Devices and methods for controlling exposure to wireless communications

Abstract

A signal processing device for controlling exposure to wireless communication, the signal processing device (150; 250; 650; 650', 850) comprising: a processing circuit (251; 851) which is arranged to determine at least one distance between an external object based on at least one reflection coefficient, and to control a transmission by a first antenna module (111, 112; 300; 500; 700) based on the at least one determined distance, wherein the at least one reflection coefficient includes a reflection coefficient of a second antenna module (121, 122; 621; 621'), wherein the first antenna module (111, 112; 300; 500; 700) is configured for wireless communication in a first frequency band, the second antenna module (121, 122; 621; 621') is configured for wireless communication in a second frequency band, and the second frequency band is a lower frequency band than the first frequency band.

Description

background

[0001] The inventive concepts relate to wireless communication and, more particularly, to an apparatus and method for controlling exposure of a user to electromagnetic waves used for wireless communication.

[0002] Signal transmission in a wireless communication system may be susceptible to path loss, fading due to shadowing, etc., and therefore, high transmission power may be used to prevent or reduce the degradation of the quality of service (QoS) of wireless communication. In particular, high transmission power may be used in wireless communication that uses a signal of a high frequency band that is easily attenuated, such as a millimeter wave (mmWave) band. However, as the transmission power increases, heat generation in a wireless communication device may increase. Also, as the transmission power increases, high-density electromagnetic waves may be generated during transmission. Therefore, it is desirable to reduce the energy consumed by a user of a wireless communication device, e.g., a mobile phone.a terminal device, due to which electromagnetic waves are absorbed.

[0003] US 2018 / 0 287 259 A1 discloses the following: An antenna device, a wireless communication device, and a method for providing broadband antenna tuning are disclosed. The antenna device is configured to include an antenna element for a higher frequency range, an antenna element for a lower frequency range, a resonant switch, and coupler elements for a high and a lower frequency range. The antenna device provides a high-frequency switching stage and a low-frequency switching stage. The high-frequency switching stage includes the antenna device configured to resonate at one or more frequencies within a high-impedance bandwidth, and the low-frequency switching stage includes the antenna device configured to resonate at one or more frequencies within a low-impedance bandwidth.The antenna device further includes an impedance tuning circuit for modifying the impedance bandwidths of both the low and high frequency bandwidths. The antenna device is configured to perform impedance tuning separately for a transmit signal and a receive signal. Summary

[0004] The inventive concepts provide a method and apparatus for effectively reducing a user's exposure to electromagnetic waves while maintaining the quality of wireless communication.

[0005] The scope of the invention is defined by the appended claims.

[0006] According to one aspect of the inventive concepts, a signal processing device for controlling exposure to wireless communication is provided, the signal processing device comprising a processing circuit configured to control transmission by a first antenna module based on a reflection coefficient of a second antenna module, the first antenna module being configured for wireless communication in a first frequency band, the second antenna module being configured for wireless communication in a second frequency band, the second frequency band being a lower frequency band than the first frequency band.

[0007] According to one aspect of the inventive concepts, a signal processing device is provided for controlling exposure to wireless communication, the signal processing device comprising a processing circuit configured to receive a plurality of power levels from a plurality of first antenna modules, the plurality of first antenna modules configured for wireless communication in a first frequency band, each respective first antenna module of the plurality of first antenna modules comprising a respective antenna and a respective power sensor configured to detect a respective power level of a signal received via the respective antenna, the respective power level being one of a plurality of power levels, and to reduce a transmission power output by a low-power first antenna module of the plurality of first antenna modules,if a difference between a lowest power level of the plurality of power levels and a second lowest power level of the plurality of power levels is greater than a first reference value, wherein the first low-power antenna module corresponds to the lowest power level.

[0008] According to one aspect of the inventive concepts, a terminal device capable of connecting to a plurality of wireless communication systems is provided, the terminal device comprising a plurality of first antenna modules configured to connect to a first wireless communication system using a first frequency band, a plurality of second antenna modules configured to connect to a second wireless communication system using a second frequency band, the second frequency band being a lower frequency band than the first frequency band, and a processing circuit configured to calculate a plurality of calculated reflection coefficients of the plurality of second antenna modules and to control transmission by the plurality of first antenna modules based on the plurality of calculated reflection coefficients.

[0009] According to one aspect of the inventive concepts, a method for controlling exposure to millimeter wave (mmWave) wireless communication is provided, the method comprising: calculating a plurality of calculated reflection coefficients of a plurality of second antenna modules configured to connect to a low-band wireless communication system using a frequency band lower than a millimeter wave frequency band; determining a plurality of determined distances between an external object and a plurality of first antenna modules based on the plurality of calculated reflection coefficients, wherein the plurality of first antenna modules are configured to connect to a millimeter wave wireless communication system using millimeter waves;and controlling transmission by the plurality of first antenna modules based on the plurality of determined distances; Short description of the drawings

[0010] Embodiments of the inventive concepts will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings.

[0011] The accompanying drawings may not be to scale for ease of illustration and may be excessively enlarged or reduced. Fig. 1 is a block diagram illustrating wireless communication systems including a communication device according to an embodiment of the inventive concepts; Fig. 2 is a block diagram showing a user equipment (UE) according to an embodiment of the inventive concepts; Fig. 3 is a flowchart of a method for controlling exposure to wireless communication according to an embodiment of the inventive concepts; Fig. 4 is a schematic perspective view of a UE according to an embodiment of the inventive concepts; Fig. 5 is a graph showing examples of reflection coefficients of a second antenna module according to an embodiment of the inventive concepts; Fig. 6 is a block diagram showing a UE including a lookup table according to an embodiment of the inventive concepts; Fig. 7 is a diagram showing an example of a lookup table included in a UE according to an embodiment of the inventive concepts; Fig. 8 is a block diagram showing a UE including an artificial neural network according to an embodiment of the inventive concepts; Fig. Figure 9 is a flowchart showing an example of operation S30 from Fig. 3 according to an embodiment of the inventive concepts; Fig. 10 is a block diagram showing a UE including a controller configured to receive a status signal S_STA according to an embodiment of the inventive concepts; Fig. 11 is a block diagram showing a first antenna module including a power detection device according to an embodiment of the inventive concepts; Fig. 12 is a flowchart of a method for controlling exposure to wireless communication by controlling transmission of a plurality of first antenna modules comprising the first antenna module of Fig. 11, according to an embodiment of the inventive concepts; Fig. 13 is a flowchart showing an example of operation S50 from Fig. 12 according to an embodiment of the inventive concepts; Fig. 14 is a block diagram showing a first antenna module including a temperature sensor according to an embodiment of the inventive concepts; Fig. 15 is a flowchart of a method for controlling exposure to wireless communication by controlling transmission of a plurality of first antenna modules comprising the first antenna module of Fig. 14, according to an embodiment of the inventive concepts; Fig. 16 is a block diagram showing a first antenna module including a data processor according to an embodiment of the inventive concepts; and Fig. 17 is a block diagram showing a communication device according to an embodiment of the inventive concepts. Detailed description

[0012] Fig. Figure 1 is a block diagram showing wireless communication systems including a communication device according to an embodiment of the inventive concepts. In detail, Fig. 1 a user equipment (UE) 100 as a wireless communication device that supports a plurality of wireless communication systems, such as a first wireless communication system RAT1 and a second wireless communication system RAT2.

[0013] A wireless communication system may include, but is not limited to, a wireless communication system using a cellular network, such as a fifth-generation (5G) wireless system, a Long Term Evolution (LTE) system, an LTE Advanced system, a Code Division Multiple Access (CDMA) system, a Global System for Mobile Communications (GSM) system, a Wireless Local Area Network (WLAN) system, and / or any other wireless communication system. Below, a wireless communication system will be described primarily with reference to a wireless communication system using a cellular network, but it should be understood that exemplary embodiments are not limited thereto.

