KR20200011803A - Apparatus and method for calibrating phased array antenna - Google Patents

Abstract

The present disclosure relates to a 5 ^th generation (5G) or pre-5G communication system for supporting higher data rates after a 4 ^th generation (4G) communication system such as Long Term Evolution (LTE). According to various embodiments of the present disclosure, a method for calibrating a phased array antenna may include: setting phase codes on a target radio frequency (RF) chain, at least one of calibration codes of the target RF chain; Estimating a candidate code of, a strength of the first combined signal estimated for the phase codes under the condition that the at least one candidate code corresponds to a reference phase, and a second combination measured for the phase codes Determining a three-time error of the signal, determining the calibration code based on the error, and setting the calibration code to the target RF chain to calibrate the target RF chain. Include. The first combined signal and the second combined signal include a combination of signals associated with the target RF chain and the reference RF chain. The apparatus and method according to various embodiments of the present disclosure allow for fast and accurate estimation of a calibration code by estimating a calibration code using some phase codes while considering the error of the estimated candidate code.

Description

Apparatus and method for calibrating a phased array antenna {APPARATUS AND METHOD FOR CALIBRATING PHASED ARRAY ANTENNA}

FIELD The present disclosure relates generally to calibration, and more particularly to an apparatus and method for calibrating a phased array antenna.

Efforts have been made to develop an improved 5 ^th generation (5G) communication system or pre-5G communication system to meet the increasing demand for wireless data traffic after commercialization of 4 ^th generation (4G) communication systems. For this reason, a 5G communication system or a pre-5G communication system is called a Beyond 4G network communication system or a Long Term Evolution (LTE) system (Post LTE) system.

In order to achieve high data rates, 5G communication systems are being considered for implementation in the ultra-high frequency (mmWave) band (eg, such as the 60 Gigabit (60 GHz) band). In order to mitigate the path loss of radio waves and increase the propagation distance of radio waves in the ultra-high frequency band, beamforming, massive array multiple input / output (Full-Dimensional MIMO, FD-MIMO) in 5G communication systems Array antenna, analog beam-forming, and large scale antenna techniques are discussed.

In addition, in order to improve the network of the system, 5G communication system has evolved small cells, advanced small cells, cloud radio access network (cloud RAN), ultra-dense network (ultra-dense network) , Device to device communication (D2D), wireless backhaul, moving network, cooperative communication, coordinated multi-points (CoMP), and interference cancellation And other technology developments are being made.

In addition, in 5G systems, Hybrid Frequency Shift Keying and Quadrature Amplitude Modulation (FQAM) and sliding window superposition coding (SWSC), Advanced Coding Modulation (ACM), and Filter Bank Multi Carrier (FBMC), an advanced access technology ), Non Orthogonal Multiple Access (NOMA), and Spar Code Multiple Access (SCMA) are being developed.

As described above, in order to perform communication in an ultra high frequency band such as a millimeter wave band, beamforming of a transmission signal or a reception signal is required. For example, for beam forming, a phased array antenna can be used. The phased array antenna includes a plurality of antenna elements whose phase is adjustable. When the phase of each antenna element is properly controlled, a signal may be transmitted in a specific direction or a beam in a specific direction may be formed.

Calibration of a phased array antenna includes a phase code for each antenna element such that when signals of the same phase are input to the antenna elements included in the phased array antenna, the signals passing through the antenna elements all have the same phase. ) Can be defined. Once the phased array antenna is calibrated, the phased array antenna can form a beam in a specific direction by setting a phase code corresponding to the specific direction to each antenna element. Therefore, in order to efficiently perform beamforming using the phased array antenna, proper calibration for the phased array antenna is required.

Based on the discussion as described above, the present disclosure provides an apparatus and method for calibrating a phased array antenna.

In addition, the present disclosure is an apparatus for estimating a candidate code for a calibration code of a target RF chain using some phase codes of available phase codes that may be set in a target radio frequency (RF) chain. And methods.

The present disclosure also provides an apparatus and method for determining a calibration code in view of an error for estimated candidate codes.

The present disclosure also provides an apparatus and method for determining the relevance of measurement values for estimating a calibration code.

In addition, the present disclosure provides an apparatus and method for performing calibration according to the type of calibration.

The present disclosure also provides an apparatus and method for transmitting a signal or forming a beam in a desired direction using a phased array antenna after calibration.

