Patent Publication Number: US-11653370-B2

Title: Method of transmitting and receiving user equipment management information in wireless communication system and electronic device for performing the method

Description:
CROSS-REFERENCE TO THE RELATED APPLICATIONS 
     This application is based on and claims priority from Korean Patent Application Nos. 10-2019-0021297 and 10-2019-0080315, respectively filed on Feb. 22, 2019 and Jul. 3, 2019, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein in their entirety by reference. 
     BACKGROUND 
     Apparatus and methods consistent with exemplary embodiment of the inventive concept relate to wireless communication, and more particularly, to transmitting and receiving user equipment (UE) management information in a wireless communication system. 
     An effort for developing an improved 5 th  generation (5G) communication system or a pre-5G communication system is being made for satisfying the demand, which is increasing after a 4 th  generation (4G) communication system is commercialized, for wireless data traffic. For this reason, the 5G communication system or the pre-5G communication system is referred to as a new radio (NR) system according to the 3 rd  generation partnership project (3GPP) standard. 
     In order to realize a high data transmission rate, the 5G communication system is being considered to be implemented in a millimeter wave band (for example, a band of 28 GHz, a band of 39 GHz, etc.). In the 5G communication system, beamforming, massive multiple input multiple output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, analog beamforming, hybrid beamforming, and large scale antenna technologies are being considered for increasing a radio wave transfer distance and reducing the loss of a radio wave path in the microwave band. 
     SUMMARY 
     Various embodiments of the inventive concept provides a wireless communication system which provides a base station with frequency band information covered by each of a plurality of phase array antennas, thereby efficiently allocating resources. 
     According to an aspect of an embodiment, there is provided an electronic device including: a communication interface including a plurality of phase array antennas; a storage configured to store user equipment (UE) management information including information about at least one frequency band covered by each of the phase array antennas; and a controller configured to control to transmit the UE management information to a base station. 
     According to another aspect of the inventive concept, there is provided an operating method of an electronic device including a plurality of phase array antennas, the operating method including: storing UE management information including information about at least one frequency band covered by each of the phase array antennas; and transmitting the UE management information to a base station. 
     According to another aspect of the inventive concept, there is provided a base station including: a communication interface configured to receive UE management information from an electronic device including a plurality phrase array antennas; and a controller configured to perform resource allocation on the basis of the received UE management information. 
     According to another aspect of the inventive concept, there is provided a wireless communication system including: the above electronic device; and a base station configured to perform resource allocation on the electronic device on the basis of the UE management information, wherein the UE management information includes information about at least one frequency band covered by each of the plurality of phase array antennas. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the inventive concept will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings in which: 
         FIG.  1    is a diagram illustrating a wireless communication system according to an embodiment; 
         FIG.  2    is a block diagram of a base station according to an embodiment; 
         FIG.  3    is a block diagram of an electronic device according to an embodiment; 
         FIG.  4 A  is a block diagram of a communication interface in a case of transmitting a wireless signal, according to example embodiments, and  FIG.  4 B  is a block diagram of a communication interface in a case of receiving a wireless signal, according to an embodiment; 
         FIG.  5 A  is a circuit diagram illustrating an analog beamformer including independent phase array antennas according to an embodiment,  FIG.  5 B  is a diagram illustrating an example which manages independent phase array antennas in adjacent frequency bands according to an embodiment, and  FIG.  5 C  is a diagram illustrating an example which manages independent phase array antennas in departed frequency bands according to an embodiment; 
         FIG.  6 A  is a circuit diagram illustrating an analog beamformer including a dependent phase array antenna according to an embodiment,  FIG.  6 B  is a diagram illustrating an example which manages a dependent phase array antenna in adjacent frequency bands according to an embodiment, and  FIG.  6 C  is a diagram illustrating an example which manages a dependent phase array antenna in different frequency bands according to an embodiment; 
         FIG.  7    is a diagram illustrating an example where a signal is exchanged between a base station and an electronic device according to an embodiment; 
         FIG.  8 A  is a diagram illustrating an example which manages a dependent phase array antenna in a case of a single subcarrier interval according to an embodiment, and  FIG.  8 B  is a diagram illustrating another example which manages a dependent phase array antenna in a case of a single subcarrier interval according to an embodiment; 
         FIG.  9 A  is a diagram illustrating an example which manages a dependent phase array antenna in a case of a multi-subcarrier interval according to an embodiment, and  FIG.  9 B  is a diagram illustrating another example which manages a dependent phase array antenna in a case of a multi-subcarrier interval according to an embodiment; and 
         FIG.  10    is a flowchart illustrating scheduling performed by a base station according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The embodiments described herebelow are all exemplary, and thus, the inventive concept is not limited to these embodiments disclosed below, and may be realized in various other forms. An embodiment provided in the following description is not excluded from being associated with one or more features of another example or another embodiment also provided herein or not provided herein but consistent with the inventive concept. For example, even if matters described in a specific example are not described in a different example thereto, the matters may be understood as being related to or combined with the different example, unless otherwise mentioned in descriptions thereof. 
       FIG.  1    is a diagram illustrating a wireless communication system according to an embodiment. 
     Referring to  FIG.  1   , a base station  110  and an electronic device  120  may be provided. The base station  110  and the electronic device  120  may be provided as nodes using a wireless channel in the wireless communication system. 
     The base station  110  may be a network infrastructure for providing wireless access to the electronic device  120 . The base station  110  may have coverage which is defined as a certain geographical region on the basis of a distance enabling transmission of a signal. The base station  110  may be referred to as an access point (AP), an eNodeB (eNB), a 5 th  generation (5G) node, or a wireless point, or may be replaced by other terms having a same or similar technical meaning. 
     According to various embodiments, the base station  110  may be connected to one or more transmission/reception points (TRPs). The base station  110  may transmit a downlink signal to the electronic device  120  or may receive an uplink signal from the electronic device  120  through the one or more TRPs. 
     The electronic device  120  may be a device used by a user, and may perform communication with the base station  110  through a wireless channel. The electronic device  120  may be referred to as user equipment (UE), a mobile station, a subscriber station, a customer premises equipment (CPE), a remote terminal, a wireless terminal, or a user device, in addition to a terminal, or may be replaced by other terms having a same or similar technical meaning. 
