximum allowable instantaneous transmit power (MAIP_sec) associated with the second radio based on the corresponding exposure margin (e.g., according to expression (3)) and in some cases based on the duty cycle (e.g., according to expression (4b)). In some aspects, the RF exposure manager can ignore the remaining exposure margin. The RF exposure manager can apply a predetermined allocation to each radio in the radio, e.g., allocate a normalized exposure margin (e.g., 70%) to the first radio, and allocate a normalized exposure margin (1 - ) (e.g., 30%) to the second radio.

[0116] In some aspects, the reservation can be applied to additional radios. In a three-radio example, the first reservation (x) can represent the maximum energy that can be assigned to the first radio, and the second reservation (y) can represent the maximum energy that can be assigned to the second radio, where the remaining exposure margin is reserved for the third radio (e.g., ), and the sum of the first reservation and the second reservation is less than one ( ). For example, the RF exposure manager can determine the exposure margin associated with the second radio according to expression (9). In some cases, the RF exposure manager can determine the exposure margin associated with the second radio based on the second reservation (y):

[0117] (10)

[0118] The RF exposure manager can determine the maximum allowable instantaneous transmit power (MAIP_sec) associated with the second radio based on the corresponding exposure margin (e.g., according to expression (3)) and in some cases based on the duty cycle (e.g., according to expression (4b)).

[0119] The RF exposure manager may determine the normalized exposure generated by a second radio during a time interval (e.g., the second time interval 606) according to the following expression:

[0120] (11)

[0121] The RF exposure manager may determine any remaining margin for a third radio according to the following expression ( ):

[0122] (12)

[0123] where may represent the exposure margin associated with the second radio, as determined according to expression (9). That is, the remaining margin for the third radio may be equal to the difference between the exposure margin associated with the second radio and the exposure generated by the second radio. The RF exposure manager may determine the exposure margin associated with the third radio according to the following expression:

[0124] (13)

[0125] where y is the reservation or power limit associated with the second radio. The RF exposure manager may determine the maximum allowable instantaneous transmit power associated with the third radio, for example, according to expression (6), based on the corresponding exposure margin. In some cases, the maximum allowable instantaneous transmit power (MAIP_third) associated with the third radio may be determined, for example, according to expression (7), based on the duty cycle associated with the third radio. In some aspects, the RF exposure manager may not consider the remaining exposure margin. The RF exposure manager may apply a predetermined allocation to each of the radios, e.g., allocate a normalized exposure margin to the first radio, a normalized exposure margin to the second radio, and a normalized exposure margin (1 - ) to the third radio.

[0126] As an example of the allocation among N active radios, the wireless device may allocate a portion of the exposure margin among the first N - 1 radios, while the remaining portion may be allocated to the Nth radio. In this example, x1 to x N-1 represent the minimum percentages of the exposure allocation for the first N - 1 radios, and the Nth radio receives the remaining portion (e.g., 1 – (x1 + x2 +.. + x N-1 ), where the sum of the allocations for the first N - 1 radios may be less than one (e.g., x1 + x2 + … + x N-1< 1.0). For each of the radios, an exposure associated with the given radio and a remaining exposure margin for other radios may be determined after the given radio transmits within a time interval (eg, Δt or the first time interval 602).

[0127] For the first radio (Radio 1), the wireless device may determine the exposure margin according to the following expression:

[0128]

[0129] For the first radio, the wireless device may determine the maximum allowable instantaneous transmit power (MAIP_radio1) according to the following expression:

[0130]

[0131] For the first radio, the wireless device may determine the RF exposure generated by the first radio as follows:

[0132]

[0133] For the first radio, the wireless device may determine the remaining exposure for other radios as follows:

[0134]

[0135] For the second radio (Radio 2), the wireless device may determine the exposure margin according to the following expression:

[0136]

[0137] For the second radio, the wireless device may determine the maximum allowable instantaneous transmit power (MAIP_radio2) according to the following expression:

[0138]

[0139] For the second radio, the wireless device may determine the RF exposure caused by the first radio as follows:

[0140]

[0141] For the second radio, the wireless device may determine the remaining exposure for the other radios as follows:

[0142]

[0143] For the (N-1)th radio, the wireless device may determine the exposure margin according to the following expression:

[0144]

[0145] For the (N-1)th radio, the wireless device can determine the maximum allowable instantaneous transmit power (MAIP_radio N-1 ):

[0146]

[0147] For the (N-1)th radio, the wireless device can determine the RF exposure generated by the first radio as follows:

[0148]

[0149] For the (N-1)th radio, the wireless device can determine the remaining exposure for other radios as follows:

[0150]

[0151] For the Nth radio, the wireless device can determine the remaining exposure margin as follows:

[0152]

[0153] For the Nth radio, the wireless device can determine the maximum allowable instantaneous transmit power (MAIP_radioN) as follows:

[0154]

[0155] In some aspects, the RF exposure manager may not consider the remaining exposure margin. The RF exposure manager can apply a predetermined allocation to each radio in the radio, for example, allocate a normalized exposure margin to the first radio , allocate a normalized exposure margin to the second radio , and so on, allocate a normalized exposure margin to the (N-1)th radio , and allocate a normalized exposure margin to the Nth radio (1 – ).