According to various embodiments of the present disclosure, a method for calibrating a phased array antenna may include: setting phase codes on a target radio frequency (RF) chain, at least one of calibration codes of the target RF chain; Estimating a candidate code of, a strength of the first combined signal estimated for the phase codes under the condition that the at least one candidate code corresponds to a reference phase, and a second combination measured for the phase codes Determining a three-time error of the signal, determining the calibration code based on the error, and setting the calibration code to the target RF chain to calibrate the target RF chain. Include. The first combined signal and the second combined signal include a combination of signals associated with the target RF chain and the reference RF chain.

According to various embodiments of the present disclosure, an apparatus for calibrating a phased array antenna may include: setting phase codes in a target RF chain to estimate at least one candidate code for a calibration code of the target RF chain, wherein the at least one Determine an intensity of the first combined signal estimated for the phase codes and a three-time error of the second combined signal measured for the phase codes under the condition that the candidate code of corresponds to the reference phase; And a controller configured to determine the calibration code, set the calibration code to the target RF chain, and calibrate the target RF chain. The first combined signal and the second combined signal include a combination of signals associated with the target RF chain and the reference RF chain.

The apparatus and method according to various embodiments of the present disclosure allow for fast and accurate estimation of a calibration code by estimating a calibration code using some phase codes while considering the error of the estimated candidate code.

Apparatus and method according to various embodiments of the present disclosure, by determining the relevance of the measurement values for estimating the calibration code, it is possible to detect the error occurred during the calibration process early, it is assumed that the wrong calibration code is estimated It can prevent.

Effects obtained in the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned above may be clearly understood by those skilled in the art from the following description. will be.

1 illustrates a phased array antenna according to various embodiments of the present disclosure.
2A and 2B illustrate a first configuration of a calibration device according to various embodiments of the present disclosure.
3 is a flowchart illustrating a calibration device according to various embodiments of the present disclosure.
4 is a flowchart for determining a candidate code for a calibration code according to various embodiments of the present disclosure.
5A and 5B illustrate graphs for indicating estimation of candidate codes according to various embodiments of the present disclosure.
6 illustrates a flowchart for determining an error for a candidate code according to various embodiments of the present disclosure.
7A and 7B illustrate graphs showing errors for estimated candidate codes according to various embodiments of the present disclosure.
8 illustrates examples of calibration results according to various embodiments of the present disclosure.
9 illustrates a flowchart for confirming the relevance of the estimated strength of a test signal according to various embodiments of the present disclosure.
10A and 10B show other examples of calibration results according to various embodiments of the present disclosure.
11 illustrates a flowchart for confirming validity of an estimated candidate code according to various embodiments of the present disclosure.
12 is a diagram illustrating a relationship between a validity of an estimated test signal strength and a validity of an estimated candidate code according to various embodiments of the present disclosure.
13 is a flowchart for determining the validity of the strength of a reference signal measured according to various embodiments of the present disclosure.
14 is a flowchart illustrating overall operations of a calibration device according to various embodiments of the present disclosure.
15 is a flowchart for determining a calibration code in consideration of an additional candidate code according to various embodiments of the present disclosure.
16 is a graph illustrating a function of combined signal strength for an additional candidate code according to various embodiments of the present disclosure.
17 illustrates phase codes set on RF chains as a result of calibration according to various embodiments of the present disclosure.
18 illustrates a type of calibration according to various embodiments of the present disclosure.
19A and 19B illustrate signal exchange between communication devices for online calibration according to various embodiments of the present disclosure.
20 is a flowchart illustrating on-line calibration according to various embodiments of the present disclosure.
21 illustrates a flowchart for forming a beam in a specific direction after calibration according to various embodiments of the present disclosure.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the scope of other embodiments. Singular expressions may include plural expressions unless the context clearly indicates otherwise. The terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by one of ordinary skill in the art as described in the present disclosure. Among the terms used in the present disclosure, terms defined in the general dictionary may be interpreted as having the same or similar meaning as the meaning in the context of the related art, and ideally or excessively formal meanings are not clearly defined in the present disclosure. Not interpreted as In some cases, even if terms are defined in the present disclosure, they may not be interpreted to exclude embodiments of the present disclosure.

In various embodiments of the present disclosure described below, a hardware approach is described as an example. However, various embodiments of the present disclosure include technology that uses both hardware and software, and thus various embodiments of the present disclosure do not exclude a software-based approach.

The present disclosure relates to an apparatus and method for calibrating a phased array antenna in a wireless communication system. Specifically, the present disclosure uses some phase codes of available phase codes that may be set in each radio frequency (RF) chain of a phased array antenna to quickly generate a candidate code for a calibration code of each RF chain. A technique for estimating and accurately estimating a calibration code in consideration of an error for a candidate code will now be described.