     The base station  110  and the electronic device  120  may transmit and receive a wireless signal at a millimeter wave band (for example, 28 GHz, 30 GHz, 38 GHz, 60 GHz, etc.). In order to overcome a high attenuation characteristic of a millimeter wave, the base station  110  and the electronic device  120  may perform beamforming. Here, the beamforming may include transmission beamforming and reception beamforming. That is, the base station  110  and the electronic device  120  may assign directivity to a transmission signal or a reception signal. To this end, the base station  110  and the electronic device  120  may perform beam search, beam training, and beam management to select an optimal beam for wireless communication. 
     According to the above-described embodiment, it is described that the base station  110  transmits or receives a wireless signal to or from the electronic device  120 , but the present embodiment is not limited thereto. According to various embodiments, the base station  110  may independently transmit or receive a wireless signal to or from other electronic devices  130  and  140  as well as the electronic device  120 . For example, the base station  110  may perform beam search along with each of the electronic devices  120 ,  130 , and  140  to select an optimal beam for each of the electronic devices  120 ,  130 , and  140  from among a plurality beams, and may independently perform wireless communication. 
       FIG.  2    is a block diagram of a base station  110  according to an embodiment. 
     Referring to  FIG.  2   , the base station  110  may include a wireless communication interface  210 , a backhaul communication interface  220 , a storage  230 , and a controller  240 . 
     The wireless communication interface  210  may perform functions for transmitting and receiving a signal through a wireless channel. According to an embodiment, the wireless communication interface  210  may perform a conversion function between a baseband signal and a bit string according to physical layer specification for a system. For example, in transmitting data, the wireless communication interface  210  may encode and modulate a transmission bit string to generate complex symbols, and in receiving data, the wireless communication interface  210  may demodulate and decode a baseband signal to restore a reception bit string. Moreover, the wireless communication interface  210  may up-convert the baseband signal into a radio frequency (RF) band signal, and may transmit the RF band signal through an antenna, or may down-convert an RF band signal, received through the antenna, into a baseband signal. To this end, the wireless communication interface  210  may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), and/or the like. 
     The wireless communication interface  210  may transmit or receive a signal. For example, the wireless communication interface  210  may transmit a synchronization signal, a reference signal, system information, messages, control information, data, or the like. Also, the wireless communication interface  210  may perform beamforming. The wireless communication interface  210  may apply a beamforming weight to a signal which is to be transmitted, for assigning directivity to the signal. The wireless communication interface  210  may process a generated beam to repeatedly transmit a signal. 
     The backhaul communication interface  220  may provide an interface for performing communication with other nodes of a network. That is, the backhaul communication interface  220  may convert a bit string, transmitted from the base station  110  to another node (for example, another access node, another base station, an upper node, a core network, or the like), into a physical signal, and may convert the physical signal, received from the other node, into the bit string. 
     The storage  230  may store data such as a basic program, an application program, and configuration information for an operation of the base station  110 . The storage  230  may be configured with a volatile memory, a non-volatile memory, or a combination thereof. The controller  240  may control operations of the base station  110 . For example, the controller  240  may transmit and receive a signal through the wireless communication interface  210  and/or the backhaul communication interface  220 . Also, the controller  240  may record or read data in or from the storage  230 . To this end, the controller  240  may include at least one processor or a microprocessor, or may be a portion of a processor. 
       FIG.  3    is a block diagram of an electronic device  120  according to an embodiment. Description, which is the same as or similar to the description of  FIG.  2   , is omitted. 
     Referring to  FIG.  3   , the electronic device  120  may include a communication interface  310 , a storage  320 , and a controller  330 . 
     The communication interface  310  may perform functions for transmitting and receiving a signal through a wireless channel. For example, the communication interface  310  may perform a conversion function between a baseband signal and a bit string according to physical layer specification for a system. For example, in transmitting data, the communication interface  310  may encode and modulate a transmission bit string to generate complex symbols, and in receiving data, the communication interface  310  may demodulate and decode a baseband signal to restore a reception bit string. Moreover, the communication interface  310  may up-convert the baseband signal into an RF band signal, and may transmit the RF band signal through an antenna, or may down-convert an RF band signal, received through the antenna, into a baseband signal. For example, the communication interface  310  may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and/or the like. The communication interface  310  may perform beamforming. The communication interface  310  may apply a beamforming weight to a signal which is to be transmitted, for assigning directivity to the signal. 
     The communication interface  310  may transmit or receive a signal. The communication interface  310  may receive a downlink signal. The downlink signal may include a synchronization signal (SS), a reference signal (RS), system information, a configuration message, control information, data, downlink data, or the like. Also, the communication interface  310  may transmit an uplink signal. The uplink signal may include a random access-related signal, a reference signal (for example, a sounding reference signal (SRS), or a DM-RS (demodulation reference signal)), or uplink data. 
     The storage  320  may store data such as a basic program, an application program, and configuration information for an operation of the electronic device  120  under control of the controller  330  connected thereto. The storage  320  may be configured with a volatile memory, a non-volatile memory, or a combination thereof. Also, the storage  320  may provide the stored data on the basis of a request of the controller  330 . 
     According to various embodiments, the storage  320  may include UE management information. The UE management information includes information about a plurality of phase array antennas of the electronic device  120 . For example, the UE management information may include information about frequency bands covered or receivable by each of the plurality of phase array antennas. In other words, the UE management information may include information about frequency bands through which each of the plurality phase array antennas is able to receive a wireless signal. Herein, the terms “covered” and “receivable” may be interchangeably used. As another example, the UE management information may include information about a plurality phase array antennas corresponding to each of frequency bands. 
     The controller  330  may control operations of the electronic device  120 . For example, the controller  330  may transmit and receive a signal through the communication interface  310 . Also, the controller  330  may record or read data in or from the storage  320 . To this end, the controller  330  may include at least one processor or a microprocessor, or may be a portion of a processor. When the controller  330  is a portion of a processor, a portion of the communication interface  310  and the controller  330  may be referred to as a communication processor (CP). 
       FIG.  4 A  is a block diagram of a communication interface in a case of transmitting a wireless signal, according to an embodiment, and  FIG.  4 B  is a block diagram of a communication interface in a case of receiving a wireless signal, according to an embodiment. 
       FIG.  4 A  illustrates an example of a detailed configuration of the communication interface  310  of  FIG.  3   . In detail,  FIG.  4 A  illustrates elements for performing hybrid beamforming in a case of transmitting a wireless signal. 
     Referring to  FIG.  4 A , the communication interface  310  may include an encoder/modulator  410 , a digital beamformer  420 , first to N th  transmission paths  430 - 1  to  430 -N, and an analog beamformer  440 . N is an integer greater than 1. 