[0014] The UE 100 may be connected to the first wireless communication system RAT1 and the second wireless communication system RAT2, which may be different from each other, and the first wireless communication system RAT1 may use a higher frequency band than the second wireless communication system RAT2. For example, the first wireless communication system RAT1 (e.g., a millimeter-wave wireless communication system) may be a wireless communication system that uses millimeter waves (mmWave) (e.g., a 5G system), whereas the second wireless communication system RAT2 (e.g., a low-frequency band wireless communication system) may be a wireless communication system that uses a frequency band lower than millimeter waves (mmWave) (e.g., an LTE system). The second wireless communication system RAT2 may also be referred to as a legacy wireless communication system. As in Fig. 1, the UE 100 may communicate with a first base station 10 in a first wireless communication system RAT1 and communicate with a second base station 20 in the second wireless communication system RAT2. In some embodiments that differ from the embodiment shown in Fig. 1, the UE 100 may communicate with a base station according to one or two different communication systems (e.g., via the first wireless communication system RAT1 and the second wireless communication system RAT2). Also, in some embodiments, the UE 100 may support connections to three or more different wireless communication systems.

[0015] A base station BS, such as the first base station 10 and the second base station 20, may generally refer to a fixed station that communicates with a UE and / or other base stations, and may exchange data and / or control information by communicating with the UE and / or the other base stations. For example, a base station may be referred to as a Node B, evolved Node B (eNB), next-generation Node B (gNB), sector, site, Base Transceiver System (BTS), access point (AP), switching node, remote radio head (RRH), radio unit (RU), small cell, etc.In this specification, base station or cell can be understood as a comprehensive term that refers to a part and / or function covered by a Base Station Controller (BSC) in CDMA, a Node-B in WCDMA, an eNB in ​​LTE, a gNB in ​​5G and / or a sector (site), and can include different coverage areas such as a megacell, a macrocell, a microcell, a picocell, a femtocell, an RRH, a RU and / or a small cell communication range.

[0016] The UE 100 may refer to any device that is stationary or mobile and may communicate with a base station, e.g., the first base station 10 and / or the second base station 20, to transmit and / or receive data and / or control information. For example, the UE 100 may be referred to as a terminal equipment, terminal equipment, mobile station (MS), mobile terminal (MT), user terminal (UT), subscriber station, wireless device, portable device, etc. In the following, exemplary embodiments are described primarily with reference to the UE 100 as a wireless communication device, but it should be understood that exemplary embodiments are not limited thereto.

[0017] A wireless communication network between the UE 100 and the first base station 10 or the second base station 20 can support communication between a plurality of users by sharing available network resources. For example, in a wireless communication network, information can be transmitted using different multiplexing types, such as Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), OFDM-FDMA, n OFDM-TDMA, and / or OFDM-CDMA. As described in Fig. As shown in Figure 1, the UE 100 may communicate with the first base station 10 and / or the second base station 20 via an uplink and / or a downlink. In some embodiments, UEs may communicate with each other via a sidelink, e.g., Device-to-Device (D2D). For example, the UE 100 may communicate with another UE via a sidelink.

[0018] The UE 100 may include a plurality of first antenna modules 111 and 112 and a plurality of second antenna modules 121 and 122 as shown in Fig. 1. Each of the first antenna modules 111 and 112 and the second antenna modules 121 and 122 may include at least one antenna and process signals received via the antenna and / or signals to be transmitted via the antenna. For example, each of the first antenna modules 111 and 112 and the second antenna modules 121 and 122 may include a front-end radio frequency integrated circuit (RFIC) and may, as described below with reference to Fig. 11, a power amplifier, a low-noise amplifier, a mixer, an RF switch, etc. The first antenna modules 111 and 112 may be used by the UE 100 to connect to the first wireless communication system RAT1, whereas the second antenna modules 121 and 122 may be used by the UE 100 to connect to the second wireless communication system RAT2. Furthermore, to enable communication with base stations, i.e., the first base station 10 and / or the second base station 20, despite transmission and / or reception interference by antenna modules due to an obstacle such as a user's body part and / or an orientation of the UE 100, the first antenna modules 111 and 112 and the second antenna modules 121 and 122 may be arranged separately from (e.g., external to and / or remote from) the UE 100. In some embodiments, unlike in Fig. 1, the UE 100 may include three or more first antenna modules and may include three or more second antenna modules.

[0019] The UE 100 may include a signal processor 150. The signal processor 150 may communicate with the first antenna modules 111 and 112 and / or the second antenna modules 121 and 122. For example, the signal processor 150 may communicate with the first base station 10 through at least one of the first antenna modules 111 and 112 and / or it may communicate with the second base station 20 through at least one of the second antenna modules 121 and 122. The signal processor 150 may be referred to as a signal processing device, and the signal processor 150 may, as in Fig. 1, include a controller 155.

[0020] In a high frequency band, such as a millimeter wave (mmWave) band, a shortwave signal may have a strong straightness that can be easily attenuated by an obstacle, and therefore, a signal may provide a varying reception ratio depending on the orientation of an antenna. Therefore, in a wireless communication system that uses a high frequency band, to increase throughput, a transmitter may use high transmission power. For example, the first antenna modules 111 and 112 for connecting to the first wireless communication system RAT1, which uses a relatively high frequency band, may use higher transmission power than the second antenna modules 121 and 122, and therefore, a user of the UE 100 may be exposed to the electromagnetic waves generated by the first antenna modules 111 and 112.Metrics such as a specific absorption rate (SAR) and / or maximum acceptable exposure (MAA) can be used to measure energy absorbed by a human body due to electromagnetic waves, and authorities such as the Federal Communications Commission (FFC) of the United States of America define values ​​that wireless communication devices must adhere to. Therefore, it may be desirable for a wireless communication device, such as a UE 100, to limit or reduce a user's exposure to electromagnetic waves while maintaining the quality of wireless communication with the base station, e.g., the first base station 10.

[0021] The controller 155 may determine a relative location of an external object, e.g., a user, with respect to the UE 100 and may control a transmission power of the first antenna modules 111 and 112 based on a determined location, thereby controlling a user's exposure to electromagnetic waves. In some embodiments, the controller 155 may calculate reflection coefficients of the second antenna modules 121 and 122 included in the UE 100 for connection to the second wireless communication system RAT2, which is a legacy wireless communication system, and determine a relative location of an external object with respect to the UE 100 based on the reflection coefficients.In some embodiments, the controller 155 may obtain information regarding a received power from each of the first antenna modules 111 and 112 and determine a relative location of an external object with respect to the UE 100 based on the received power. Furthermore, in some embodiments, the controller 155 may obtain a temperature from each of the first antenna modules 111 and 112 and may limit a transmitted power by the first antenna modules 111 and 112 based on temperatures. According to some example embodiments, operations described herein as being performed by the UE 100, the signal processor 150, and / or the controller 155 may be performed by a processing circuit.The term "processing circuitry" as used in the present disclosure may refer, for example, to hardware that includes logic circuitry, a hardware / software combination such as a processor that executes software, or a combination thereof. For example, the processing circuitry may specifically include, but is not limited to, a central processing unit (CPU), an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a system on chip (SoC), a programmable logic unit, a microprocessor, an application-specific integrated circuit (ASIC), etc.For example, in some embodiments, the controller 155 may include a hardware logic block configured by logic synthesis or the like, and may include a software block and at least one processing core to execute the software block.

[0022] Fig. 2 is a block diagram showing a UE 200 according to an embodiment of the inventive concepts, and Fig. Figure 3 is a flowchart of a method for controlling exposure to wireless communication according to an embodiment of the inventive concepts. In some embodiments, the method may be Fig. 3 from a UE 200 (or a Controller 255) Fig. 2. Below, Fig. 2 and Fig. 3 with reference to Fig. 1 described.

[0023] In Fig. 2, the UE 200 may include a plurality of first antenna modules 210, a plurality of second antenna modules 220, and / or a signal processor 250. As described above with reference to Fig. As described in Figure 1, the first antenna modules 210 may be used to connect to the first wireless communication system RAT1 using a relatively high frequency band, whereas the second antenna modules 220 may be used to connect to the second wireless communication system RAT2 using a relatively low frequency band. Below, it is assumed that the UE 200 comprises N first antenna modules and M second antenna modules (M and N are integers greater than 1).