Terms used to describe signals used in the following description, terms referring to network entities, terms referring to components of devices, and the like are illustrated for convenience of description. Accordingly, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meanings may be used.

1 illustrates a phased array antenna 100 according to various embodiments of the present disclosure. Referring to FIG. 1, the phased array antenna 100 includes a plurality of RF chains 110-1 to 110 -N. Hereinafter, for the convenience of description, the configurations and functions of the configurations of the RF chain 110-1 will be described, but for convenience of description, the descriptions of other RF chains (eg, RF chains 110-2 to 110-N) are described. The configurations may also perform the same or similar functions as those of the RF chain 110-1.

The mixer 110-1-1 may convert a center frequency of the input signal and output a signal having the converted center frequency. For example, the mixer 110-1-1 may convert an intermediate frequency (IF) signal into an RF signal or convert an RF signal into an IF signal. Here, the frequency of the RF signal is expressed as the sum of the frequency of the IF signal and the frequency of the local oscillator (LO) signal, whereas the frequency of the IF signal is expressed as the result of subtracting the frequency of the LO signal from the frequency of the RF signal. Can be. To this end, the mixer 110-1-1 may be connected to the LO.

The phase shifter 110-1-3 may convert a phase of an input signal and output a signal having the converted phase. For example, the phase shifter 110-1-3 may lag the phase of the input signal or advance the phase. A phase code of one of a plurality of phase codes may be set in the phase converter 110-1-3. The plurality of phase codes may correspond to one of phases in the range of 0 degrees to 360 degrees, respectively, and each different phase codes may correspond to respective different phases. For example, if the possible phase codes that can be set in phase shifter 110-1-3 are 0 to 15 (ie 16) in decimal, then the phase corresponding to phase code n is 2π / 16 × n. Can be. The above-described number of phase codes and a corresponding method between phase codes and phases are exemplary and various modifications are possible. When a specific phase code is set in the phase converter 110-1-3, the phase converter 110-1-3 may change the phase of the signal input to the phase converter 110-1-3 to a phase corresponding to the set phase code. The signal of the phase can be output. The phase code can be set in the phase converter 110-1-3 by a control signal for the phase converter 110-1-3, and the phase code set in the phase converter 110-1-3 can be set for the phase converter 110-1-3. It can be changed to another phase code by the control signal. According to various embodiments of the present disclosure, the phase code may also be referred to as a phase value or a phase shifter code (PS code). In addition, setting a phase code in a phase converter (eg, phase converter 110-1-3) may be understood as setting a phase code in an RF chain (eg, RF chain 110-1) including the phase converter.

Amplifiers 110-1-5 may amplify the input signal. The amplifier 110-1-5 may provide the amplified signal to the radiator 110-1-7. The radiator 110-1-7 may convert the input electrical signal into electromagnetic waves and radiate the electromagnetic waves into a free space.

Signal 120-1 is transmitted from RF chain 110-1 through mixer 110-1-1, phase shifter 110-1-3, amplifier 110-1-5 and radiating element 110-1-7, or radiating element It can be received by the RF chain 110-1 via 110-1-7, amplifier 110-1-5, phase converter 110-1-3 and mixer 110-1-1. Similarly, signal 120-2 may be transmitted from RF chain 110-2, or received by RF chain 110-2, and signal 120-N may be transmitted from RF chain 110-N, or may be received by RF chain 110-N. Can be received.

If the plurality of RF chains 110-1 to 110-N transmit or receive signals 120-1 to 120-N at the same phase, the signals 120-1 to 120-N form a plane wave as a whole. And may propagate in a specific direction. The signals 120-1 to 120 -N propagating in a specific direction may form a beam (eg, beam 130) in a specific direction. If phase codes are set on the RF chains 110-1 to 110-N such that the phases of the signals 120-1 to 120-N are the same, the RF chains 110-1 to 110- to change the direction of the beam in a specific direction. The phase codes to be set to N may be uniquely determined based on the direction. Thus, once the phase codes are set in the RF chains 110-1 through 110-N such that the phases of the signals 120-1 through 120-N are the same, the communication device including the phased array antenna 100 corresponds to the desired beam direction. The phase codes may be set in the RF chains 110-1 to 110 -N, and a beam of a desired direction may be formed or the beam may be steered through the phased array antenna 100.