     The encoder/modulator  410  may perform channel encoding. The channel encoding may use at least one of a low density parity check (LDPC) code, a convolution code, a polar code, and a turbo code, not being limited thereto. The encoder/modulator  410  may perform constellation mapping to generate modulation symbols. 
     The digital beamformer  420  may perform beamforming on a digital signal (for example, the modulation symbols). To this end, the digital beamformer  420  may multiply the modulation symbols by beamforming weights. Here, the beamforming weights may be used for changing a magnitude (or level) and a phase of a signal, and may be referred to as a precoding matrix or a precoder. The digital beamformer  420  may output digital beamforming-performed modulation symbols to the first to N th  transmission paths  430 - 1  to  430 -N. In this case, based on a multiple input multiple output (MIMO) transmission technique, the modulation symbols may be multiplexed, or the same modulation symbols may be provided to the first to N th  transmission paths  430 - 1  to  430 -N. 
     The first to N th  transmission paths  430 - 1  to  430 -N may convert digital beamforming-performed digital signals into analog signals. To this end, each of the first to N th  transmission paths  430 - 1  to  430 -N may include an inverse fast Fourier transform (IFFT) calculator, a cyclic prefix (CP) inserter, a DAC, and an up-converter. The CP inserter may be for orthogonal frequency division multiplexing (OFDM), and a case where another physical layer scheme (for example, a filter bank multi-carrier (FBMC)) is applied may be excluded. That is, the first to N th  transmission paths  430 - 1  to  430 -N may provide an independent signal processing process on a plurality of streams generated through digital beamforming. However, based on an implementation type, some of the first to N th  transmission paths  430 - 1  to  430 -N may be used in common. 
     The analog beamformer  440  may perform beamforming on an analog signal. To this end, the analog beamformer  440  may multiply analog signals by beamforming weights. Here, the beamforming weights may be used for changing a magnitude and a phase of a signal. 
       FIG.  4 B  illustrates an example of a detailed configuration of the communication interface  310  of  FIG.  3   . In detail,  FIG.  4 B  illustrates elements for performing hybrid beamforming in a case of receiving a wireless signal. 
     According to various embodiments, the communication interface  310  may include a decoder/demodulator  450 , a digital beamformer  460 , first to N th  reception paths  470 - 1  to  470 -N, and an analog beamformer  480 . N is an integer greater than 1. 
     The decoder/demodulator  450  may perform channel decoding. The channel decoding may use at least one of an LDPC code, a convolution code, a polar code, and a turbo code, not being limited thereto. 
     According to various embodiments, the digital beamformer  460  and the analog beamformer  480  may respectively correspond to the digital beamformer  420  and the analog beamformer  440  of  FIG.  4 A . 
     The first to N th  reception paths  470 - 1  to  470 -N may convert analog beamforming-performed analog signals into digital signals. To this end, each of the first to N th  reception paths  470 - 1  to  470 -N may include a fast Fourier transform (FFT) calculator, an ADC, a CP remover, a serial-to-parallel converter, and a down-converter. In detail, each of the first to N th  reception paths  470 - 1  to  470 -N may down-convert a received signal into a baseband frequency, remove a CP to generate a serial time domain baseband signal, convert the serial time domain baseband signal into parallel time domain signals, execute an FFT algorithm to generate N parallel frequency domain signals, and convert the parallel frequency domain signals into a sequence of modulated data symbols. That is, the first to N th  reception paths  470 - 1  to  470 -N may provide an independent signal processing process on a plurality of streams generated through analog beamforming. However, based on an implementation type, some of the first to N th  reception paths  470 - 1  to  470 -N may be used in common. 
     Although  FIGS.  4 A and  4 B  and the above descriptions explain the communication interface  310  has different components or elements for transmitting a wireless signal and receiving a wireless signal, one same component or element may preform both functions. That is, the encoder/modulator  410 , the digital beamformer  420 , the first to N th  transmission paths  430 - 1  to  430 -N, and the analog beamformer  440  illustrated in  FIG.  4 A  may be the same components or elements as the decoder/demodulator  450 , the digital beamformer  460 , the first to N th  reception paths  470 - 1  to  470 -N, and the analog beamformer  480 , respectively, but may perform different functions depending on whether the wireless communication interface transmits or receives a wireless signal as described above. 
       FIG.  5 A  is a circuit diagram illustrating an analog beamformer including independent phase array antennas according to an embodiment,  FIG.  5 B  is a diagram illustrating an example which manages independent phase array antennas in adjacent frequency bands according to an embodiment, and  FIG.  5 C  is a diagram illustrating an example which manages independent phase array antennas in departed frequency bands according to an embodiment. 
     Referring to  FIG.  5 A , first to N th  local oscillators  510 - 1  to  510 -N may be provided. The first to N th  local oscillators  510 - 1  to  510 -N may respectively correspond to the first to N th  transmission paths  430 - 1  to  430 -N of  FIG.  4 A , and may be included in the analog beamformer  440 . N is an integer greater than 1. 
     That is, the first local oscillator  510 - 1  may perform frequency multiplication on a signal received from the first transmission path  430 - 1 , and may transmit the frequency-multiplied signal to a first phase array antenna  540 - 1 , and the N th  local oscillator  510 -N may perform frequency multiplication on a signal received from the N th  transmission path  430 -N and may transmit the frequency-multiplied signal to an N th  phase array antenna  540 -N. 
     Each of first to N th  phase array antennas  540 - 1  to  540 -N may convert and amplify the phases and magnitudes of input signals, and may transmit amplified signals to an external device. For example, in the first phase array antenna  540 - 1 , a signal received through the first transmission path  430 - 1  may be converted into a signal string having different phases/magnitudes or the same phase/magnitude by a plurality of phase/magnitude shifters  520 - 1 - 1  to  520 - 1 -M, amplified by a plurality of amplifiers  530 - 1 - 1  to  530 - 1 -M, and transmitted. Here, M is an integer greater than 1. 
     In the above-described embodiment,  FIG.  5 A  illustrates independent phase array antennas in a case of transmitting a wireless signal, but the inventive concept is not limited thereto. According to various embodiments, in a case of receiving a wireless signal, descriptions about independent phase array antennas may be analogized. For example, wireless signals received through each of the first to N th  phase array antennas  540 - 1  to  540 -N may be amplified by amplifiers (for example, the amplifiers  530 - 1 - 1  to  530 - 1 -M of  FIG.  5 A ). The phases and magnitudes of the amplified wireless signals may be shifted by phase/magnitude shifters (for example, the phase/magnitude shifters  520 - 1 - 1  to  520 - 1 -M of  FIG.  5 A ). The shifted phases and magnitudes may be based on values which are set through reception beamforming. For example, the phase and magnitude of a signal received through the first phase array antenna  540 - 1  and the phase and magnitude of a signal received through the N th  phase array antenna  540 -N may be shifted to different phases and magnitudes. 
     Referring to  FIG.  5 B , the electronic device  120  may manage independent phase array antennas in adjacent frequency bands. For example, the first phase array antenna  540 - 1  may receive a wireless signal transmitted through an N258 band (for example, 24,250 Hz to 27,500 Hz), or may transmit a wireless signal through the N258 band. The N th  phase array antenna  540 -N may receive a wireless signal transmitted through an N257 band (for example, 26,500 Hz to 29,500 Hz), or may transmit a wireless signal through the N257 band. 