[0024] The signal processor 250 may include a first processing circuit 251, a second processing circuit 252 and / or the controller 255, as shown in Fig. 2. The first processing circuit 251 may communicate with the first antenna modules 210, and / or the second processing circuit 252 may communicate with the second antenna modules 220. According to some example embodiments, operations described herein as being performed by the UE 200, the signal processor 250, the first processing circuit 251, the second processing circuit 252, and / or the controller 255 may be performed by a processing circuit. For example, the first processing circuit 251 and the second processing circuit 252 may be referred to as an RFIC and / or a back-end RFIC and may communicate with the first antenna modules 210 and the second antenna modules 220 via signals in an RF band and / or an intermediate frequency (IF) band.The first processing circuit 251 and the second processing circuit 252 may each include a mixer, a filter, an amplifier, and / or the like. The controller 255 may receive feedforward signals S_FC and / or feedforward signals S_RC from the second antenna modules 220 and generate a control signal C_TX for controlling a transmission power by the first antenna modules 210.

[0025] In Fig. 3, a process for calculating reflection coefficients of the second antenna modules 220 may be performed in process S10. For example, the controller 255 may calculate reflection coefficients of antennas included in the second antenna modules 220 based on the feedforward signals S_FC and the reverse feedback signals S_RC received from the second antenna modules 220. In the present specification, the reflection coefficient (or impedance) of an antenna may be referred to as the reflection coefficient (or impedance) of an antenna module including the corresponding antenna. As described below with reference to Fig. 6, the second antenna modules 220 may include bidirectional couplers, and the bidirectional couplers may provide the feedforward signals S_FC to the controller 255 by coupling signals provided to the second antenna modules 220 by the second processing circuit 252. The bidirectional couplers may also provide the reverse coupling signals S_RC to the controller 255 by coupling signals reflected and returned from antennas included in the second antenna modules 220. The controller 255 may calculate impedances of current antennas from pairs of the feedforward signals S_FC and the reverse coupling signals S_RC that correspond to each other, and the calculated impedances of the antennas may be used for antenna impedance tuning (AIT). For example, a reflection coefficient Γ can be calculated as shown in Equation 1 below. Γ=|rrev||rfwd|⋅exp(j( <rre−<rfwd))

[0026] In equation 1, r denotes fwd a signal obtained by feedforward coupling, and r rev denotes a signal obtained by feedback. The controller 255 may calculate reflection coefficients of current antennas based on current impedances of the antennas and a design impedance of the antennas. In some embodiments, the reflection coefficient of an antenna may be calculated based on a standing wave (SW) ratio. According to some example embodiments, the designed impedance of the antennas may refer to a design parameter determined through empirical testing.

[0027] In operation S20, an operation for determining distances between the first antenna modules 210 and an external target may be performed. As described above with reference to Fig. 1, the second antenna modules 220 may be arranged separately from the UE 200 and, as described below with reference to Fig. 4 and Fig. 5, the reflection coefficients of antennas included in the second antenna modules 220 may vary depending on relative locations of an external object with respect to the UE 200. Therefore, the controller 255 may detect a relative position of an external object with respect to the UE 200 based on patterns of the reflection coefficients of the second antenna modules 220 calculated in operation S10 and determine distances between the first antenna modules 210 and the external object. An example of operation S20 is described below with reference to Fig. 6 and Fig. 7 described.

[0028] In operation S30, an operation for controlling transmissions by the first antenna modules 210 may be performed. For example, the controller 255 may control transmissions by the first antenna modules 210 based on distances determined in operation S20. For example, the controller 255 may reduce a transmission power by a first antenna module of the first antenna modules 210 that is determined to be close to the external object. The controller 255 may increase a transmission power by a first antenna module of the first antenna modules 210 that is determined to be far from the external object. Accordingly, exposure of an external object, e.g., a user, to electromagnetic waves may be reduced without degrading the quality of the wireless communication. An example of operation S30 is described below with reference to Fig. 9 described.

[0029] Fig. 4 is a perspective view schematically showing the UE 400 according to an embodiment of the inventive concepts, and Fig. 5 is a graph showing examples of reflection coefficients of second antenna modules according to an embodiment of the inventive concepts.

[0030] In Fig. 4, the UE 400 may include a first antenna module 410. The first antenna module 410 may transmit and / or receive signals of a radio frequency band, such as a millimeter wave (mmWave) band, and may, as shown in Fig. 4, may comprise at least one patch antenna that may form a beam (e.g., a front-side beam) toward a front side of the UE 400, i.e., a surface perpendicular to the Z-axis, and / or may comprise at least one diplo-antenna that may form a beam (e.g., a longitudinal beam) toward a side surface of the UE 400, i.e., a surface perpendicular to the X-axis. Although in Fig. 4 only the first antenna module 410 is shown for ease of illustration, the UE 400 may comprise a plurality of first antenna modules as described above with reference to the figures.

[0031] The UE 400 may include a plurality of second antenna modules 421 and 422. As shown in Fig. 4, the second antenna module 421 comprising a primary antenna may be placed at one end of the UE 400, that is, at an end in the -X axis direction, whereas the second antenna module 422 comprising a diversity antenna may be placed at another end, that is, at an end in the +X axis direction.

[0032] In Fig. 5, when there is no external object near the second antenna module 422, the impedance of the second antenna module 422 may be a design impedance, e.g., 50 Ω, and therefore the reflection coefficient of the second antenna module 422 in the polar coordinates may be Fig. 5 correspond to the center point. On the other hand, when an external object is located near the front surface of the UE 400, the reflection coefficient of the second antenna module 422 in the polar coordinates (e.g., the impedance polar diagram) can be Fig. 5 to the bottom left. When an external object is located near a side surface of the UE 400, the reflection coefficient of the second antenna module 422 in the polar coordinates can be Fig. 5 to the bottom right. In this regard, the reflection coefficients of the plurality of second antenna modules 421 and 422 may vary according to relative locations of the external object with respect to the UE 400, and thus the location of the external object may be determined. Fig. Figure 5 shows an example where the reflection coefficient varies, and it should be understood that in some embodiments the reflection coefficient may vary differently depending on the location of the external object than in Fig. 5 shown manner.

[0033] Fig. Figure 6 is a block diagram showing a UE 600 according to an embodiment of the inventive concepts. In particular, Fig. 6 a signal processor 650 as an example of the signal processor 250 from Fig. 2 and a second antenna module 621 as an example of one of a plurality of second antenna modules. A description will be omitted below that is inconsistent with the above-mentioned with reference to Fig. 2 is identical or similar to the given one.

[0034] In Fig. 6, the signal processor 650 may include a second processing circuit 652, a controller 655, and / or a lookup table 657. The second processing circuit 652 may communicate with the second antenna module 621. The controller 655 may receive a feedforward signal S_FC1 and a feedforward signal S_RC1 from the second antenna module 621 and generate a control signal C_TX for controlling a transmission power by a plurality of first antenna modules (e.g., 210 of Fig. 2) generate by reference to information stored in the lookup table 657. For example, the controller 655 may determine a plurality of calculated reflection coefficients of the plurality of second antenna modules, obtain a plurality of obtained distances to the external object based on the calculated reflection coefficients by referring to the information stored in the lookup table 657 (e.g., by determining a plurality of distances associated with the combination represented by the calculated reflection coefficients), and generate the control signal C_TX based on the obtained distances to the external object. According to some example embodiments, operations described herein as being performed by the UE 600, the signal processor 650, the second processing circuit 652, and / or the controller 655 may be performed by a processing circuit.

[0035] The second antenna module 621 may include a power amplifier 61, a coupler 62, and / or an antenna 63. The coupler 62 includes a bidirectional coupler (e.g., it may be one) and, during a transmission time, may provide the feedforward coupling signal S_FC1 to the controller 655 by feeding forward, i.e., by coupling (e.g., outputting) signals transmitted from the power amplifier 61 to the antenna 63, and may provide the reverse coupling signal S_RC1 to the controller 655 by feeding back, i.e., by coupling (e.g., outputting) signals reflected from the antenna 63. In some embodiments, the coupler 62 may be included in the second antenna module 621 to tune the impedance of the antenna 63 (e.g.,it can be used for this purpose), and the coupler 62 can be used by the controller 655, as described above with reference to the drawings, to detect a relative location of an external object with respect to the UE 600. Therefore, without additional components such as a proximity sensor, a gyro sensor, a touch sensor, etc., a distance between the UE 600 and an external object can be determined, and therefore the UE 600 can be highly cost and / or space efficient.