According to various embodiments of the present disclosure, the calibration of the phased array antenna is performed when the signals of the same phase are input to the RF chains (eg, the RF chains 110-1 to 110-N) included in the phased array antenna. This means setting the phase codes on the RF chains so that the signals passing through them all have the same phase. Calibration may be performed for each of the RF chains 110-1 to 110 -N. For example, when calibration is performed on the RF chain 110-1, a phase code may be set on the RF chain 110-1 such that the phase of the signal 120-1 is equal to the phase of a signal associated with the reference RF chain. Here, the reference RF chain refers to an RF chain that maintains a phase code for calibration of at least one other RF chain. The reference RF chain may be one of the plurality of RF chains 110-1 to 110 -N. For example, when the reference RF chain is 110-1, calibration may be performed on the remaining RF chains 110-2 to 110 -N. In this case, the remaining RF chains 110-2 to 110 -N to be calibrated may be referred to as a 'target RF chain', or simply a 'target RF chain'.

If calibration has been performed for one RF chain, that RF chain can serve as a reference RF chain for calibration of another RF chain. In other words, the reference RF chain can be changed while calibrating the plurality of RF chains. For example, when the RF chain 110-1 is used as a reference RF chain for calibration of the RF chain 110-2, the RF chain 110-2 may be used as a reference RF chain for calibration of the RF chain 110-3.

Calibration for each of the plurality of RF chains 110-1 to 110 -N included in the phased array antenna 100 may be performed by a calibration device. In other words, the calibration device may calibrate each of the plurality of RF chains 110-1 to 110 -N included in the phased array antenna 100. According to various embodiments of the present disclosure, calibrating each of the plurality of RF chains 110-1 to 110 -N included in the phased array antenna 100 may be understood as calibrating the phased array antenna 100, and calibration is performed. The phased array antenna to be referred to as 'target phased array antenna'.

The configuration of a calibration device for calibrating the phased array antenna 100 is described in more detail in FIGS. 2A and 2B.

2A illustrates a first configuration of a calibration device 200 according to various embodiments of the present disclosure. The terms '~', '~', etc. used below mean a unit that processes at least one function or operation, which may be implemented by hardware or software, or a combination of hardware and software.

Referring to FIG. 2A, the calibration device 200 may be a measuring instrument for calibrating the phased array antenna 100. In this case, the calibration device 200 may include a controller 210, a transceiver 220, and a reference antenna 230. In FIG. 2A, for convenience of description, it is assumed that the calibration apparatus 200 calibrates the phased array antenna 100, but this is exemplary, and the calibration apparatus 200 may calibrate any phased array antenna.

The controller 210 controls overall operations of the calibration device 200. For example, the controller 210 may control the transceiver 220 to generate a calibration signal. In addition, the controller 210 may control the transceiver 220 to transmit or receive a signal through the reference antenna 230. The controller 210 may include at least one processor or a microprocessor or may be part of a processor to perform the above-described control operation.

According to various embodiments of the present disclosure, the controller 210 may set a phase code in each of the RF chains and change the set phase code. To this end, the controller 210 may transmit a control signal for setting or changing a phase code to respective RF chains. In addition, the controller 210 may control an on / off state of each RF chain. In other words, the controller 210 may turn on or off respective RF chains. To this end, the controller 210 may block or maintain a supply voltage of each of the RF chains. In addition, the controller 210 may transmit a control signal (eg, an enable signal) for controlling an on / off state to each of the RF chains.

According to various embodiments of the present disclosure, the controller 210 may measure a strength of a signal associated with the phased array antenna 100. For example, the control unit 210 may measure the strength of a signal transmitted from each RF chain in the phased array antenna 100, and measure the strength of a combined signal of signals transmitted from two or more RF chains. have. Here, the combined signal may be represented as a vector sum of the signals. As another example, the controller 210 may measure the strength of a signal received by each RF chain in the phased array antenna 100 and measure the strength of a combination signal of signals received by two or more RF chains.

According to various embodiments of the present disclosure, the strength of the signal y may refer to the magnitude (| y |) of the signal y, or may refer to the power y ² of the signal y. In other words, the strength of the signal may include at least one of the magnitude of the signal and the power of the signal. In addition, according to various embodiments of the present disclosure, a signal associated with an element (eg, an RF chain, a phased array antenna, a communication device) may refer to a signal transmitted from or received from the element. For example, a signal associated with a reference RF chain means a signal transmitted from a reference RF chain or a signal received by the reference RF chain. The signal related to the target RF chain means a signal transmitted from the target RF chain or a signal received by the target RF chain. According to various embodiments of the present disclosure, a signal associated with a reference RF chain may be referred to as a 'reference signal' and a signal associated with a target RF chain may be referred to as a 'test signal'.