     Each of the first phase array antenna  540 - 1  and the N th  phase array antenna  540 -N may be an independent phase array antenna. For example, the first phase array antenna  540 - 1  and the N th  phase array antenna  540 -N may be connected to different local oscillators. Therefore, when the first phase array antenna  540 - 1  is performing analog beamforming on the basis of a first set, the N th  phase array antenna  540 -N is performing analog beamforming on the basis of an N th  set differing from the first set. The first set and the N th  set may include different phase/magnitude shift values. 
     According to various embodiments, the N258 band and the N257 band may include a frequency domain (for example, 26,500 Hz to 27,500 Hz), which is common therebetween. When each of the first phase array antenna  540 - 1  and the N th  phase array antenna  540 -N transmits a wireless signal through the common frequency domain, quality may be degraded due to interference between adjacent phase array antennas. 
     Referring to  FIG.  5 C , the electronic device  120  may manage independent phase array antennas in different frequency bands. For example, the first phase array antenna  540 - 1  may receive a wireless signal transmitted through an N258 band (for example, 24,250 Hz to 27,500 Hz), or may transmit a wireless signal through the N258 band. The N th  phase array antenna  540 -N may receive a wireless signal transmitted through an N260 band (for example, 37,000 Hz to 40,000 Hz), or may transmit a wireless signal through the N260 band. According to various embodiments, when a signal is transmitted and received between different frequency bands, an influence of interference between adjacent phase array antennas illustrated in  FIG.  5 B  may be reduced. 
       FIG.  6 A  is a circuit diagram illustrating an analog beamformer including a dependent phase array antenna according to an embodiment,  FIG.  6 B  is a diagram illustrating an example which manages a dependent phase array antenna in adjacent frequency bands according to an embodiment, and  FIG.  6 C  is a diagram illustrating an example which manages a dependent phase array antenna in different frequency bands according to an embodiment. 
     Referring to  FIG.  6 A , a dependent phase array antenna including a plurality antennas are illustrated. For example, first antennas corresponding to the first phase array antenna  540 - 1  of  FIG.  5 A  and N th  antennas corresponding to the N th  phase array antenna  540 -N of  FIG.  5 A  may be connected to a local oscillator  510  in common. Here, these antennas connected to the local oscillator  510  may constitute or correspond to a single phase array antenna  610 . 
     Referring to  FIGS.  6 A and  5 A , in  FIG.  5 A , the first phase array antenna  540 - 1  may be connected to the first local oscillator  510 - 1 , and the N th  phase array antenna  540 -N may be connected to the N th  local oscillator  510 -N, and thus, the magnitude of frequency multiplication performed by the first local oscillator  510 - 1  may differ from that of frequency multiplication performed by the N th  local oscillator  510 -N, whereby each of the first local oscillator  510 - 1  and the N th  local oscillator  510 -N may independently perform analog beamforming. On the other hand, in  FIG.  6 A , a plurality of antennas may be connected to a common local oscillator, and thus, may depend on each other. For example, in a case where the first antenna performs analog beamforming on the basis of a first set, a phase and a magnitude of a signal received through the N th  antennas may be modulated and amplified based on the first set. As another example, in a case where the N th  antennas perform analog beamforming on the basis of a N th  set, a phase and a magnitude of a signal received through the first antennas may be modulated and amplified based on the N th  set. 
     In the above-described embodiment,  FIG.  6 A  illustrates the single dependent phase array antenna  610  in a case of transmitting a wireless signal, but the inventive concept is not limited thereto. According to various embodiments, in a case of receiving a wireless signal, descriptions about the single dependent phase array antenna  610  may be analogized. For example, wireless signals received through the single dependent phase array antenna  610  may be amplified by amplifiers (for example, the amplifiers  530 - 1 - 1  to  530 - 1 -M of  FIG.  6 A ). The phases and magnitudes of the amplified wireless signals may be shifted by phase/magnitude shifters (for example, the phase/magnitude shifters  520 - 1 - 1  to  520 - 1 -M of  FIG.  6 A ). The shifted phases and magnitudes may be based on values which are set through reception beamforming. For example, signals received through the single dependent phase array antenna  610  may be depend on the common local oscillator  510 , and thus, the phases and magnitudes of the received signals may be shifted to the same phases and magnitudes. 
     Referring to  FIG.  6 B , it may be understood that the first antennas and the N th  antennas respectively corresponding to the first phase array antenna  540 - 1  and the N th  phase array antenna  540 -N of  FIG.  5 B  depend on each other, and thus, constitute a phase array antenna  610 . In  FIG.  5 B , in order to receive a signal of an N258 band, the first phase array antenna  540 - 1  may perform analog beamforming according to the first set to receive an optimal reception beam, and in order to receive a signal of an N257 band, the N th  phase array antenna  540 -N may perform analog beamforming according to the N th  set to receive an optimal reception beam. On the other hand, the phase array antenna  610  of  FIG.  6 B  may not perform analog beamforming on a signal of each of the N257 band and an N258 band. Therefore, according to an embodiment, in a case where the phase array antenna  610  performs analog beamforming on the basis of the first set so as to receive a signal of the N258 band as an optimal beam, an optimal beam for the N257 band may need analog beamforming based on the N th  set, and due to this, the reception quality of the N257 band may be degraded. According to another embodiment, in a case where the phase array antenna  610  performs analog beamforming on the basis of the N t  set so as to receive a signal of the N257 band as an optimal beam, an optimal beam for the N258 band may need analog beamforming based on the first set, and due to this, the reception quality of the N258 band may be degraded. 
     Referring to  FIG.  6 C , it may be understood again that the first antennas and the N th  antennas respectively corresponding to the first phase array antenna  540 - 1  and the N th  phase array antenna  540 -N of  FIG.  5 C  depend on each other, and thus, constitute the phase array antenna  610 . In  FIG.  5 C , in order to receive a signal of the N258 band, when the first phase array antenna  540 - 1  performs analog beamforming on the basis of the first set, the first phase array antenna  540 - 1  may receive an optimal reception beam. In order to receive a signal of the N260 band, when the N th  phase array antenna  540 -N performs analog beamforming on the basis of the N th  set, the N th  phase array antenna  540 -N may receive an optimal reception beam. On the other hand, the phase array antenna  610  of  FIG.  6 C  may not perform analog beamforming based on the first set and the N th  set on a signal of each of the N258 band and the N260 band. Therefore, according to an embodiment, in a case where the phase array antenna  610  performs analog beamforming on the basis of the first set so as to receive a signal of the N258 band as an optimal beam, an optimal beam for the N260 band may need analog beamforming based on the N th  set, and due to this, the reception quality of the N260 band may be degraded. According to another embodiment, in a case where the phase array antenna  610  performs analog beamforming on the basis of the N th  set so as to receive a signal of the N260 band as an optimal beam, an optimal beam for the N258 band may need analog beamforming based on the first set, and due to this, the reception quality of the N258 band may be degraded. 
       FIG.  7    is a diagram illustrating an example where a signal is exchanged between a base station and an electronic device according to an embodiment. 
     Referring to  FIG.  7   , in operation  710 , an electronic device  120  may be connected to a base station  110 . That is, the electronic device  120  may correspond to a radio resource control (RRC) connected mode. 
     In operation  720 , the electronic device  120  may transmit terminal capability information (i.e., UE capability information) to the base station  110 . The UE capability information may include information about a frequency band receivable by the electronic device  120 , a component carrier (CC) in the frequency band, and a maximum frequency range capable of being processed based on discontinuous CC allocation in the frequency band, not being limited thereto. For example, referring to TS 38.331 v15.2.0, the UE capability information may be as following table. 
     