[0156] In some aspects, the RF exposure manager can split the exposure margin associated with the second radio between the second radio and any other radio (e.g., the third radio) ( ), rather than determine a separate exposure margin for the third radio according to expression (13). Generally speaking, for the N-radio scenario, the total exposure margin can be allocated between radios without considering any remaining margin or based on the remaining margin, for example, as described herein according to expressions (8) to (13).

[0157] Note that, in some cases, the duration of the time interval (e.g., Δt) in which the first radio, the second radio, and the third radio (or generally any radio of a wireless device) are located may be less than the regulatory time window. For example, the regulatory time window may be a time window (T) associated with RF exposure limits such as time-averaged RF exposure limits. Generally, the multi-radio RF exposure management described herein can implement time intervals with any applicable duration.

[0158] Figure 8 is a flow chart illustrating an example operation 800 for wireless communication in accordance with certain aspects of the present disclosure. Operation 800 may be performed, for example, by a wireless device (e.g., UE 120a in wireless communication network 100). Operation 800 may be implemented as a software component executed and run on one or more processors (e.g., Figure 2 the controller / processor 280). Additionally, the signal transmission and / or reception by the wireless device in operation 800 may be implemented, for example, by one or more antennas (e.g., Figure 2 the antenna 252). In certain aspects, the transmission and / or reception of signals by the wireless device may be implemented by obtaining and / or outputting signals via a bus interface of one or more processors (e.g., controller / processor 280).

[0159] Operation 800 may optionally begin at block 802, where the wireless device may determine a first exposure associated with a first radio for a first transmission within a first time interval (e.g., first time interval 602). For example, the wireless device may determine a normalized exposure associated with the first radio according to expression (1), as described herein with respect to Figure 6A In certain aspects, the wireless device may determine the first exposure at least in part based on a first maximum time-averaged transmission power level (P limit_first ) associated with the first radio.

[0160] At block 804, the wireless device may determine a first allowable transmission power associated with a second radio for a second time interval (e.g., second time interval 606) at least in part based on the first exposure associated with the first radio. For example, the wireless device may determine a maximum allowable instantaneous transmission power associated with the second radio according to expression (3) or (4b), as described herein with respect to Figure 6A In certain aspects, the wireless device may further determine the first allowable transmission power based on a second maximum time-averaged transmission power level (P limit_sec ) associated with the second radio. The second time interval may be adjacent in time to the first time interval.

[0161] At block 806, the wireless device may transmit a first signal at a first transmit power during a second time interval using a second radio based on a first allowable transmit power. The first transmit power may be less than or equal to the first allowable transmit power determined at block 804. In some cases, the wireless device may transmit a second signal at a second transmit power during the second time interval using a first radio. The second transmit power may be less than or equal to a second allowable transmit power. The second allowable transmit power (e.g., MAIP_first) may be determined based at least in part on an exposure margin assigned to the first radio and a first maximum time-average transmit power level associated with the first radio. The exposure margin assigned to the first radio may be one. In some cases, the wireless device may determine a maximum allowable instantaneous transmit power associated with the first radio based on a duty cycle associated with the first radio, e.g., according to expression (4a).

[0162] In some aspects, the first allowable transmit power associated with the second radio may be based on an exposure margin. To determine the first allowable transmit power, the wireless device may determine a first exposure margin associated with the second radio based on a first exposure associated with the first radio, e.g., according to expression (2). The wireless device may determine the first allowable transmit power based on the first exposure margin and a second maximum time-average transmit power level associated with the second radio (e.g., P limit_sec )). To determine the first allowable transmit power, the wireless device may determine the first exposure margin as a difference between one and the first exposure, e.g., according to expression (2). To determine the first allowable transmit power, the wireless device may determine the first allowable transmit power as a product of the first exposure margin and the first maximum time-average transmit power level, e.g., according to expression (3).

[0163] In some aspects, the wireless device may determine a second exposure margin for the second radio as a difference between one and a third exposure margin (e.g., x) assigned to the first radio (e.g., 1 – x). The wireless device may determine an available exposure margin as a difference between the third exposure margin (x) assigned to the first radio and a first exposure (e.g., x – norm.exp.first). The wireless device may determine the first exposure margin as a sum of the second exposure margin and the available exposure margin (e.g., (1 – x) + (x – norm.exp.first) = (1 – norm.exp.first)). In some cases, the third exposure margin assigned to the first radio may be one. The entire exposure margin may be assigned to a particular radio.

[0164] In some cases, a wireless device may determine a first allowable transmit power based on, for example, the duty cycle associated with a second radio according to expression (4b). The duty cycle may represent the maximum amount of time that the second radio is expected to transmit during a certain time period. If the duty cycle associated with the second radio is low (e.g., < 50%), the second radio may be able to transmit at a higher transmit power. If the duty cycle associated with the second radio is high (e.g., > 50%), a lower transmit power may be allocated to the second radio.