[0036] The lookup table 657 may include combinations of reflection coefficients (e.g., reference reflection coefficients) of a plurality of second antenna modules comprising the second antenna module 621 and information regarding locations of an external object corresponding to the respective combinations (e.g., reference distances). Therefore, the controller 655 may access the lookup table 657 and acquire a location of an external object corresponding to the reflection coefficients determined based on feedforward signals (e.g., S_FC from Fig. 2), which include the feedforward signal S_FC1, and feedback signals (e.g. S_RC from Fig. 2) comprising the feedback signal S_RC1. The lookup table 657 may comprise a memory (e.g., stored on a memory and / or forming a memory and / or a data structure), and information (e.g., the information comprised in the lookup table 657) may be stored on the memory when the UE 600 and / or the signal processor 650 are manufactured. For example, the lookup table 657 may comprise non-volatile memory and may include, but is not limited to, an electrically erasable read-only memory (EEPROM), a flash memory, a phase-change random access memory (PRAM), a resistive random access memory (RRAM), a nano-floating gate memory (NFGM), a polymer random access memory (PoRAM), a magnetic random access memory (MRAM), and / or a ferroelectric random access memory (FRAM).An example of the lookup table 657 is given below with reference to . Fig. 7 described.

[0037] Fig. Fig. 7 is a diagram showing an example of a lookup table included in a UE according to an embodiment of the inventive concepts. In detail, a lookup table 657' may be Fig. 7 an example of the lookup table 657 from Fig. 6. As mentioned above with reference to Fig. 6, the lookup table 657' may include combinations of reflection coefficients of a plurality of second antenna modules and information regarding locations of an external target corresponding to the respective combinations. Fig. 7 with reference to Fig. 6 described.

[0038] In some embodiments, the lookup table 657' may include distances (e.g., reference distances) between a plurality of first antenna modules (e.g., the plurality of first antenna modules 210) to the external object as locations of the external object, which respectively correspond to the combinations of the reflection coefficients of the second antenna modules. For example, as in Fig. 7, the lookup table 657' K combinations C1 to C K (K is an integer greater than 1) as combinations of values ​​(e.g. r 11 to r KM ) of M reflection coefficients R1 to R M (e.g. reference reflection coefficients) obtained from M second antenna modules (e.g. each coefficient R1 to R Mobtained from another second antenna module of the M second antenna modules). In some embodiments, the values ​​of the reflection coefficients included in the lookup table 657' may indicate the range of reflection coefficients (e.g., the full range of possible and / or predicted reflection coefficients). Accordingly, the lookup table 657' includes values ​​(e.g., D 11 to D KN ) from N distances D1 to D N between N first antenna modules and the external object, each corresponding to the K combinations C1 to C K correspond (e.g. each distance D1 to D Nmay represent a distance from another first antenna module of the N first antenna modules). In some embodiments, the values ​​of distances included in the lookup table 657' may indicate the range of distances, and may indicate a degree of distance from the external object, e.g., very close, near, or far.

[0039] Fig. Figure 8 is a block diagram showing a UE 600' according to an embodiment of the inventive concepts. In particular, Fig. 8 a signal processor 650' as an example of the signal processor 650 from Fig. 6 and a second antenna module 621' as an example of one of a plurality of second antenna modules (e.g., the plurality of second antenna modules 220). The following description is omitted which is identical to the one described above with reference to Fig. 6 is identical or similar to the given one.

[0040] In Fig. 8, the signal processor 650' may include a second processing circuit 652', a controller 655', and / or an artificial neural network (ANN) 658. Also, the second antenna module 621' may include a power amplifier 61', a coupler 62', and / or an antenna 63', and may provide the feedforward signal S_FC1 and the reverse signal S_RC1 to the controller 655'. Compared to the signal processor 650 of Fig. 6, the signal processor 650' can be Fig. 8 may include the ANN 658 instead of the lookup table 657. According to some example embodiments, operations described herein as being performed by the UE 600', the signal processor 650', the second processing circuit 652', the controller 655', and / or the ANN 658' may be performed by a processing circuit.

[0041] The ANN 658 may receive reflection coefficients R from a plurality of second antenna modules comprising the second antenna module 621' from the controller 655, and distances D between a plurality of first antenna modules (e.g., 210 of Fig. 2) and an external object in response to the reflection coefficients R. The ANN 658 may refer to a structure (e.g., a trained feature vector) in which sets of artificial neurons (or neuron models) are interconnected. An artificial neuron may generate output data by performing simple operations on input data, and the output data may be transmitted to other artificial neurons. The ANN 658 may be trained with the reflection coefficients (e.g., reference reflection coefficients) of a plurality of second antenna modules (e.g., a plurality of second reference antenna modules), and therefore, the ANN 658 may output the distances D in response to the reflection coefficients R provided by the controller 655'.

[0042] Fig. Figure 9 is a flowchart showing an example of operation S30 from Fig. 3 according to an embodiment of the inventive concepts. As described above with reference to Fig. 3, a process for controlling transmissions by a plurality of first antenna modules (e.g., 210 of Fig. 2) in process S30' from Fig. 9. In detail, Fig. 9 a method for controlling a transmission by a particular first antenna module of the N first antenna modules based on a distance d i between the determined first antenna module (1 ≤ i ≤ N) and an external object, and process S30' from Fig. 9 can be repeated for each of the first N antenna modules. As in Fig. 9, operation S30' may include a plurality of operations S31, S33, S35, S37 and S39, and in some embodiments, operation S30' may be Fig. 9 from the controller 255 Fig. 2. The following Fig. 9 with reference to Fig. 2 described.

[0043] According to Fig. 9, in operation S31, an operation for comparing the distance d i with a first distance D1. The first distance D1 may be smaller than a second distance D2 described below and may have a small value (e.g., 5 mm or 10 mm) to determine a condition that an external object is very close to a first antenna module. If the distance d i is smaller than the first distance D1, it can therefore be determined that the external object is very close to the first antenna module. As shown in Fig. 9, if the distance d i is smaller than the first distance D1, then operation S33 must be carried out. If the distance d i is not smaller than the first distance D1, operation S37 can then be carried out.

[0044] If it is determined in operation S31 that the distance d iis smaller than the first distance D1, a process for reducing the transmission power of a first antenna module according to the distance d i (e.g., the determined first antenna module) in operation S33. For example, the controller 255 may, based on the distance d i is smaller than the first distance D1, determine that the external object is very close to the first antenna module according to the distance d i and therefore, the controller 255 may reduce the transmission power of the corresponding first antenna module or deactivate the corresponding first antenna module by the control signal C_TX to reduce the energy absorption of the external object by electromagnetic waves.

[0045] In operation S35, an operation for increasing the transmission power of at least one antenna module according to a desirable distance (e.g., a first antenna module different from the first antenna module corresponding to the distance d icorresponds,). For example, the controller 255 may increase the transmission power of at least one first antenna module among a plurality of first antenna modules, wherein the at least one antenna module is spaced a desirable distance from the external object by the control signal C_TX. The desirable distance may refer to a distance at which no external object is detected or the influence on an external object is small. In some embodiments, the desirable distance may be defined as a distance greater than the first distance D1 and a second distance D2. Therefore, the transmission power by the first antenna module near the external object may be reduced in operation S33, while the transmission power by at least one first antenna module located far from the external object may be increased in operation S35.Therefore, a user's exposure to electromagnetic waves can be reduced while maintaining wireless communication quality.

[0046] If it is determined in operation S31 that the distance d i is not smaller than the first distance D1, an operation to compare the distance d i with the second distance D2 in operation S37. The second distance D2 may be greater than the first distance D1 and may have a value (e.g., 50 mm or 100 mm) to determine a condition according to which the external object is close to, but not very close to, the first antenna module. If the distance d i is smaller than the second distance D2, therefore the distance d i between the first distance D1 and the second distance D2, and it can be determined that the external object is close to the antenna module. As in Fig. 9, if the distance d i is smaller than the second distance D2, then operation S39 must be performed. If the distance d i is not smaller than the second distance D2, the process S30' may be repeated with respect to the first antenna module and / or another first antenna module of the plurality of first antenna modules.