       
         
           
               
               
             
               
                 TABLE 1 
               
               
                   
               
             
            
               
                   
                 FreqBandList ::=           SEQUENCE (SIZE (1..maxBandsMRDC)) OF FreqBandInformation 
               
               
                   
                 FreqBandInformation ::=    CHOICE { 
               
               
                   
                     bandInformationEUTRA        FreqBandInformationEUTRA, 
               
               
                   
                     bandInformationNR             FreqBandInformationNR 
               
               
                   
                 } 
               
               
                   
                 FreqBandInformationEUTRA ::= SEQUENCE { 
               
               
                   
                     bandEUTRA                    FreqBandIndicatorEUTRA, 
               
               
                   
                     ca-BandwidthClassDL-EUTRA      CA-BandwidthClassEUTRA 
               
               
                   
                         OPTIONAL,  -- Need N 
               
               
                   
                     ca-BandwidthClassUL-EUTRA     CA-BandwidthClassEUTRA 
               
               
                   
                         OPTIONAL   -- Need N 
               
               
                   
                 } 
               
               
                   
                 FreqBandInformationNR ::=        SEQUENCE { 
               
               
                   
                     bandNR                        FreqBandIndicatorNR, 
               
               
                   
                     maxBandwidthRequestedDL            AggregateBandwith  
               
               
                   
                     OPTIONAL   -- Need N  
               
               
                   
                     maxBandwidthRequestedUL            AggregateBandwith  
               
               
                   
                     OPTIONAL,  -- Need N 
               
               
                   
                     maxCarriersRequestedDL         INTEGER (1..maxNrofServingCells)  
               
               
                   
                     OPTIONAL,    -- Need N  
               
               
                   
                     maxCarriersRequestedUL         INTEGER (1..maxNrofServingCells)  
               
               
                   
                     OPTIONAL   -- Need N : 
               
               
                   
                 } 
               
               
                   
                 AggregatedBandwith ::=           ENUMERATED {mhz50, mhz100, mhz150, mhz200, mhz250, 
               
               
                   
                 mhz300, mhz350,mhz400, mhz450, mhz500, mhz550, mhz600, mhz650, mhz700, mhz750, mhz800} 
               
               
                   
                 FeatureSetDownlink ::=             SEQUENCE {  
               
               
                   
                     featureSetListPerDownlinkCC           SEQUENCE (SIZE (1..maxNrofServingCells)), OF  
               
               
                   
                 FeatureSetDownlinkPerCC-Id, 
               
               
                   
                     intraBandFreqSeparationDL               FreqSeparationClass 
               
               
                   
                     OPTIONAL,  
               
               
                   
                 scalingFactor                           ENUMERATED 
               
               
                   
               
            
           
         
       
     
     According to various embodiments, the electronic device  120  may add UE management information to the UE capability information, and may transmit the UE capability information to the base station  110 . The electronic device  120  may periodically transmit the UE capability information to the base station  110 . For example, the UE management information may include index information about frequency bands receivable by a plurality of phase array antennas and a combination thereof and index information about a plurality of phase array antennas capable of receiving frequency bands and a combination thereof. 
     According to various embodiments, the UE management information may include information indicating indexes of phase array antennas capable of receiving a wireless signal of each frequency band for each frequency band. The information may be referred to as NeedForBeamInterruption. A NeedForBeamInterruption value may be [0−Maximum number of Phase Arrays]. That is, the NeedForBeamInterruption may include phase array antenna indexes for supporting a corresponding band within a range of a maximum number of phase array antennas capable of receiving a wireless signal from 0. For example, referring to  FIG.  5 B , NeedForBeamInterruption value of the N258 band may correspond to the first phase array antenna  540 - 1 , and NeedForBeamInterruption value of the N257 band may correspond to the N th  phase array antenna  540 -N. As another example, referring to  FIG.  5 C , a NeedForBeamInterruption value of the N258 band may correspond to the first phase array antenna  540 - 1 , and a NeedForBeamInterruption value of the N257 band may correspond to the N th  phase array antenna  540 -N. As another example, referring to  FIG.  6 B , all of the N257 band and the N258 band may correspond to the phase array antenna  610 . According to an embodiment, when NeedForBeamInterruption is included in the UE capability information, the UE capability information may be described as following table. 
     
       
         
           
               
               
             
               
                 TABLE 2 
               
               
                   
               
             
            
               
                   
                 FreqBandInformationNR ::=       SEQUENCE { 
               
               
                   
                     bandNR                      FreqBandIndicatorNR,  
               
               
                   
                     maxBandwidthRequestedDL          AggregatedBandwith 
               
               
                   
                     OPTIONAL,  -- Need N  
               
               
                   
                     maxBandwidthRequestedUL          AggregatedBandwith 
               
               
                   
                     OPTIONAL,  -- Need N  
               
               
                   
                     maxCarriersRequestedDL       INTEGER (1..maxNrofServingCells)  
               
               
                   
                     OPTIONAL,   -- Need N  
               
               
                   
                     maxCarriersRequestedUL       INTEGER (1..maxNrofServingCells)  
               
               
                   
                     OPTIONAL   -- Need N  
               
               
                   
                 } 
               
               
                   
                 AggregatedBandwith ::=         ENUMERATED {mhz50, mhz100, mhz150, mhz200, mhz250,  
               