The transceiver 220 may transmit or receive a signal through the reference antenna 230. For example, the transceiver 220 may generate a calibration signal for calibrating the phased array antenna 100. The transceiver 220 may provide the generated calibration signal to the phased array antenna 100 so that the signal is transmitted from RF chains in an on state of the phased array antenna 100. The transceiver 220 may receive a signal transmitted from the phased array antenna 100 through the reference antenna 230, and may provide information about the received signal to the controller 210. As another example, the transceiver 220 may transmit a calibration signal through the reference antenna 230. The transceiver 220 may enable the phased array antenna 100 to receive a signal transmitted from the reference antenna 230, and may provide information about the signal received by the false array antenna 100 to the controller 210. For example, the transceiver 220 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a digital to analog converter (DAC), an analog to digital converter (ADC), etc. to generate, transmit, and / or receive a signal. Can be.

2B illustrates a second configuration of a calibration device 200 according to various embodiments of the present disclosure. The terms '~', '~', etc. used below mean a unit that processes at least one function or operation, which may be implemented by hardware or software, or a combination of hardware and software.

Referring to FIG. 2B, the calibration device 200 may be a communication device including a phased array antenna 100. In other words, the calibration device 200 may self-calibrate the phased array antenna 100 included in the calibration device 200. For example, the communication device may be a base station or a terminal. According to various embodiments of the present disclosure, a base station may include an 'access point (AP)', 'eNodeB (eNB)', '5G generation node', and 'wireless' in addition to a base station. Point (wireless point), “transmission / reception point (TRP)” or other terms having equivalent technical meanings. A terminal may be a terminal other than a user equipment (UE), a mobile station, a subscriber station, a remote terminal, or a wireless terminal. ) "," Customer premises equipment "(CPE), or" user device "or other terms having equivalent technical meanings. When the calibration device 200 is a communication device including the phased array antenna 100, the calibration device 200 may include a communication unit 250, a storage unit 260, and a control unit 270.

The communication unit 250 performs functions for transmitting and receiving a signal through a wireless channel. For example, the communication unit 250 performs a baseband signal and bit string conversion function according to the physical layer standard of the system. For example, during data transmission, the communication unit 250 generates complex symbols by encoding and modulating a transmission bit string. In addition, when receiving data, the communication unit 250 restores the reception bit string by demodulating and decoding the baseband signal. In addition, the communication unit 250 up-converts the baseband signal to an RF band signal, transmits the signal through an antenna, and downconverts the RF band signal received through the antenna to the baseband signal. For example, the communicator 250 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like.

In addition, the communication unit 250 may include a plurality of transmission and reception paths. Furthermore, the communicator 250 may include at least one antenna array (eg, phased array antenna 100) composed of a plurality of antenna elements. In other words, the communication unit 250 may include a plurality of RF chains, and may perform beamforming based on the phased array antenna 100 and / or the plurality of RF chains. In terms of hardware, the communication unit 250 may be configured of a digital circuit and an analog circuit (eg, a radio frequency integrated circuit (RFIC)). Here, the digital circuit and the analog circuit can be implemented in one package.

The communication unit 250 transmits and receives a signal as described above. Accordingly, all or part of the communication unit 250 may be referred to as a 'transmitter', 'receiver' or 'transceiver'. In addition, in the following description, transmission and reception performed through a wireless channel are used by the communication unit 250 to mean that the above-described processing is performed.

According to various embodiments of the present disclosure, the communication unit 250 may perform the same or similar function as the transceiver 220. For example, the communicator 250 may provide a calibration signal to the phased array antenna 100 and detect the calibration signal processed by the phased array antenna 100 through a feedback loop 280. As another example, the communication unit 250 may provide a calibration signal to the phased array antenna 100 through a feedback loop 280, and detect a signal processed by the phased array antenna 100. The communication unit 250 may provide the controller 270 with a government relating to the detected signal.

The storage unit 260 stores data such as a basic program, an application program, and setting information for the operation of the calibration device. The storage unit 260 may be configured of a volatile memory, a nonvolatile memory, or a combination of the volatile memory and the nonvolatile memory. The storage unit 260 provides the stored data according to a request of the controller 270.

The controller 270 controls overall operations of the calibration device. For example, the controller 270 transmits and receives a signal through the communication unit 250. In addition, the controller 270 records and reads data in the storage 260. The controller 270 may perform functions of a protocol stack required by a communication standard. To this end, the controller 270 may include at least one processor or a micro processor, or may be part of a processor. In addition, a part of the communication unit 250 and the control unit 270 may be referred to as a communication processor (CP).