[0047] If it is determined in operation S37 that the distance d i is smaller than the second distance D2, an operation for extending the beam width of a first antenna module according to the distance d i in operation S39. For example, the controller 255 may adjust the beam width emitted by the first antenna module according to the distance d iformed via the control signal C_TX, and thus the energy density absorbed by a user can be reduced. According to some exemplary embodiments, the first distance D1 and / or the second distance D2 may be design parameters determined through empirical studies.

[0048] Fig. 10 is a block diagram showing a UE 800 according to an embodiment of the inventive concepts. In Fig. 10, the UE 800 may include first antenna modules 810, second antenna modules 820, and / or a signal processor 850, and the signal processor 850 may include a first processing circuit 851, a second processing circuit 852, and / or a controller 855. Hereinafter, descriptions that are similar to those described above with reference to Fig. 2 are identical or similar to those given. According to some example embodiments, operations described herein as being performed by the UE 800, the signal processor 850, the first processing circuit 851, the second processing circuit 852, and / or the controller 855 may be performed by a processing circuit.

[0049] The controller 855 may receive a status signal S_STA indicating the states of a plurality of first antenna modules 810 and may generate a control signal C_TX to control the transmission power(s) via the first antenna modules 810 based on the status signal S_STA. Although in Fig. 10, the controller 855 may, in some embodiments, select the feedforward signals S_FC and the feedback signals S_RC from Fig. 2 from a plurality of second antenna modules 820 and receive the control signal C_TX based on the feedforward signals S_FC and the feedforward signals S_RC together with the status signal S_STA.

[0050] In some embodiments, the controller 855 may, as described below with reference to Fig. 11 and Fig. 12, the controller 855 may receive the status signal S_STA, which includes information regarding a received power detected by the first antenna modules 810, and may generate the control signal C_TX based on the received power of the first antenna modules 810. Also, in some embodiments, as described below with reference to Fig. 13 and Fig. 14, receive the status signal S_STA, which includes information regarding temperatures of the first antenna modules 810, and may generate the control signal C_TX based on the temperatures of the first antenna modules 810.

[0051] Fig. 11 is a block diagram showing a first antenna module 300 according to an embodiment of the inventive concepts, and Fig. 12 is a flowchart of a method for controlling exposure to wireless communication according to an embodiment of the inventive concepts. In detail, the first antenna module 300 may be Fig. 11 an example of one of the first antenna modules 810 from Fig. 10, and the procedure from Fig. 12 is a method for transmission control of a plurality of first antenna modules comprising the first antenna module 300 of Fig. 11. In some embodiments, the method of Fig. 12 from the controller 855 Fig. 10. Below are Fig. 11 and Fig. 12 with reference to Fig. 10 described.

[0052] In Fig. 11, the first antenna module 300 may include antennas 310 to 320, front-end RF circuits 330 to 340, buffers 350 and 360, and / or a switch 370. The front-end RF circuit 330 may be connected to the antenna 310 and the buffers 350 and 360, and may include a switch 331, a low-noise amplifier 332, an RX phase shifter 333, a power amplifier 334, a TX phase shifter 335, and / or a power detector 336 (also referred to as a power sensor 336). The switch 331 may connect the antenna 310 to the low-noise amplifier 332 or the power amplifier 334 according to a receive mode and / or a transmit mode. The low noise amplifier 332 can amplify a signal received by the switch 331 in the receive mode and provide an amplified signal to the RX phase shifter 333.The RX phase shifter 333 can phase shift a signal output by the low-noise amplifier 332 and provide a phase-shifted signal to the RX buffer 350. The TX phase shifter 335 can phase shift a signal received by the TX buffer 360 and provide a phase-shifted signal to the power amplifier 334. The power amplifier 334 can amplify a signal received by the TX phase shifter 335 in the transmit mode and provide an amplified signal to the switch 331. The switch 331 can provide a signal output by the power amplifier 334 to the antenna 310 in the transmit mode. The RX buffer 350 can receive signals from the front-end RF circuits 330 to 340 and provide signals to the switch 370 in the receive mode. The TX buffer 360 can provide signals received from the switch 370 in transmit mode to the front-end RF circuits 330 to 340.The switch 370 can provide a signal received by the RX buffer 350 in the receive mode as an RF signal S_RF to the outside, e.g., the first processing circuit 851 of FIG. Fig. 10, and provide the RF signal S_RF received from the first processing circuit 851 to the TX buffer 360 in the transmit mode. According to some exemplary embodiments, each of the front-end RF circuits 330 to 340 may be the same as, or similar to, the front-end RF circuit 330.

[0053] The power detection device 336 may detect the power (e.g., a power level) of a signal received via the antenna 310. For example, the power detection device 336 may detect the power of a signal traveling in a receive mode along a path that includes the antenna 310, the switch 331, the low-noise amplifier 332, and the RX phase shifter 333. According to some example embodiments, the power detection device 336 may include a voltage sensor and / or a current sensor. The front-end RF circuits 330 to 340 may each include a power detection device (the same or similar to the power detection device 336), and the power detection device may receive status signals S_STA from Fig. 10, which include information regarding detected receive power, to the controller 855 (e.g., via a connection not shown, such as a wired connection to the controller 855). In some embodiments, information regarding the total transmit power detected by the front-end RF circuits 330 to 340 may be provided to the controller 855 through the status signal S_STA, and values, e.g., an average calculated from the transmit power detected by the front-end RF circuits 330 to 340 (e.g., by a data processor 780 operating in conjunction with Fig. 16), provided to the controller 855 via the status signal S_STA as the transmit power detected by the first antenna module 300. According to some exemplary embodiments, operations described herein as being performed by the power detection device 336 may be performed by a processing circuit. According to some exemplary embodiments, the first antenna module 300 may have a different number of antennas and corresponding front-end RF circuits than in Fig. 11 shown.

[0054] In Fig. 12, a process S40, a process for obtaining information concerning the reception power of the first antenna modules 810, may be performed. For example, the controller 855 of Fig. 10 receive the status signal S_STA, which comprises information regarding the received power detected by the power detection devices included in the first antenna modules 810, as described above with reference to Fig. 11 described.

[0055] In operation S50, an operation may be performed to determine a transmission power by a first antenna module corresponding to the lowest or low reception power. If a reception power detected by a particular first antenna module among the first antenna modules 810 is significantly lower than that detected by the other first antenna modules, it may be determined that an external object is located near the first antenna module by which the low reception power is detected. Therefore, the controller 855 may determine whether to reduce the transmission power of the first antenna module corresponding to the lowest reception power from the reception power obtained in operation S40 and whether to increase the transmission power of first antenna modules corresponding to a desirable reception power.Accordingly, a user's exposure to electromagnetic waves can be reduced while maintaining wireless communication quality. An example of operation S50 is described below with reference to FIG. Fig. 13 described.

[0056] Fig. 13 is a flowchart showing an example of operation S50 from Fig. 12 according to an embodiment of the inventive concepts. As described above with reference to Fig. 12, can be done in process S50' from Fig. 13, a process for determining the transmit power by the first antenna module corresponding to the lowest receive power is performed. As in Fig. 13, operation S50' may include a plurality of operations S52, 54, 56, and 58, and in some embodiments, operation S50' may be Fig. 13 by the controller 855 Fig. 10. The following Fig. 13 with reference to Fig. 10 described.

[0057] In operation S52, an operation for extracting a first minimum power P_MIN1 (e.g., a first minimum power level) and a second minimum power P_MIN2 (e.g., a second minimum power level) may be performed. The first minimum power P_MIN1 may correspond to the lowest of the received powers of the first antenna modules 810 (e.g., a lowest power level), and the second minimum power P_MIN2 may correspond to the second lowest power level of the received powers of the first antenna modules 810 (e.g., a second lowest power level). In other words, the first minimum power P_MIN1 and the second minimum power P_MIN2 may be extracted as shown in Equation 2 below. P_MIN1=min{P_RXi|1≤i≤N}P_MIN2=min{P_RXi|1≤i≤N, P_RXi≠P_MIN1}

[0058] In equation 2, P_RX idenotes a received power detected by one of the first N antenna modules.