               
                   
                 mhz300, mhz350,mhz400, mhz450, mhz500, mhz550, mhz600, mhz650, mhz700, mhz750, mhz800} 
               
               
                   
                 FeatureSetDownlink ::=             SEQUENCE { 
               
               
                   
                     featureSetListPerDowlinkCC          SEQUENCE (SIZE (1..maxNrofServingcells)) OF  
               
               
                   
                 FeatureSetDownlinkPerCC-Id,  
               
               
                   
                     NeedForBeamInterruption            INTEGER (1..maxNrofPhAs) 
               
               
                   
                 OPTIONAL   -- Need N 
               
               
                   
                     IntraBandFreqSeparationDL             FreqSeparationClass  
               
               
                   
                     OPTIONAL, 
               
               
                   
                 scalingFactor                       ENUMERATED 
               
               
                   
               
            
           
         
       
     
     According to various embodiments, the UE management information may include information indicating frequency bands enabling each phase array antenna to receive a wireless signal. The information may be referred to as NeedForBeamInterruption. A NeedForBeamInterruption value may be [BandComb1−BandComb_N]. The N may correspond to the number of combinations of all frequency bands included in a frequency range receivable by the electronic device  120 . For example, when the N258 band, the N257 band, the N261 band, and the N260 band are included in the frequency range receivable by the electronic device  120 , the index may be represented in an index mapping table as follows. 
     
       
         
           
               
               
               
               
               
               
             
               
                   
                 TABLE 3 
               
               
                   
                   
               
               
                   
                   
                 N258 band 
                 N257 band 
                 N261 band 
                 N260 band 
               
               
                   
                   
                 (24250 Hz- 
                 (26500 Hz- 
                 (27500 Hz- 
                 (37000 Hz- 
               
               
                   
                 BandComb 
                 27500 Hz) 
                 29500 Hz) 
                 28350 Hz) 
                 40000 Hz) 
               
               
                   
                   
               
             
            
               
                   
                 1 
                 ◯ 
                   
                   
                   
               
               
                   
                 2 
                   
                 ◯ 
                   
                   
               
               
                   
                 3 
                   
                   
                 ◯ 
                   
               
               
                   
                 4 
                   
                   
                   
                 ◯ 
               
               
                   
                 5 
                 ◯ 
                 ◯ 
                   
                   
               
               
                   
                 6 
                 ◯ 
                   
                 ◯ 
                   
               
               
                   
                 7 
                 ◯ 
                   
                   
                 ◯ 
               
               
                   
                 8 
                   
                   
                 ◯ 
                 ◯ 
               
               
                   
                 9 
                 ◯ 
                 ◯ 
                   
                 ◯ 
               
               
                   
                   
               
            
           
         
       
     
     Referring to Table 3, it may be seen that the number of kinds capable of combining the four frequency bands is total nine. For example, an N261 band may be included in a frequency range of the N257 band, and thus, the N261 band and the N257 band may not be counted as a total number capable of combining. That is, a NeedForBeamInterruption value of each phase array antenna may correspond to a value of 1 to 9. For example, referring to  FIG.  5 B , assuming that an N th  phase array antenna is capable of covering the N261 band (not shown), a NeedForBeamInterruption value of a first phase array antenna may correspond to 2 (the N258 band and the N257 band), and a NeedForBeamInterruption value of the N th  phase array antenna may correspond to 3 (the N258 band, the N257 band, and the N261 band). As another example, referring to  FIG.  5 C , the NeedForBeamInterruption value of the first phase array antenna may correspond to 2 (the N258 band and the N257 band), and the NeedForBeamInterruption value of the N th  phase array antenna may correspond to 1 (the N260 band). For example, when NeedForBeamInterruption is included in the UE capability information, the UE capability information may be described as following table. 
     
       
         
           
               
               
             
               
                   
               
             
            
               
                   
                 FreqBandInformationNR ::=        SEQUENCE { 
               
               
                   
                     bandNR                       FreqBandIndicatorNR, 
               
               
                   
                     maxBandwidthRequestedDL           AggregatedBandwith 
               
               
                   
                     OPTIONAL,  -- Need N 
               
               
                   
                     maxBandwidthRequestedUL           AggregatedBandwith  
               
               
                   
                     OPTIONAL,  -- Need N 
               
               
                   
                     maxCarriersRequestedDL         INTEGER (1..maxNrofServingCells)  
               
               
                   
                     OPTIONAL,  -- Need N 
               
               
                   
                     maxCarriersRequestedUL         INTEGER (1..maxNrofServingCells) 
               
               
                   
                     OPTIONAL   -- Need N 
               
               
                   
                      NeedForBeamInterruption (BandComb_1, ..., BandComb_NrofPhAs)   OPTIONAL   -- Need 
               
               
                   
                 N 
               
               
                   
                 } 
               
               
                   
                 AggregatedBandwith ::=          ENUMERATED {mhz50, mhz100, mhz150, mhz200, mhz250,  
               
               
                   
                 mhz300, mhz350,mhz400, mhz450, mhz500, mhz550, mhz600, mhz650, mhz700, mhz750, mhz800} 
               
               
                   
                 BandComb_n ::=          ENUMERATED {n257, n258, n260, n261, n257_n258, n258_n261, 
               
               
                   
                 n258_n260, n260_n261, n257_n258_n260} 
               
               
                   
               
            
           
         
       
     
     According to various embodiments, the UE management information may include information indicating component carriers grouped into one or more phase array antennas. The information may be referred to as NeedForBeamInterruption. According to an embodiment, an index indicating component carriers usable as a ServCellIndex value of quasi-co-located (QCL) information having a transmission configuration indicator (TCI) may be transmitted as a NeedForBeamInterruption value. The UE management information may include information about a plurality of frequency bands covered by a phase array antenna among the phase array antennas transmitted to the base station on the basis of transmission configuration indicator (TCI) state information. For example, when NeedForBeamInterruption is included in the UE capability information, the UE capability information may be described as following table. 
     
       
         
           
               
               
             
               
                   
               
             
            
               
                   
                 TCI-State ::=                   SEQUENCE { 
               
               
                   
                     tci-StateId                      TCI-StateId, 
               
               
                   
                     qcl-Type1                      QCL-Info, 
               
               
                   
                     qcl-Type2                      QCL-Info 
               
               
                   
                               OPTIONAL,   -- Need R 
               
               
                   
                     ... 
               