[0165] For some aspects, a wireless device may determine the transmit power of a third radio or more radios, e.g., as described herein with respect to Figure 7A The wireless device may determine, for example, according to expression (5), a second exposure margin associated with a third radio for use in a third time interval (e.g., third time interval 712) based on a first exposure margin and a second exposure associated with the second radio for a second transmission during a second time interval. The wireless device may determine, for example, according to expression (6), a second allowable transmit power associated with the third radio for use in the third time interval based on the second exposure margin and a second maximum time-average transmit power level associated with the third radio (e.g., P limit_third ).

[0166] In some cases, the wireless device may determine a third exposure margin (e.g., 1 - x - y) for the third radio as the difference between one and the sum of two items: the minimum exposure margin (x) allocated to the first radio and the minimum exposure margin (y) allocated to the second radio. The wireless device may determine an available exposure margin (e.g., norm.exp.margin.sec - norm.exp.sec) as the difference between the first exposure margin (norm.exp.margin.sec) allocated to the second radio and the second exposure (norm.exp.sec). The wireless device may determine the second exposure margin as the sum of the third exposure margin for the third radio and the available exposure margin (e.g., (1 - x - y) + (norm.exp.margin.sec - norm.exp.sec)).

[0167] The wireless device may use a third radio to transmit a second signal at a second transmit power during a third time interval based on a second allowable transmit power. For example, the second transmit power may be less than or equal to the second allowable transmit power. The third time interval may have the same duration as the second time interval or a different duration from the second time interval. The third time interval may be adjacent to the second time interval in time, and the second time interval may be between the first time interval and the third time interval in time. In some cases, the wireless device may use a first radio to transmit a third signal during the third time interval and use a second radio to transmit a fourth signal during the third time interval. In some cases, the wireless device may determine the second allowable transmit power based on a duty cycle associated with the third radio.

[0168] In some aspects, the wireless device may reserve energy for some radios. For example, to determine the first allowable transmit power, the wireless device may further determine the first allowable transmit power based on a first power limit applied to the first radio, for example, according to expressions (8) and (9). To determine the second allowable transmit power, the wireless device may further determine the second allowable transmit power based on a second power limit applied to the second radio, for example, according to expressions (11) to (13).

[0169] For some aspects, antenna groups with mutually exclusive RF exposure may be assigned to the wireless device. The wireless device may determine a second allowable transmit power associated with a third radio, which is associated with a first antenna group, where the first radio and the second radio are associated with a second antenna group. The determination of the second allowable transmit power may be independent of the transmission associated with the second antenna group.

[0170] In some aspects, radios may be associated with different frequency bands and corresponding RF exposure limits. For example, the wireless device may use a first radio to transmit a second signal in a sub-6 GHz band, and the wireless device may use a second radio to transmit a first signal in a mmWave band.

[0171] For some aspects, the wireless device may select a first radio among these radios based on one or more priorities associated with multiple radios. For example, the wireless device may select the first radio based on the first radio having a higher priority than other radios. The first radio may have a higher transmit priority than the second radio. For example, the duty cycle may represent the priority, where the duty cycle of the first radio may be greater than that of the second radio. In some cases, the service type may indicate the priority. For example, the first radio may be used to transmit interactive game traffic, while the second radio may be used to transmit session voice traffic. Therefore, in such scenarios, the first radio has a higher transmit priority than the second radio.

[0172] For some aspects, a wireless device may allocate an exposure margin among radios. For example, the wireless device may determine a first exposure margin for a first radio and a second exposure margin for any other radio, where the sum of the first exposure margin and the second exposure margin may be less than or equal to a threshold (e.g., 1). The wireless device may allocate a portion of the second exposure margin to each of the other radios. In some cases, the wireless device may evenly allocate the portions of the second exposure margin to each of the other radios (e.g., (1 – norm.exp.first) / (N-1), where N is the total number of radios). In certain cases, the portions of the second exposure margin allocated among the other radios may vary. The wireless device may determine a first allowable transmit power associated with the first radio based on the first exposure margin, and the wireless device may determine a second allowable transmit power associated with each of the other radios based on the respective portions of the second exposure margin. The wireless device may transmit a first signal at a first transmit power during a first time interval based on the first allowable transmit power, and the wireless device may transmit a second signal at a second transmit power during a corresponding second time interval for each of the other radios based on the respective second allowable transmit power.

[0173] Although, for ease of understanding, Figures 1 to 8 the examples depicted herein are described with respect to a UE performing various methods for providing RF exposure compliance, aspects of the present disclosure may also apply to other wireless devices performing the RF exposure management described herein, such as wireless stations, access points, base stations, and / or customer premise equipment (CPE). Additionally, while these examples are described with respect to communication 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.

[0174] It should be understood that the multi-radio RF exposure management described herein may achieve desired wireless communication performance, such as reduced latency, increased uplink data rate, and / or extended communication range, for example, due to an increased exposure margin that may be assigned to multiple radios.