According to various embodiments of the present disclosure, the controller 270 may perform the same or similar function as the controller 210. For example, the controller 270 may control the communicator 250 to generate a calibration signal. In addition, the controller 270 may control the communication unit 250 to provide a calibration signal to the phased array antenna 100 or to detect the calibration signal through the phased array antenna 100. As another example, the controller 270 may control the communicator 250 to provide a calibration signal to the phased array antenna 100 through a feedback loop 280 or to detect a calibration signal processed by the phased array antenna 100 through a feedback loop 280.

Although not shown, when the calibration device 200 is a base station, the calibration device 200 may further include a backhaul communication unit. The backhaul communication unit may provide an interface for communicating with other nodes in the network. That is, the backhaul communication unit converts a bit string transmitted from a base station to another node, for example, another access node, another base station, an upper node, a core network, etc. into a physical signal, and converts a physical signal received from the other node into the bit string. I can convert it.

As another example, even if the calibration device 200 is a base station, the calibration device 200 may not include a backhaul communication unit. In this case, the calibration device 200 may communicate with other nodes in the network (eg, another access node, another base station, an upper node, a core network) through a wireless backhaul, which is a kind of wireless channel, using the communication unit 250. Can be.

According to various embodiments of the present disclosure, the controller 210 and / or the controller 270 estimates candidate codes for a calibration code of the target RF chain by using some phase codes among possible phase codes that may be set in the target RF chain, and candidate codes. The optimal calibration code among the candidate codes may be determined in consideration of the error of, and the target RF chain may be calibrated by setting the calibration code to the target RF chain. For example, the controller 210 and / or the controller 270 may control the calibration apparatus to perform operations according to various embodiments described below.

The calibration device may select one of the RF chains of the phased array antenna as the reference RF chain and the other as the target RF chain for calibration. After completing the calibration for the selected target RF chain, the calibration apparatus may sequentially calibrate one by one for the remaining RF chains. Calibration for the target RF chain sets a phase code in the target RF chain such that when signals of the same phase are input to the target RF chain and the reference RF chain, the signals passing through the target RF chain and the reference RF chain have the same phase. Means that. If the phase of a signal (hereinafter referred to as a 'test signal for a specific phase code') associated with the target RF chain in which a specific phase code is set and the phase of the reference signal (hereinafter referred to as a 'reference phase') are the same, The strength of the combined signal of the test signal and the reference signal may be maximized. As another example, when the difference between the phase and the reference phase of the test signal for a particular phase code is 180 °, the strength of the combined signal of the test signal and the reference signal may be minimized.

According to various embodiments of the present disclosure, the phase code to be set in the target RF chain so that the phase of the test signal is the same as the reference phase may be referred to as a 'calibration code' or 'optimal phase code'. In addition, the combination signal of the test signal and the reference signal means a vector sum and / or a combination of the test signal and the reference signal, and may be referred to simply as the combination signal in the present disclosure. Furthermore, the combination signal of the reference signal and the test signal for a specific phase code may be referred to simply as a combination signal for a specific phase code.

The calibration device must determine the calibration code of the target RF chain in order to calibrate the target RF chain. For example, the calibration device may determine the phase code (ie, the calibration code) in which the strength of the combined signal is maximized based on all of the possible phase codes that may be set in the target RF chain. According to various embodiments of the present disclosure, possible phase codes that may be set in the target RF chain may be referred to as possible phase codes of the target RF chain. As another example, the calibration device determines a phase code at which the strength of the combined signal is minimized, based on all of the possible phase codes that can be set in the target RF chain, and a calibration code with a code difference of 180 ° for the determined phase code. Can be determined.

Since the above-described calibration methods take into account all possible phase codes that can be set in the target RF chain, a time for calibrating the target RF chain (hereinafter, referred to as a 'calibration time') may take a lot. Accordingly, various embodiments of the present disclosure may provide an apparatus capable of estimating candidate codes for a calibration code of a target RF chain using some phase codes among possible phase codes that may be set in the target RF chain to reduce calibration time. And methods. In various embodiments of the present disclosure, the 'candidate code' refers to a phase code estimated as a calibration code using some phase codes among possible phase codes that may be set in a target RF chain. For example, a calibration device according to various embodiments of the present disclosure may estimate a candidate code for a calibration code of a target RF chain using a pair of phase codes as illustrated in FIG. 4.