[0059] In operation S54, an operation for comparing a difference between the first minimum power P_MIN1 and the second minimum power P_MIN2 with a first reference value REF1 (e.g., determining whether the difference between the first minimum power P_MIN1 and the second minimum power P_MIN2 is greater than the first reference value REF1) may be performed. Since the second minimum power P_MIN2 is greater than or equal to the first minimum power P_MIN1, as shown in Fig. As shown in Figure 13, if a value P_MIN2-P_MIN1 obtained by subtracting the first minimum power P_MIN1 from the second minimum power P_MIN2 is greater than the first reference value REF1, which is a positive value, operation S56 may be performed thereafter. Otherwise, operation S50' may be terminated.

[0060] In operation S56, an operation for reducing the transmission power of a first antenna module corresponding to the first minimum power P_MIN1 may be performed. In other words, when the difference between the first minimum power P_MIN1 and the second minimum power P_MIN2 is greater than the first reference value REF1, the controller 855 may determine that an external object is closer to the first antenna module corresponding to the first minimum power P_MIN1, and therefore, the controller 855 may reduce the transmission power of the corresponding first antenna module through the control signal C_TX. According to some example embodiments, the first reference value REF1 may be a design parameter determined through empirical research.

[0061] In operation S58, an operation may be performed to increase the transmission power of at least one antenna module according to a desired reception power. Desired reception power may mean that a signal from a wireless communication device (e.g., 10 in Fig. 1) of another user reaches the first antenna module without obstruction. In some embodiments, the desirable received power may be determined based on statistical properties of received power detected by a plurality of first antenna modules (e.g., by the controller 855 and / or the data processor 780, in conjunction with Fig. 16) and can be defined as an average of a reception power of the first antenna modules or as a value increased by a multiple of the standard deviation from the average.

[0062] Fig. 14 is a block diagram showing a first antenna module 500 according to an embodiment of the inventive concepts, and Fig. 15 is a flowchart of a method for controlling exposure to wireless communication according to an embodiment of the inventive concepts. In detail, the first antenna module 500 may be Fig. 14 an example of one of the first antenna modules 810 from Fig. 10, and the procedure from Fig. 15 is a method for transmission control of a plurality of first antenna modules comprising the first antenna module 500 of Fig. 14. In some embodiments, the method of Fig. 15 from the controller 855 Fig. 10. Below are Fig. 14 and Fig. 15 with reference to Fig. 10. In the following, descriptions are omitted that are identical to those described above with reference to Fig. 11 are identical or similar to those given.

[0063] In Fig. 11, the first antenna module 500 may include antennas 510 to 520, front-end RF circuits 530 to 540, buffers 550 and 560, and / or a switch 570. The front-end RF circuit 530 may include a switch 531, a low-noise amplifier 532, an RX phase shifter 533, a power amplifier 534, a TX phase shifter 535, and / or a temperature sensor 537. The temperature sensor 537 may detect the temperature of the front-end RF circuit 530. For example, the front-end RF circuits 530 to 540 may each include a temperature sensor (e.g., the same or similar to the temperature sensor 537), and temperature sensors may detect the status signals S_STA from Fig. 10, which includes information regarding the sensed temperatures, to the controller 855 (e.g., through a connection, such as a wired connection not shown, to the controller 855). In some embodiments, information regarding all temperatures sensed by the front-end RF circuits 530 to 540 may be provided to the controller 855 through the status signal S_STA, and values, e.g., an average calculated from the temperatures sensed by the front-end RF circuits 530 to 540 (e.g., by a data processor 780 operating in conjunction with Fig. 16), provided to the controller 855 via the status signal S_STA as the temperature sensed by the first antenna module 500. According to some exemplary embodiments, each of the front-end RF circuits 530 to 540 may be the same as, or similar to, the front-end RF circuit 530. According to some exemplary embodiments, operations described herein as being performed by the temperature sensor 537 may be performed by a processing circuit. According to some exemplary embodiments, the first antenna module 500 may have a different number of antennas and corresponding front-end RF circuits than in Fig. 14 shown.

[0064] In Fig. 15, a process S60, a process for obtaining information concerning temperatures of the first antenna modules 810, may be performed. For example, the controller 855 of Fig. 10 receive the status signal S_STA, which comprises information regarding the temperatures detected by the temperature sensors included in the first antenna modules 810, as described above with reference to Fig. 14 described.

[0065] In operation S70, an operation for determining a transmission power by a plurality of first antenna modules may be performed. In the case where a transmission power is increased via a first antenna module, elements included in the first antenna module, e.g., the power amplifier 534 of Fig. 14, radiate heat due to increased power consumption. A temperature increase of the first antenna module may cause failure of the elements included in the first antenna module (e.g., the low-noise amplifier 532, the RX phase shifter 533, the power amplifier 534, and / or the TX phase shifter 535) and may also cause a temperature increase of the UE 800. Therefore, the controller 855 may reduce the transmission power by a first antenna module, for which a temperature greater than or equal to a second reference value is detected, from a plurality of first antenna modules. For example, in operation S35, Fig. 9 and process S58 from Fig. 13, the transmission power of some of a plurality of first antenna modules may be increased. However, if the temperature of the corresponding first antenna modules becomes higher than the second reference value due to the increase in transmission power, the transmission power of the corresponding first antenna modules may be reduced again. According to some exemplary embodiments, the second reference value may be a design parameter determined through empirical studies.

[0066] Fig. Figure 16 is a block diagram showing a first antenna module 700 according to an embodiment of the inventive concepts. In detail, the first antenna module 700 may be Fig. 16 an example of one of the first antenna modules 810 from Fig. 10. In the following, descriptions are omitted that are identical to those given above with reference to Fig. 11 and Fig. 14 are identical or similar to those given.

[0067] As in Fig. 16, the first antenna module 700 may include antennas 710 to 720, front-end RF circuits 730 to 740, buffers 750 and 760, a switch 770, and / or a data processor 780. A front-end RF circuit 730 may include a power sensing device 736 and / or a temperature sensor 737. Likewise, a front-end RF circuit 740 may include a power sensing device 746 and / or a temperature sensor 747. According to some example embodiments, each of the front-end RF circuits 730 to 740 may be the same as, or similar to, the front-end RF circuit 730. According to some example embodiments, operations described herein as being performed by the data processor 780, the power sensing device 736, the power sensing device 746, the temperature sensor 737, and / or the temperature sensor 747 may be performed by a processing circuit.According to some example embodiments, the first antenna module 700 may include a different number of antennas and corresponding front-end RF circuitry than in FIG. Fig. 16 shown.

[0068] The data processor 780 may receive signals output from power sensing devices 736 and / or 746 and / or temperature sensors 737 and / or 747 of the front-end RF circuits 730 to 740 included in the first antenna module 700, and may generate a status signal S_STA by processing the received signals. For example, the data processor 780 may calculate an average, a maximum or highest value, and a minimum or lowest value of a received power provided by the power sensing devices 736 and / or 746, and generate a status signal S_STA including calculated values ​​as information regarding the received power of the first antenna module 700.Also, the data processor 780 may calculate an average, a maximum or highest value, and a minimum or lowest value of temperatures provided by the temperature sensors 737 and / or 747 and generate the status signal S_STA comprising calculated values ​​as information regarding the temperature of the first antenna module 700. According to some example embodiments, the data processor 780 may transmit the status signal S_STA to the controller 855 via a connection (e.g., a wired connection not shown). In some embodiments, unlike in FIG. Fig. 16, the front-end RF circuits 730 to 740 each comprise only one of a power sensing device and a temperature sensor.

[0069] Fig. Figure 17 is a block diagram illustrating a communication device 900 according to an embodiment of the inventive concepts. In some embodiments, the communication device 900 may be incorporated in the UE 100 of Fig. 1 and can perform the operations of the controller 155.

[0070] As in Fig. As shown in Figure 17, the communication device 900 may include an application-specific integrated circuit (ASIC) 910, an application-specific instruction set processor (ASIP) 930, a memory 950, a main processor 970, and / or a main memory 990. Two or more of the ASIC 910, ASIP 930, and / or main processor 970 may communicate with each other. At least two of the ASIC 910, ASIP 930, memory 950, main processor 970, and / or main memory 990 may be integrated into a single chip.