[0175] Example communication device

[0176] Figure 9 illustrates may include operations configured to perform the techniques disclosed herein, such as Figure 8A communication device 900 (e.g., UE 120) of various components (e.g., corresponding to component-plus-function components) for the illustrated operations. The communication device 900 includes a processing system 902 that can be coupled to a transceiver 908 (e.g., a transmitter and / or a receiver). The transceiver 908 is configured to transmit and receive signals for the communication device 900 via an antenna 910, such as the various signals described herein. The processing system 902 can be configured to perform the processing functions of the communication device 900, including processing signals received by the communication device 900 and / or to be transmitted by the communication device.

[0177] The processing system 902 includes a processor 904 coupled to a computer-readable medium / memory 912 via a bus 906. In some aspects, the computer-readable medium / memory 912 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 904, cause the communication device 900 to perform Figure 8 the illustrated operations 800 or other operations for performing the various techniques discussed herein for providing RF exposure compliance. In some aspects, the computer-readable medium / memory 912 stores code 914 for determination, code 916 for transmission (or output) or any combination thereof.

[0178] In some aspects, the processing system 902 has circuitry 920 configured to implement the code stored in the computer-readable medium / memory 912. In some aspects, the circuitry 920 is coupled to the processor 904 and / or the computer-readable medium / memory 912 via the bus 906. For example, the circuitry 920 includes circuitry 922 for determination, circuitry 924 for transmission (or output) or any combination thereof.

[0179] In some examples, the component for transmission or conveyance (or the component for output for transmission) may include Figure 2 the transceiver 254 and / or the antenna 252 of the illustrated UE 120 and / or Figure 9 the transceiver 908 and the antenna 910 of the communication device 900 in

[0180] In some cases, the device may not actually send, for example, signals and / or data, but may have an interface (a component for output) for outputting signals and / or data for transmission. For example, a processor may output signals and / or data for transmission to a radio frequency (RF) front end via a bus interface. Similarly, the device may not actually receive signals and / or data, but may have an interface (a component for acquisition) for obtaining signals and / or data received from another device. For example, a processor may obtain (or receive) signals and / or data for reception from the RF front end via a bus interface. 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 of.

[0181] In some examples, the component for determination may include various processing system components, such as: Figure 9 the processor 904 in; or Figure 2 aspects of the UE 120 depicted in, including a receive processor 258, a transmit processor 264, a TX MIMO processor 266, and / or a controller / processor 280.

[0182] Example aspects

[0183] Specific implementation examples are described in the following numbered clauses:

[0184] Aspect 1: A method for wireless communication by a wireless device, the method comprising: determining a first exposure associated with a first radio for a first transmission within a first time interval; determining a first allowable transmit power associated with a second radio for a second time interval at least in part based on the first exposure associated with the first radio; and transmitting a first signal at a first transmit power within the second time interval using the second radio based on the first allowable transmit power.

[0185] Aspect 2: The method according to Aspect 1, wherein: determining the first exposure includes determining the first exposure at least in part based on a first maximum time-average transmit power level associated with the first radio; and determining the first allowable transmit power includes further determining the first allowable transmit power based on a second maximum time-average transmit power level associated with the second radio.

[0186] Aspect 3: The method according to Aspect 1 or 2, the method further comprising: transmitting a second signal at a second transmit power within the second time interval using the first radio, wherein the first radio has a higher transmit priority than the second radio, and the second time interval is adjacent in time to the first time interval.

[0187] Aspect 4: The method according to aspect 3, wherein: the second transmission power is less than or equal to a second allowable transmission power; and the second allowable transmission power is at least partially based on an exposure margin assigned to the first radio and a first maximum time-averaged transmission power level associated with the first radio.

[0188] Aspect 5: The method according to aspect 4, the method further comprising: determining the second allowable transmission power based on a duty cycle associated with the first radio.

[0189] Aspect 6: The method according to aspect 4 or 5, wherein the exposure margin assigned to the first radio is less than or equal to one.

[0190] Aspect 7: The method according to any one of aspects 1 to 6, wherein determining the first allowable transmission power is further based on a duty cycle associated with the second radio.

[0191] Aspect 8: The method according to any one of aspects 1 to 7, wherein determining the first allowable transmission power includes: determining a first exposure margin associated with the second radio based on a first exposure associated with the first radio; and determining the first allowable transmission power based on the first exposure margin and a second maximum time-averaged transmission power level associated with the second radio.

[0192] Aspect 9: The method according to aspect 8, wherein determining the first allowable transmission power further includes determining the first exposure margin as the difference between one and the first exposure.

[0193] Aspect 10: The method according to aspect 8 or 9, wherein determining the first exposure margin includes: determining a second exposure margin for the second radio as the difference between one and a third exposure margin assigned to the first radio; and determining an available exposure margin as the difference between the third exposure margin assigned to the first radio and the first exposure; and determining the first exposure margin as the sum of the second exposure margin and the available exposure margin.