When the calibration device estimates the calibration code using some of the possible phase codes that can be set in the target RF chain, reliability or relevance to the estimated calibration code may be a problem. For example, if a measurement error occurs in a situation in which a specific phase code is set in the target RF chain to measure the strength of the combined signal, the strength of the wrong combined signal may be estimated and estimated based on the strength of the combined signal. The code may also be a fail code. Accordingly, various embodiments of the present disclosure estimate a plurality of candidate codes for a calibration code and increase a candidate code having the smallest error in consideration of an error for each candidate code in order to increase reliability or validity of the estimated calibration code. Provided are an apparatus and a method for determining a as a calibration code. In addition, various embodiments of the present disclosure determine the validity of a measurement value and / or an estimated value based on the measurement value (eg, the validity of the strength of the reference signal, the validity of the strength of the test signal, and the validity of the code difference between candidate codes) An apparatus and method are provided for the following.

The calibration device can calibrate an external phased array antenna (eg, factory calibration). In addition, when the calibration device is a communication device such as a base station and / or a terminal, the calibration device may include a phased array antenna therein and may calibrate the phased array antenna included therein (eg, self calibration). (self-calibration)). Furthermore, when the calibration device is a communication device, the calibration device transmits a combination signal or an individual signal associated with a single RF chain to another communication device for calibration of a phased array antenna included therein, and a signal measured by another communication device. Information may be received from another communication device, and the phased array antenna may be calibrated based on the received information (e.g., online calibration. Various embodiments of the present disclosure provide for each factory calibration, self calibration, and An apparatus and method for performing on-line calibration are provided.

In FIG. 3, an operation method of a calibration apparatus for estimating a candidate code for a calibration code and determining a calibration code in consideration of an error for the candidate code is described.

3 is a flowchart illustrating a calibration device according to various embodiments of the present disclosure. 3 illustrates a method of operating the calibration device 200.

Referring to FIG. 3, in step 301, the calibration apparatus sets phase codes on a target RF chain to estimate at least one candidate code for a calibration code of the target RF chain. For example, the calibration apparatus sets a pair of respective phase codes in the target RF chain, and estimates a candidate code for the calibration code of the target RF chain using the pair of phase codes. Specific methods for estimating candidate codes for calibration codes are described in more detail with reference to FIGS. 4 and 5A and 5B below.

In step 303, the calibration apparatus determines the strength of the first combined signal estimated for the phase codes under the condition that the reference phase corresponds to the at least one candidate code, and the three-period error of the second combined signal measured for the phase codes. Determine. In other words, the calibration device may determine an error for the estimated candidate code. When the calibration apparatus assumes that the reference phase corresponds to the estimated candidate code (i.e., it is unknown whether the reference phase actually corresponds to the estimated candidate code), the theoretical strength of the combined signal for each phase code is theoretically determined. (theoretically) can be estimated. In addition, the calibration apparatus may actually measure the strength of the combined signal for each phase code to obtain the measured strength of the combined signal. The calibration device can determine the strength of the combined signal theoretically estimated for each phase code and the three-year error of the actually measured combined signal.

In operation 305, the calibration apparatus determines a calibration code based on the error. For example, the calibration apparatus may determine errors for a plurality of candidate codes, and determine a candidate code having the smallest error among the plurality of candidate codes as a calibration code. A detailed method of determining an error for the candidate code and determining a calibration code based on the error will be described in more detail with reference to FIGS. 6 and 7A and 7B below.

In step 307, the calibration device sets a calibration code to the target RF chain, and calibrates the target RF chain. In other words, the calibration device may set the calibration code to the target RF chain so that the phase of the test signal becomes the same as the reference phase. Although not shown, the calibration apparatus may select another RF chain that is not calibrated after step 307, and calibrate the selected RF chain.

4 is a flowchart for determining a candidate code for a calibration code according to various embodiments of the present disclosure. 4 illustrates a method of operating the calibration device 200. In FIG. 4, the first phase code and the second phase code are phase codes that can be set in the target RF chain, and candidate codes for the calibration code of the target RF chain are estimated based on the first phase code and the second phase code. do.

Referring to FIG. 4, in operation 401, the calibration apparatus determines a phase difference between a phase corresponding to the first phase code and a reference phase based on the strength of the combined signal measured for the first phase code. The phase corresponding to the first phase code may be preceded or delayed by the reference phase.

In operation 403, the calibration apparatus determines a phase state of the phase difference based on the strength of the combined signal measured for the second phase code. According to various embodiments of the present disclosure, the phase state of the phase difference may indicate which phase of the phases on which the phase difference is based and which phase is delayed. For example, the calibration device may determine whether the phase corresponding to the first phase code is earlier or delayed.