               
                   
                 } 
               
               
                   
                 QCL-Info ::=                       SEQUENCE { 
               
               
                   
                     cell                              ServCellIndex 
               
               
                   
                            OPTIONAL,  -- Need R 
               
               
                   
                     bwp-Id                        BWP-Id 
               
               
                   
                            OPTIONAL, -- Cond CSI-IRS-Indicated 
               
               
                   
                     referenceSignal                   CHOICE { 
               
               
                   
                        csi-rs                             NZP-CS-I-RS- 
               
               
                   
                 ResoureeId,  
               
               
                   
                        ssb                              SSB-Index 
               
               
                   
                     }, 
               
               
                   
                     qcl-Type                         ENUMERATED {typeA, typeB, 
               
               
                   
                 typeC, typeD}, 
               
               
                   
                     ... 
               
               
                   
                 } 
               
               
                   
               
            
           
         
       
     
     In operation  730 , the base station  110  may perform scheduling for resource allocation. The base station  110  may decode the UE management information received from the electronic device  120  to identify a frequency band which enables a plurality of phase array antennas included in the electronic device  120  to receive a wireless signal. For example, the base station  110  may identify a first frequency band and a second frequency band as a frequency band where a first phase array antenna of the electronic device  120  operates. In this case, the base station  110  may allocate resources on the basis that analog beamforming of the first frequency band and analog beamforming of the second frequency band are simultaneously performed by the first phase array antenna. For example, in a case where the first frequency band and the second frequency band operate by using different phase array antennas, even when a channel state information-reference signal (CSI-RS) for beam training is transmitted at different symbol timings, analog beamforming may be performed and the CSI-RS signal may be successfully received. On the other hand, in a case where the first frequency band and the second frequency band operate by using the same phase array antenna, when data is allocated to the first frequency band at a certain symbol timing and a CSI-RS symbol for the beam training is allocated to the second frequency band, analog beamforming may be performed for receiving the CSI-RS in the second frequency band, and thus, the phase and magnitude of a reception beam may be shifted in the first frequency band, causing failure of data reception. 
     In operation  740 , the base station  110  may transmit a CSI-RS for beam management to the electronic device  120 . The base station  110  may optimize a time, at which a CSI-RS symbol is allocated, for each frequency band on the basis of the UE management information. For example, when the first frequency band and the second frequency band correspond to different phase array antennas, a symbol timing at which the electronic device  120  transmits a CSI-RS of the first frequency band may not match a symbol timing at which the electronic device  120  transmits a CSI-RS of the second frequency band. That is, when the CSI-RS symbol is being transmitted in the first frequency band, the electronic device  120  may transmit a data symbol in the second frequency band. As another example, when the first frequency band and the second frequency band correspond to the same phase array antenna, the electronic device  120  may synchronize a symbol timing, at which the electronic device  120  transmits the CSI-RS of the first frequency band, with a symbol timing at which the electronic device  120  transmits the CSI-RS of the second frequency band. That is, the electronic device  120  may allocate resources such that beam training or beam sweeping is performed on the first frequency band and the second frequency band at the same symbol timing. 
       FIG.  8 A  is a diagram illustrating an example which manages a dependent phase array antenna in a case of a single subcarrier interval according to an embodiment, and  FIG.  8 B  is a diagram illustrating another example which manages a dependent phase array antenna in a case of a single subcarrier interval according to an embodiment. 
     Referring to  FIG.  8 A , a first frequency band and a second frequency band of a single subcarrier interval are illustrated. The single subcarrier interval may denote that a length of a symbol is the same between the first frequency band and the second frequency band. According to new radio, a subcarrier interval may be set to one of 60 KHz and 120 KHz. According to  FIG.  8 A , UE management information may not be transmitted and received between the electronic device  120  and the base station  110 , and the base station  110  may not have information about a phase array antenna, corresponding to each frequency band, of the electronic device  120 . 
     The first frequency band may receive a CSI-RS for beam training at a third symbol timing. That is, in order to perform beam training in the first frequency band, a phase array antenna may shift the phase and magnitude of a reception beam during a third symbol. 
     The second frequency band may receive a CSI-RS for beam training at a fourth symbol timing. That is, in order to perform beam training in the second frequency band, a phase array antenna may shift the phase and magnitude of a reception beam during a fourth symbol. 
     In this case, the first frequency band may receive a data signal at a fourth symbol timing. For example, a data signal may be received at the fourth symbol timing by using an optimal reception beam which is identified based on the beam training at the third symbol timing. The first frequency band and the second frequency band may be covered or controlled by the same phase array antenna, and thus, when beam training is performed in the second frequency band during the fourth symbol timing, the phase and magnitude of a reception beam of the first frequency band may be shifted. Therefore, the data signal received through the first frequency band may be received by using a reception beam having a phase and a magnitude which differ from those of an optimal beam, and in a worst case, decoding of received data may fail. 
     Referring to  FIG.  8 B , the electronic device  120  may transmit UE management information to the base station  110 . The base station  110  may obtain information about a phase array antenna of the electronic device  120  for each frequency band, based on the UE management information. For example, the base station  110  may identify that the first frequency band and the second frequency band are controlled by the same phase array antenna. According to an embodiment, the identification may be performed by receiving information indicating a combination of frequency bands for receiving a wireless signal for each phase array antenna. For example, a NeedForBeamInterruption value of a first phase array antenna may correspond to one value among 5 to 8. 
     The base station  110  may perform scheduling and resource allocation on the first frequency band and the second frequency band. For example, the electronic device  120  may identify that the whole phase and magnitude of a signal output from a phase array antenna are shifted due to beam training of the second frequency band at a fourth symbol timing, and thus, may synchronize a beam training time of the first frequency band with the fourth symbol timing in the second frequency band. Therefore, the electronic device  120  may prevent a data packet from being dropped or the reception sensitivity of a data signal of the first frequency band from being reduced due to beam training for the second frequency band at the fourth symbol timing. 
     In the above-described embodiment,  FIG.  8 B  is illustrated with respect to delaying a beam training time in the first frequency band, but the inventive concept is not limited thereto. According to various embodiments, the electronic device  120  may advance a beam training time in the second frequency band to a third symbol timing. Also, the electronic device  120  may perform control to maintain a beam training time in each of the first frequency band and the second frequency band, and receive only dummy data at the fourth symbol timing in the first frequency band. 
       FIG.  9 A  is a diagram illustrating an example which manages a dependent phase array antenna in a case of a multi-subcarrier interval according to an embodiment, and  FIG.  9 B  is a diagram illustrating another example which manages a dependent phase array antenna in a case of a multi-subcarrier interval according to an embodiment. 