[0194] Aspect 11: The method according to aspect 10, wherein the third exposure margin assigned to the first radio is less than or equal to one.

[0195] Aspect 12: The method according to any one of aspects 8 to 11, wherein determining the first allowable transmission power further includes determining the first allowable transmission power as the product of the first exposure margin and the second maximum time-averaged transmission power level.

[0196] Aspect 13: The method according to aspect 8, the method further comprising: determining a second exposure margin associated with a third radio for a third time interval based on the first exposure margin and a second exposure associated with the second radio used for a second transmission during the second time interval; determining a second allowable transmission power associated with the third radio for the third time interval based on the second exposure margin and a second maximum time-average transmission power level associated with the third radio; and transmitting a second signal at a second transmission power using the third radio during the third time interval based on the second allowable transmission power.

[0197] Aspect 14: The method according to aspect 13, determining the second exposure margin includes: determining a third exposure margin for the third radio as the difference between one and the sum of a minimum exposure margin allocated to the first radio and a minimum exposure margin allocated to the second radio; determining an available exposure margin as the difference between the first exposure margin allocated to the second radio and the second exposure; and determining the second exposure margin as the sum of the third exposure margin for the third radio and the available exposure margin.

[0198] Aspect 15: The method according to aspect 13 or 14, wherein the third time interval has the same duration as the second time interval.

[0199] Aspect 16: The method according to any one of aspects 13 to 15, the method further comprising: transmitting a third signal using the first radio during the third time interval; and transmitting a fourth signal using the second radio during the third time interval, wherein the third time interval is adjacent in time to the second time interval, and wherein the second time interval is between the first time interval and the third time interval in time.

[0200] Aspect 17: The method according to any one of aspects 13 to 16, wherein determining the second allowable transmission power includes further determining the second allowable transmission power based on a duty cycle associated with the third radio.

[0201] Aspect 18: The method according to any one of aspects 13 to 17, wherein determining the second allowable transmission power includes further determining the second allowable transmission power based on a second power limit applied to the second radio.

[0202] Aspect 19: The method according to any one of aspects 1 to 18, wherein determining the first allowable transmission power includes further determining the first allowable transmission power based on a first power limit applied to the first radio.

[0203] Aspect 20: The method according to any one of aspects 1 to 19, the method further comprising: determining a second permissible transmit power associated with a third radio, the third radio being associated with a first antenna group, wherein the first radio and the second radio are associated with a second antenna group.

[0204] Aspect 21: The method according to aspect 20, wherein the determination of the second permissible transmit power is independent of the transmission associated with the second antenna group.

[0205] Aspect 22: The method according to any one of aspects 1 to 21, the method further comprising: using the first radio to transmit a second signal in a sub-6 GHz band, wherein transmitting the first signal comprises using the second radio to transmit the first signal in a mmWave band.

[0206] Aspect 23: The method according to any one of aspects 1 to 22, the method further comprising: selecting the first radio among the radios based on one or more priorities associated with a plurality of radios.

[0207] Aspect 24: An apparatus, the apparatus comprising: one or more memories that jointly store executable instructions; and one or more processors coupled to the one or more memories, the one or more processors being jointly configured to execute the executable instructions and cause the apparatus to perform the method according to any one of aspects 1 to 23.

[0208] Aspect 25: An apparatus, the apparatus comprising components for performing the method according to any one of aspects 1 to 23.

[0209] Aspect 26: A non-transitory computer-readable medium, the non-transitory computer-readable medium comprising computer-executable instructions that, 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 23.

[0210] Aspect 27: A computer program product embodied on a computer-readable storage medium, the computer-readable storage medium comprising code for performing the method according to any one of aspects 1 to 23.

[0211] The techniques described herein can be used in a variety of wireless communication technologies such as NR (e.g., 5G NR), 3GPP Long Term Evolution (LTE), LTE-Advanced (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. CDMA networks may implement radio technologies such as Universal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. cdma2000 covers the IS-2000, IS-95, and IS-856 standards. TDMA networks 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, etc. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). LTE and LTE-A are UMTS versions 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.

[0212] In 3GPP, the term "cell" can refer to the coverage area of a Node B (NB) and / or the NB subsystem serving that coverage area, depending on the context in which the term is used. In an NR system, the terms "cell" and BS, Next Generation Node B (gNB or gNodeB), Access Point (AP), Distributed Unit (DU), carrier, or Transmission and Reception Point (TRP) can be used interchangeably. A 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 geographical area (e.g., with a radius of several kilometers) and can allow unrestricted access for UEs with a service subscription. A pico cell can cover a relatively small geographical area and can allow unrestricted access for UEs with a service subscription. A femto cell can cover a relatively small geographical area (e.g., a home) and can allow restricted access by UEs associated with the femto cell (e.g., UEs in a Closed Subscriber Group (CSG), UEs of users in a home, etc.). The BS for a macro cell can be referred to as a macro BS. The BS for a pico cell can be called a pico BS. The BS for a femto cell can be referred to as a femto BS or a home BS.