[0071] The ASIP 930 may be an integrated circuit customized for a particular purpose and may support a dedicated instruction set for a particular application and execute instructions included in the instruction set. The memory 950 may communicate with the ASIP 930 and may be a non-volatile storage device storing a plurality of instructions to be executed by the ASIP 930. For example, the memory 950 may comprise any type of memory accessible by the ASIP 930, including, but not limited to, random access memory (RAM), read-only memory (ROM), tape, magnetic disk, optical disk, volatile memory, non-volatile memory, and combinations thereof.

[0072] Main processor 970 may control communication device 900 by executing a plurality of instructions. For example, main processor 970 may control ASIC 910 and / or ASIP 930, process data received over a wireless communication network, and / or process user input related to communication device 900. Main memory 990 may communicate with main processor 970 and may be a non-volatile storage device storing a plurality of instructions to be executed by main processor 970.For example, main memory 990 may include any type of memory accessible by main processor 970, including, but not limited to, random access memory (RAM), read-only memory (ROM), tape, magnetic disk, optical disk, volatile memory, non-volatile memory, and combinations thereof.

[0073] A method for controlling exposure to wireless communication may be performed by at least one of the devices included in the communication device 900. Fig. 17. In some embodiments, the operations of the controller 155 may be Fig.1 may be implemented as a plurality of instructions stored in memory 950, and ASIP 930 may perform at least one of the operations of the wireless communication exposure control method by executing the instructions stored in memory 950. In some embodiments, at least one of the operations of the wireless communication exposure control method may be performed by a hardware block formed by logic synthesis or the like, and such a hardware block may be included in ASIC 910.In some embodiments, at least one of the acts of the method for controlling wireless communication may be implemented as a plurality of instructions stored in main memory 990, and main processor 970 may perform at least one of the acts of the method for controlling exposure to a wireless communication unit by executing the instructions stored on main memory 990.

[0074] Conventional wireless communication devices that use high-frequency electromagnetic waves, such as millimeter waves, incorporate additional components (e.g., a proximity sensor, a gyro sensor, a touch sensor, etc.) to determine when a user is near the wireless communication device and reduce a transmission power of the wireless communication device in response to such a determination. Such conventional wireless communication devices incur excessive costs and waste physical space due to the inclusion of additional components. Also, the quality of wireless communication in conventional wireless communication devices is excessively reduced when the transmission power of the wireless communication device is reduced.

[0075] However, some example embodiments provide improved wireless communication devices capable of determining when the user is in proximity of the wireless communication device without incorporating additional components. Accordingly, the improved wireless communication devices may be less costly and / or less wasteful of limited physical space (e.g., more space-efficient). Also, the improved wireless communication devices are capable of reducing the transmit power of one antenna module and increasing the transmit power of another antenna module when it is determined that the user is in proximity of the antenna module. Therefore, the improved wireless communication devices may reduce the user's exposure to high-frequency electromagnetic waves while maintaining the quality of the wireless communication.

[0076] The various operations of the methods described above may be performed by any suitable device capable of performing the operations, such as processing circuitry. For example, the various operations of the methods described above may be performed by various hardware and / or software elements implemented in any form of hardware (e.g., processor, ASIC, etc.).

[0077] The software may comprise an ordered list of executable instructions for implementing logical functions and may be embodied in any "processor-readable medium" used by or in connection with an instruction execution system, device, or apparatus, such as a processor having one or more cores, or a system including a processor.

[0078] The blocks or acts of a method or algorithm, as well as functions described in connection with some example embodiments disclosed herein, may be embodied directly in hardware, in a software module executed by at least one processor, or in a combination of the two. When implemented in software, the functions may be stored or transmitted as one or more instructions or code on a physical, non-transitory, computer-readable medium. A software module may be available on random access memory (RAM), flash memory, read-only memory (ROM), electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), a register, a hard disk, a removable storage device, a CD-ROM, or any other form of storage medium known in the art.