     Referring to  FIG.  9 A , a first frequency band and a second frequency band of a multi-subcarrier interval are illustrated. A symbol length of the first frequency band may differ from that of the second frequency band. For example, in a case where a subcarrier interval of the first frequency band is 120 KHz and a subcarrier interval of the second frequency band may be 60 KHz, the symbol length of the first frequency band may correspond to half of a symbol length of the second frequency band. For example, a second symbol period of the second frequency band may be the same as a period corresponding to a sum of a third symbol and a fourth symbol of the first frequency band. 
     According to  FIG.  9 A , UE management information may not be transmitted and received between the electronic device  120  and the base station  110 , and the base station  110  may not have information about a phase array antenna, corresponding to each frequency band, of the electronic device  120 . 
     The first frequency band may receive a CSI-RS for beam training at a seventh symbol timing. That is, in order to perform beam training in the first frequency band, a phase array antenna may shift the phase and magnitude of a reception beam during a seventh symbol. Since the second frequency band has a subcarrier interval of 60 KHz, a seventh symbol period of the first frequency band may correspond to a first half period of a fourth symbol of the second frequency band. 
     The first frequency band may receive a CSI-RS for beam training during the seventh symbol, and may receive a data signal during an eighth symbol. On the other hand, in the second frequency band, a subcarrier interval may decrease by half, and thus, a symbol period may increase by twice, whereby the first frequency band may still receive a CSI-RS for beam training at an eighth symbol timing at which the data signal is received. Analog beamforming may be performed on the first frequency band and the second frequency band by the same phase array antenna, and thus, the phase and magnitude of a reception beam may be shifted at an eighth symbol timing in the first frequency band. Therefore, a data signal received through the first frequency band may be received by using a reception beam having a phase and a magnitude which differ from those of an optimal beam, and in a worst case, decoding of received data may fail. Accordingly, when the base station  110  performs resource allocation without considering a multi-subcarrier interval, the electronic device  120  may not receive a data signal of an eighth symbol of the first frequency band corresponding to a second half period of a fourth symbol of the second frequency band. 
     Referring to  FIG.  9 B , the electronic device  120  may transmit and receive UE management information to and from the base station  110 . The base station  110  may obtain information about a phase array antenna of the electronic device  120  for each frequency band, based on the UE management information. For example, the base station  110  may identify that the first frequency band and the second frequency band are covered or controlled by the same phase array antenna. 
     The base station  110  may perform scheduling and resource allocation on the first frequency band and the second frequency band on the basis of the multi-subcarrier interval as well as the UE management information. For example, the base station  110  may identify that a fourth symbol timing in the second frequency band corresponds to a seventh symbol and an eighth symbol of the first frequency band, and thus, may set a period, where a CSI-RS is transmitted in the first frequency band, to two symbol periods. Therefore, the electronic device  120  may prevent the phase and magnitude of a reception beam from being shifted, the reception sensitivity of a signal from being reduced, or a data packet from being dropped due to beam training of the second frequency band at the eighth symbol timing in the first frequency band. 
     In the above-described embodiment,  FIG.  9 B  is illustrated with respect to increasing a beam training time in the first frequency band by twice, but the inventive concept is not limited thereto. According to various embodiments, the base station  110  may allocate resources to maintain a beam training time in each of the first frequency band and the second frequency band, and transmit only dummy data at the eighth symbol timing in the first frequency band. 
       FIG.  10    is a flowchart illustrating scheduling performed by a base station according to an embodiment. 
     Referring to  FIG.  10   , in operation  1010 , the base station  110  may receive UE management information. The UE management information may include information about frequency bands covered by each of the plurality of phase array antennas of the electronic device. 
     In operation  1020 , the base station  110  may determine whether there are two or more frequency bands receivable by a common (or single) phase array antenna of the electronic device. For example, the UE management information may include index information indicating frequency bands enabling each phase array antenna to receive a wireless signal. Referring to Table 3 shown above, when an index value is not 1 to 4, the base station  110  may identify that there are two or more frequency bands receivable by the common phase array antenna. 
     In operation  1030 , the base station  110  may determine whether subcarrier intervals of the two or more frequency bands are the same. When subcarrier intervals of the frequency bands differ, lengths of symbols may differ, and thus, may be considered in allocating resources. When the subcarrier intervals of the two or more frequency bands differ, operation  1050  may be performed, and when the subcarrier intervals of the two or more frequency bands are the same, operation  1040  may be performed. 
     In operation  1040 , the base station  110  may allocate resources so that a beam training is performed at a same symbol timing in the two or more frequency bands. In operation  1050 , the base station  110  may allocate resources so as to perform beam training at a time corresponding to a longest symbol length among symbol lengths of the two or more frequency bands. For example, when a subcarrier interval of a first frequency band is twice a subcarrier interval of a second frequency band, a symbol length of the first frequency band may be half of a symbol length of the second frequency band, and thus, the base station  110  may allocate resources so as to perform beam training at one symbol timing in the second frequency band during two symbol timings in the first frequency band. 
     The operations or steps of the methods or algorithms described above can be embodied as computer readable codes on a computer readable recording medium, or to be transmitted through a transmission medium. The computer readable recording medium is any data storage device that can store data which can be thereafter read by a computer system. Examples of the computer readable recording medium include read-only memory (ROM), random-access memory (RAM), compact disc (CD)-ROM, digital versatile disc (DVD), magnetic tape, floppy disk, and optical data storage device, not being limited thereto. The transmission medium can include carrier waves transmitted through the Internet or various types of communication channel. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. 
     At least one of the components, elements, modules or units (collectively “components” in this paragraph) represented by a block in  FIGS.  2  to  4 B  may be embodied as various numbers of hardware, software and/or firmware structures that execute respective functions described above, according to an exemplary embodiment. For example, at least one of these components may use a direct circuit structure, such as a memory, a processor, a logic circuit, a look-up table, etc. that may execute the respective functions through controls of one or more microprocessors or other control apparatuses. Also, at least one of these components may be specifically embodied by a module, a program, or a part of code, which contains one or more executable instructions for performing specified logic functions, and executed by one or more microprocessors or other control apparatuses. Further, at least one of these components may include or may be implemented by a processor such as a central processing unit (CPU) that performs the respective functions, a microprocessor, or the like. Two or more of these components may be combined into one single component which performs all operations or functions of the combined two or more components. Also, at least part of functions of at least one of these components may be performed by another of these components. Further, although a bus is not illustrated in the above block diagrams, communication between the components may be performed through the bus. Functional aspects of the above exemplary embodiments may be implemented in algorithms that execute on one or more processors. Furthermore, the components represented by a block or processing steps may employ any number of related art techniques for electronics configuration, signal processing and/or control, data processing and the like. 
     While the inventive concept has been particularly shown and described with reference to embodiments thereof, it will be understood that various changes in form and details may be made therein without departing from the spirit and scope of the claims.