[0213] A UE can also be referred to as a mobile station, terminal, access terminal, subscriber unit, station, customer premises equipment (CPE), cellular phone, smart phone, personal digital assistant (PDA), wireless modem, wireless device, handheld device, laptop computer, cordless phone, wireless local loop (WLL) station, tablet computer, camera, gaming device, netbook, smartbook, ultrabook, appliance, medical device or equipment, biometric sensor / device, wearable device (such as a smart watch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet, etc.)), entertainment device (e.g., music device, video device, satellite radio, etc.), vehicle component or sensor, smart meter / sensor, industrial manufacturing equipment, global positioning system device, or any other suitable device configured to communicate via wireless or wired media. Some UEs can be considered Machine-Type Communication (MTC) devices or Evolved MTC (eMTC) devices. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc. that can communicate with a BS, another device (e.g., a remote device), or some other entity. A wireless node can provide a connection to or for 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 can be considered Internet of Things (IoT) devices, which can be Narrowband IoT (NB-IoT) devices.

[0214] In some examples, access to an air interface can be scheduled. A scheduling entity (e.g., a BS) allocates resources for communication between some or all of the devices and equipment within the serving area or cell of the entity. The scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communication, the subordinate entities use the resources allocated by the scheduling entity. A base station is not the only entity that can be used as a scheduling entity. In some examples, a UE can be used as a scheduling entity and can schedule resources for one or more subordinate entities (e.g., one or more other UEs), and the other UEs can utilize the resources scheduled by the UE for wireless communication. In some examples, a UE can be used as a scheduling entity in a peer-to-peer (P2P) network or a mesh network. In a mesh network example, in addition to communicating with the scheduling entity, UEs can also communicate directly with each other.

[0215] The methods disclosed herein include one or more steps or acts for implementing the method. The steps and / or acts of the method may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of the steps or acts is specified, the order and / or use of specific steps and / or acts may be modified without departing from the scope of the claims.

[0216] As used herein, the term "processor," "at least one processor," or "one or more processors" generally refers to a single processor configured to perform one or more operations or multiple processors configured to jointly perform one or more operations. In the case of multiple processors, the execution of one or more operations may be divided among different processors, but one processor may perform multiple operations and multiple processors may jointly perform a single operation. Similarly, the term "memory," "at least one memory," or "one or more memories" generally refers to a single memory configured to store data and / or instructions or multiple memories configured to jointly store data and / or instructions.

[0217] As used herein, the phrase referring to "at least one of" a list of items refers to any combination of those items (which includes a single member). As an example, "at least one of a, b, or c" is intended to cover: a, b, c, a - b, a - c, b - c, and a - b - c, as well as any combination with multiple identical elements (e.g., a - a, a - a - a, a - a - b, a - a - c, a - b - b, a - c - c, b - b, b - b - b, b - b - c, c - c, and c - c - c, or any other ordering of a, b, and c).

[0218] As used herein, the term "determine" encompasses a variety of actions. For example, "determine" can include calculating, computing, processing, deriving, generating, investigating, looking up (e.g., looking up in a table, database, or another data structure), ascertaining, and the like. Additionally, "determine" can include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), etc. Further, "determine" can include parsing, selecting, picking, establishing, and the like.

[0219] The foregoing 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 readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language of the claims, wherein the reference to an element in the singular is not intended to mean "one and only one" but rather "one or more" unless specifically stated otherwise. The term "some," unless specifically stated otherwise, means one or more. All structural and functional equivalents of the elements of the various aspects described throughout this disclosure that are known or later will be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be covered by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public, whether or not such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. § 112(f), unless the element is expressly recited using the phrase "means for" or, in the case of a method claim, the phrase "step for."

[0220] The various operations of the foregoing method can be performed by any suitable component capable of performing the corresponding functions. The component can include various hardware and / or software components and / or modules, including but not limited to circuitry, an application specific integrated circuit (ASIC), or a processor. Generally speaking, where there are operations illustrated in the figures, those operations can have corresponding component-plus-function components with similar numbers.

[0221] The various illustrative logical blocks, modules, and circuits described in connection with the present disclosure may be implemented or performed 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 the 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, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0222] 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 particular application and overall design constraints of the processing system, the bus may include any number of interconnecting buses and bridges. The bus may link together various circuits, including a processor, machine-readable media, 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 the signal processing functions of the physical (PHY) layer. In the case of a UE (see Figure 1 ), a user interface (e.g., keypad, display, mouse, joystick, etc.) may also be connected to the bus. The bus may also link various other circuits, such as a timing source, peripherals, voltage regulators, power management circuits, and similar circuits, which are well known in the art and will not be described further herein. The processor may be implemented using one or more general-purpose processors and / or dedicated 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 overall design constraints imposed on the overall system.