Claims

[1] A signal processing device for controlling exposure to wireless communication, the signal processing device (150; 250; 650; 650', 850) comprising: a processing circuit (251; 851) which is arranged to determine at least one distance between an external object based on at least one reflection coefficient, and to control a transmission by a first antenna module (111, 112; 300; 500; 700) based on the at least one determined distance, wherein the at least one reflection coefficient includes a reflection coefficient of a second antenna module (121, 122; 621; 621'), wherein the first antenna module (111, 112; 300; 500; 700) is configured for wireless communication in a first frequency band, the second antenna module (121, 122; 621; 621') is configured for wireless communication in a second frequency band, and the second frequency band is a lower frequency band than the first frequency band. [2] The signal processing device according to claim 1, further comprising: a lookup table (657; 657') containing a plurality of combinations of reference reflection coefficients (R1 to R M ) in conjunction with a plurality of reference distances (D 11 to D KN ) includes where the first antenna module (111, 112; 300; 500; 700) is one of a plurality (210; 810) of first antenna modules (111, 112; 300; 500; 700), the second antenna module (121, 122; 621; 621') is one of a plurality (220) of second antenna modules (121, 122; 621; 621'), and the processing circuit (251; 851) is arranged to calculate a plurality of calculated reflection coefficients of the plurality (220) of second antenna modules (121, 122; 621; 621'), obtain a plurality of obtained distances to an external object from the plurality (210; 810) of first antenna modules (111, 112; 300; 500; 700) based on the plurality of calculated reflection coefficients by referring to the lookup table (657; 657'), and to control transmission by the plurality (210; 810) of first antenna modules (111, 112; 300; 500; 700) based on the plurality of obtained distances. [3] The signal processing device according to claim 2, wherein the processing circuit (251; 851) is configured to reduce a transmission power output by a specific first antenna module of the plurality (210; 810) of first antenna modules (111, 112; 300; 500; 700) according to a specific distance from a plurality of obtained distances which is less than a first distance. [4] The signal processing device according to claim 3, wherein the processing circuit (251; 851) is configured to expand a width of a beam generated by a specific first antenna module among the plurality (210; 810) of first antenna modules (111, 112; 300; 500; 700) according to a specific distance among the plurality of obtained distances that is between the first distance and a second distance, the second distance being greater than the first distance. [5] Signal processing device according to claim 2, wherein each respective first antenna module of the plurality (210; 810) of first antenna modules (111, 112; 300; 700) comprises a respective antenna (310, 320; 710, 720) and a respective power sensor (336; 736) configured to detect a power level of a signal received via the respective antenna (310, 320; 710, 720); and the processing circuit (251; 851) is configured to control transmission by the plurality (210; 810) of first antenna modules (111, 112; 300; 700) based on a plurality of power levels detected at the plurality (210; 810) of first antenna modules (111, 112; 300; 700). [6] The signal processing device according to claim 5, wherein the processing circuit (251; 851) is configured to reduce a transmission power output by a first low-power antenna module of the plurality (210; 810) of first antenna modules (111, 112; 300; 700) when a difference between a lowest power level of the plurality of power levels and a second lowest power level of the plurality of power levels is greater than a first reference value, the first low-power antenna module corresponding to the lowest power level. [7] Signal processing device according to claim 1, wherein the first antenna module (111, 112; 500; 700) comprises a temperature sensor (537; 737) configured to measure a temperature; and the processing circuit (251; 851) is configured to reduce a transmission power emitted by the first antenna module (111, 112; 500; 700) when the temperature is greater than or equal to a second reference value. [8] Signal processing device according to claim 1, wherein the first antenna module (111, 112; 300; 500; 700) is one of a plurality (210; 810) of first antenna modules (111, 112; 300; 500; 700); the second antenna module is one of a plurality (220) of second antenna modules (121, 122; 621; 621'); and the processing circuit (251; 851) is arranged to calculate a plurality of calculated reflection coefficients of the plurality of second antenna modules (121, 122; 621; 621'), obtain a plurality of obtained distances to an external object from the plurality (210; 810) of first antenna modules (111, 112; 300; 500; 700) based on the plurality of calculated reflection coefficients and a feature vector of an artificial neural network (658), wherein the feature vector of the artificial neural network (658) is trained using a plurality of reference reflection coefficients, and to control a transmission power output by the plurality (210; 810) of first antenna modules (111, 112; 300; 500; 700) based on the plurality of obtained distances. [9] Signal processing device according to claim 1, wherein the second antenna module comprises an antenna (63; 63') and a coupler (62; 62') coupled to the antenna (63; 63'); and the processing circuit (251; 851) is arranged to receive a forward coupling signal (S_FC; S_FC1) and a reverse coupling signal (S_RC; S_RC1) from the coupler (62; 62'), and to calculate a reflection coefficient based on the feedforward signal (S_FC; S_FC1) and the feedback signal (S_RC; S_RC1). [10] The signal processing apparatus according to claim 1, wherein the first frequency band is a millimeter wave (mmWave) band. [11] A signal processing device for controlling exposure to wireless communication, the signal processing device comprising: a processing circuit (251; 851) which is arranged to receive a plurality of power levels from a plurality (210; 810) of first antenna modules (111, 112; 300; 700), wherein the plurality (210; 810) of first antenna modules (111, 112; 300; 700) is configured for wireless communication in a first frequency band, wherein each first antenna module (111, 112; 300; 700) of the plurality (210; 810) of first antenna modules (111, 112; 300; 700) comprises a respective antenna (310, 320; 710, 720) and a respective power sensor (336; 736) configured to detect a respective power level of a signal transmitted via the respective antenna (310, 320; 710, 720), wherein the respective power level is one of a plurality of power levels, and reduce a transmission power output by a first low-power antenna module of the plurality (210; 810) of first antenna modules (111, 112; 300; 700) when a difference between a lowest power level of the plurality of power levels and a second lowest power level of the plurality of power levels is greater than a first reference value, wherein the first low-power antenna module corresponds to the lowest power level. [12] A signal processing device according to claim 11, wherein the processing circuit (251; 851) is arranged: to calculate a plurality of calculated reflection coefficients of a plurality (220) of second antenna modules (121, 122; 621; 621'), wherein the plurality of second antenna modules (121, 122; 621; 621') are configured for wireless communication in a second frequency band, wherein the second frequency band is a lower frequency band than the first frequency band; and to control transmission by the plurality (210; 810) of first antenna modules (111, 112; 300; 700) based on the plurality of calculated reflection coefficients. [13] A signal processing device according to claim 12, further comprising: a lookup table (657; 657') containing a plurality of combinations of reference reflection coefficients (R1 to R M ) in conjunction with a plurality of reference distances (D1 to D N ) includes wherein the processing circuit (251; 851) is arranged obtain a plurality of obtained distances to an external object from the plurality (210; 810) of first antenna modules (111, 112; 300; 700) based on the plurality of calculated reflection coefficients by referring to the lookup table (657; 657'), and to control transmission by the plurality (210; 810) of first antenna modules (111, 112; 300; 700) based on the plurality of obtained distances. [14] A terminal capable of connecting a plurality of wireless communication systems, the terminal comprising: a plurality (210; 810) of first antenna modules (111, 112; 300; 500; 700) configured to connect to a first wireless communication system using a first frequency band; a plurality (220) of second antenna modules (121, 122; 621; 621') configured to connect to a second wireless communication system using a second frequency band that is a lower frequency band than the first frequency band; and a processing circuit (251; 851) which is arranged to calculate a plurality of calculated reflection coefficients of the plurality of second antenna modules, to determine a plurality of distances to an external object based on the plurality of calculated reflection coefficients, and to control transmission by the plurality (210; 810) of first antenna modules (111, 112; 300; 500; 700) based on the plurality of determined distances. [15] Terminal according to claim 14, further comprising: a lookup table (657; 657') containing a plurality of combinations of reference reflection coefficients (R1 to R M) in conjunction with a plurality of reference distances (D1 to D N ) includes wherein the processing circuit (251; 851) is arranged obtain a plurality of obtained distances to an external object from the plurality (210; 810) of first antenna modules (111, 112; 300; 500; 700) based on the plurality of calculated reflection coefficients by referring to the lookup table (657; 657'), and to control transmission by the plurality (210; 810) of first antenna modules (111, 112; 300; 500; 700) based on the plurality of obtained distances. [16] Terminal according to claim 14, wherein each respective second antenna module of the plurality (220) of second antenna modules (121, 122; 621; 621') comprises a respective antenna (63; 63') and a respective coupler (62; 62') coupled to the respective antenna (63; 63'); and the processing circuit (251; 851) is arranged to receive a forward coupling signal (S_FC; S_FC1) and a reverse coupling signal (S_RC; S_RC1) from a specific coupler (62; 62') of a specific second antenna module (121, 122; 621; 621') from the plurality (220) of second antenna modules (121, 122; 621; 621'), and to calculate a reflection coefficient based on the feedforward signal (S_FC; S_FC1) and the feedback signal (S_RC; S_RC1). [17] Terminal according to claim 14, wherein each respective first antenna module (111, 112; 300; 700) of the plurality (210; 810) of first antenna modules (111, 112; 300; 700) comprises a respective antenna (310, 320; 710, 720) and a respective power sensor (336; 736) configured to detect a respective power level of a signal received via the respective antenna (310, 320; 710, 720); and the processing circuit (251; 851) is configured to control transmission by the plurality of first antenna modules (111, 112; 300; 700) based on a plurality of power levels detected at the plurality (210; 810) of first antenna modules (111, 112; 300; 700). [18] A method for controlling exposure to millimeter wave (mmWave) wireless communication, the method comprising: Calculating a plurality of calculated reflection coefficients of a plurality (220) of second antenna modules (121, 122; 621; 621') configured to connect to a low band wireless communication system using a frequency band lower than a millimeter wave frequency band; Determining a plurality of determined distances between an external object and a plurality (210; 810) of first antenna modules (111, 112; 300; 500; 700) based on the plurality of calculated reflection coefficients, wherein the plurality (210; 810) of first antenna modules (111, 112; 300; 500; 700) is configured to connect to a millimeter-wave wireless communication system using millimeter waves; and Controlling transmission by the plurality (210; 810) of first antenna modules (111, 112; 300; 500; 700) based on the plurality of determined distances. [19] The method of claim 18, wherein determining a plurality of determined distances comprises: Accessing a lookup table (657; 657') containing a plurality of combinations of reference reflection coefficients (R1 to R M ) in conjunction with a plurality of reference distances (D1 to D N ) includes; and Obtaining the plurality of determined distances by referring to the lookup table (657; 657'). [20] The method of claim 18, wherein determining a plurality of determined distances comprises: Obtaining the plurality of determined distances using a feature vector of an artificial neural network (658) using a plurality of reference reflection coefficients. [21] The method of claim 18, wherein controlling the transmission comprises reducing transmission power output by a particular first antenna module of the plurality (210; 810) of first antenna modules (111, 112; 300; 500; 700) that corresponds to a particular distance of the plurality of determined distances that is smaller than a first distance. [22] The method of claim 18, wherein controlling the transmission comprises expanding a width of a beam generated by a specific first antenna module (111, 112; 300; 500; 700) of the plurality (210; 810) of first antenna modules (111, 112; 300; 500; 700) corresponding to a specific distance of the plurality of determined distances that is between a first distance and a second distance, the second distance being greater than the first distance. [23] The method of claim 18, further comprising: Detecting power levels corresponding to a plurality of signals received by the plurality (210; 810) of first antenna modules (111, 112; 300; 700), wherein controlling the transmission is based on the plurality of determined distances and the plurality of power levels. [24] The method of claim 23, wherein controlling the transmission comprises: Obtaining a lowest power level from the plurality of power levels and a second lowest power level from the plurality of power levels; and Reducing a transmission power output by a first low-power antenna module of the plurality (210; 810) of first antenna modules (111, 112; 300; 700) when a difference between the lowest power level and the second lowest power level is greater than a first reference value, wherein the first low-power antenna module corresponds to the lowest power level. [25] The method of claim 18, further comprising: Obtaining a plurality of temperatures measured in the plurality of first antenna modules (111, 112; 500; 700), wherein controlling the transmission comprises reducing a transmission power output by a first antenna module having a high temperature from the plurality (210; 810) of first antenna modules (111, 112; 500; 700) at which a temperature greater than or equal to a second reference value is measured.

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