[0223] If implemented in software, each function can be stored on or transmitted via a computer-readable medium as one or more instructions or code. Software should be interpreted broadly to mean instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. A computer-readable medium includes both computer storage media and communication media, including any medium that facilitates the transfer of a computer program from one place to another. A processor may be responsible for managing the bus and general processing, including executing software modules stored on a machine-readable storage medium. The computer-readable storage medium may be coupled to the processor such that the processor can read information from and write information to the storage medium. In an alternative, the storage medium may be integral with the processor. For example, the machine-readable medium may include a transmission line, a carrier modulated by data, and / or a computer-readable storage medium separate from a wireless node, all of which may be accessed by the processor via a bus interface. Alternatively or in addition, the machine-readable medium or any part thereof may be integrated into the processor, such as in the case of having a cache and / or a general register file. By way of example, examples of the machine-readable medium 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 disk drives, or any other suitable storage medium, or any combination thereof. The machine-readable medium may be embodied in a computer program product.

[0224] Software modules may include a single instruction, or many instructions, and may be distributed across several different code segments, distributed among different programs, and across multiple storage media. A computer-readable medium may include multiple software modules. Software modules include instructions that, when executed by an apparatus such as a processor, cause a processing system to perform various functions. Software modules may include a sending module and a receiving module. Each software module may reside in a single storage device or be distributed across multiple storage devices. By way of example, when a triggering event occurs, a software module may be loaded from a hard disk drive into RAM. During the execution of a software module, the processor may load some of the instructions into a cache to improve access speed. One or more cache lines may then be loaded into the general register file for the processor to execute. When referring to the functionality of a software module hereinafter, it will be understood that such functionality is implemented by the processor when executing instructions from the software module.

[0225] Additionally, any connection is properly termed a computer-readable medium. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared (IR), radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of the medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray® disc, where disks typically reproduce data magnetically, while discs reproduce data optically with a laser. Thus, in some aspects, computer-readable media can include non-transitory computer-readable media (e.g., tangible media). Additionally, for other aspects, computer-readable media can include transitory computer-readable media (e.g., signals). Combinations of the above should also be included within the scope of computer-readable media.

[0226] Accordingly, certain aspects can include a computer program product for performing the operations given herein. For example, such a computer program product can include a computer-readable medium having instructions stored (and / or encoded) thereon, the instructions (e.g., instructions for performing the operations described and Figure 8 illustrated herein) being executable by one or more processors to perform the operations described herein.

[0227] Moreover, it should be understood that modules and / or other suitable components for performing the methods and techniques described herein can be downloaded and / or otherwise obtained by a user terminal and / or a base station where applicable. For example, such devices can be coupled to a server to facilitate the transfer of components for performing 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 floppy disk) such that a user terminal and / or a base station can obtain the various methods when the storage component is coupled to or provided to the device. Additionally, any other suitable techniques for providing the methods and techniques described herein to a device can be used.

[0228] It should be understood that the claims are not limited to the exact configurations and components illustrated above. Various modifications, variations, and alterations to the arrangements, operations, and details of the methods and apparatuses described above can be made without departing from the scope of the claims.

Claims

1. A method for wireless communication by a wireless device, the method comprising: Determining a first exposure associated with a first radio for a first transmission during a first time interval; Determining a first allowable transmission power associated with a second radio for a second time interval based at least in part on the first exposure associated with the first radio; And Using the second radio to transmit a first signal at a first transmission power during the second time interval based on the first allowable transmission power.

2. The method according to claim 1, wherein: Determining the first exposure includes determining the first exposure based at least in part on a first maximum time-averaged transmission power level associated with the first radio; and Determining the first allowable transmission power includes further determining the first allowable transmission power based on a second maximum time-averaged transmission power level associated with the second radio.

3. The method according to claim 1, wherein the method further comprises: Using the first radio to transmit a second signal at a second transmission power during the second time interval, wherein the first radio has a higher transmission priority than the second radio, and the second time interval is temporally adjacent to the first time interval.

4. The method according to claim 3, wherein: The second transmission power is less than or equal to a second allowable transmission power; and The second allowable transmission power is based at least in part on an exposure margin allocated to the first radio and a first maximum time-averaged transmission power level associated with the first radio.

5. The method according to claim 4, wherein the method further comprises: Determining the second allowable transmission power based on a duty cycle associated with the first radio.

6. The method according to claim 4, wherein the exposure margin allocated to the first radio is less than or equal to one.

7. The method according to claim 1, wherein determining the first allowable transmission power is further based on a duty cycle associated with the second radio.

8. The method according to claim 1, wherein determining the first allowable transmission power includes: Determining a first exposure margin associated with the second radio based on the first exposure associated with the first radio; And Determining the first allowable transmission power based on the first exposure margin and a second maximum time-averaged transmission power level associated with the second radio.

9. The method according to claim 8, wherein determining the first allowable transmission power further includes determining the first exposure margin as the difference between one and the first exposure.

10. The method according to claim 8, wherein determining the first exposure margin includes: Determining a second exposure margin for the second radio as the difference between one and a third exposure margin allocated to the first radio; Determining an available exposure margin as the difference between the third exposure margin allocated to the first radio and the first exposure; And Determining the first exposure margin as the sum of the second exposure margin and the available exposure margin.

11. The method according to claim 10, wherein the third exposure margin allocated to the first radio is less than or equal to one.

12. The method according to claim 8, wherein determining the first allowable transmission power further comprises determining the first allowable transmission power as a product of the first exposure margin and the second maximum time-averaged transmission power level.

13. The method according to claim 8, the method further comprising: determining a second exposure margin associated with a third radio for a third time interval based on the first exposure margin and a second exposure associated with the second radio used for a second transmission during the second time interval; determining a second allowable transmission power associated with the third radio for the third time interval based on the second exposure margin and a second maximum time-averaged transmission power level associated with the third radio; and transmitting a second signal at a second transmission power using the third radio during the third time interval based on the second allowable transmission power.

14. The method according to claim 13, wherein determining the second exposure margin comprises: determining a third exposure margin for the third radio as a difference between a sum of a minimum exposure margin assigned to the first radio and a minimum exposure margin assigned to the second radio; determining an available exposure margin as a difference between the first exposure margin assigned to the second radio and the second exposure; and determining the second exposure margin as a sum of the third exposure margin for the third radio and the available exposure margin.

15. The method according to claim 13, wherein the third time interval has the same duration as the second time interval.

16. The method according to claim 13, the method further comprising: transmitting a third signal using the first radio during the third time interval; and transmitting a fourth signal using the second radio during the third time interval, wherein the third time interval is adjacent in time to the second time interval, and wherein the second time interval is between the first time interval and the third time interval in time.

17. The method according to claim 13, wherein determining the second allowable transmission power comprises further determining the second allowable transmission power based on a duty cycle associated with the third radio.

18. The method according to claim 13, wherein determining the second allowable transmission power comprises further determining the second allowable transmission power based on a second power limit applied to the second radio.

19. The method according to claim 1, wherein determining the first allowable transmission power comprises further determining the first allowable transmission power based on a first power limit applied to the first radio.

20. The method according to claim 1, wherein the method further comprises: Determining a second allowable transmission power associated with a third radio, the third radio being associated with a first antenna group, wherein the first radio and the second radio are associated with a second antenna group.

21. The method according to claim 20, wherein the determination of the second allowable transmission power is independent of transmissions associated with the second antenna group.

22. The method according to claim 1, wherein the method further comprises: Use the first radio to transmit a second signal in a sub - 6 GHz band, where transmitting the first signal includes using the second radio to transmit the first signal in a mmWave band.

23. The method according to claim 1, the method further comprising: Select the first radio among the radios based on one or more priorities associated with the multiple radios.

24. An apparatus for wireless communication, the apparatus comprising: One or more memories that jointly store executable instructions; And One or more processors coupled to the one or more memories, the one or more processors being jointly configured to execute the executable instructions to cause the apparatus to: Determine a first exposure associated with a first radio used for a first transmission during a first time interval; Determine a first allowable transmit power associated with a second radio for a second time interval based at least in part on the first exposure associated with the first radio; And Control the use of the second radio to transmit a first signal at a first transmit power during the second time interval based on the first allowable transmit power.

25. The apparatus according to claim 24, wherein: To determine the first exposure, the one or more processors are jointly configured to execute the executable instructions to cause the apparatus to determine the first exposure based at least in part on a first maximum time - averaged transmit power level associated with the first radio; and To determine the first allowable transmit power, the one or more processors are jointly configured to execute the executable instructions to cause the apparatus to further determine the first allowable transmit power based on a second maximum time - averaged transmit power level associated with the second radio.

26. The apparatus according to claim 24, wherein: The one or more processors are further jointly configured to execute the executable instructions to cause the apparatus to use the first radio to transmit a second signal at a second transmit power during the second time interval; The first radio has a higher transmit priority than the second radio; And The second time interval is adjacent in time to the first time interval.

27. The apparatus according to claim 26, wherein: The second transmit power is less than or equal to a second allowable transmit power; and The second allowable transmit power is at least in part based on an exposure margin allocated to the first radio and a first maximum time - averaged transmit power level associated with the first radio.

28. The apparatus according to claim 27, wherein the one or more processors are further jointly configured to execute the executable instructions to cause the apparatus to determine the second allowable transmit power based on a duty cycle associated with the first radio.

29. An apparatus for wireless communication, the apparatus comprising: Means for determining a first exposure associated with a first radio used for a first transmission during a first time interval; A component for determining a first allowable transmit power associated with a second radio for a second time interval based at least in part on the first exposure associated with the first radio; and A component for using the second radio to transmit a first signal at a first transmit power during the second time interval based on the first allowable transmit power.

30. A non-transitory computer-readable medium having instructions stored thereon that, when executed by a device, cause the device to perform operations, the operations including: Determining a first exposure associated with a first radio used for a first transmission during a first time interval; Determining a first allowable transmit power associated with a second radio for a second time interval based at least in part on the first exposure associated with the first radio; and Using the second radio to transmit a first signal at a first transmit power during the second time interval based on the first allowable transmit power.

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