In operation 405, the calibration apparatus estimates a candidate code for the calibration code based on the phase difference and the phase state of the phase difference. For example, if the phase corresponding to the first phase code precedes the reference phase, the calibration apparatus may estimate a phase code that causes the phase corresponding to the first phase code to be delayed by the phase difference as a candidate code for the calibration code. Can be. As another example, when the phase corresponding to the first phase code is delayed than the reference phase, the calibration apparatus may estimate a phase code that causes the phase corresponding to the first phase code to be preceded by the phase difference as a candidate code for the calibration code. have.

As described above, the calibration apparatus may estimate a candidate code for the calibration code based on the pair of phase codes (eg, the first phase code and the second phase code). The calibration apparatus may estimate candidate codes for calibration codes based on different pairs of phase codes, in which case each candidate code determined based on a pair of different phase codes may be the same or different from each other. .

5A and 5B illustrate graphs for indicating estimation of candidate codes according to various embodiments of the present disclosure. In graphs 510 and 520 of FIGS. 5A and 5B, the horizontal axis represents a phase corresponding to the phase code set in the target RF chain, and the vertical axis represents the strength of the combined signal.

5A and 5B, to estimate the first candidate code 521 and the second candidate code 523 for the calibration code of the target RF chain, the first phase code 511, the second phase code 513, and the third phase code 515. Can be considered. For convenience of explanation, the code difference between the first phase code 511 and the second phase code 513 corresponds to a phase difference of 90 °, and the code difference between the second phase code 513 and the third phase code 515 corresponds to a phase difference of 90 °. This is assumed. However, this is exemplary and the code difference of the phase codes required to be set in the target RF chain in order to estimate the calibration code of the target RF chain may correspond to a phase difference other than 90 °.

First, the calibration apparatus may set the first phase code 511 in the target RF chain and measure the intensity y ₁ of the combined signal for the first phase code 511. Based on the strength y ₁ of the combined signal for the first phase code 511, the calibration apparatus may determine a phase difference between a phase corresponding to the first phase code 511 and a reference phase as shown in Equation 1 below:

은 제1 위상 코드 511에 대응하는 위상과 기준 위상간 위상 차, y₁은 제1 위상 코드 511에 대한 조합 신호의 세기,

은 기준 신호의 세기,

는 테스트 신호의 세기를 의미한다.From here,

Is the phase difference between the phase corresponding to the first phase code 511 and the reference phase, y ₁ is the strength of the combined signal for the first phase code 511,

Is the strength of the reference signal,

Denotes the strength of the test signal.

Next, the calibration apparatus may set the second phase code 513 in the target RF chain, and measure the intensity y ₂ of the combined signal for the second phase code 513. The calibration apparatus determines the phase state of the phase difference between the phase corresponding to the first phase code 511 and the reference phase as shown in Equation 2 below based on the strength y ₂ of the combined signal for the second phase code 513. You can determine the reference value for:

은 제1 위상 코드 511에 대응하는 위상과 기준 위상간 위상 차, y₂는 제2 위상 코드 513에 대한 조합 신호의 세기,

은 기준 신호의 세기,

는 테스트 신호의 세기,

는 위상 차

의 위상 상태를 결정하기 위한 기준 값을 의미한다. 만약,

>0인 경우, 제1 위상 코드 511에 대응하는 위상은 기준 위상보다 지연된다.

<0인 경우, 제1 위상 코드 511에 대응하는 위상은 기준 위상보다 선행한다. From here,

Is the phase difference between the phase corresponding to the first phase code 511 and the reference phase, y ₂ is the strength of the combined signal for the second phase code 513,

Is the strength of the reference signal,

Is the strength of the test signal,

Phase difference

Means a reference value for determining the phase state. if,

If> 0, the phase corresponding to the first phase code 511 is delayed than the reference phase.

If <0, the phase corresponding to the first phase code 511 precedes the reference phase.

The calibration apparatus may determine a phase corresponding to the first candidate code 521 as shown in Equation 3 below based on the phase difference between the phase corresponding to the first phase code 511 and the reference phase and the phase state of the phase difference. have:

은 제1 후보 코드 521에 대응하는 위상,

는 제1 위상 코드 511에 대응하는 위상,

은 제1 위상 코드 511에 대응하는 위상과 기준 위상간 위상 차를 의미한다. <수학식 3>에서, 제1 위상 코드 511에 대응하는 위상이 기준 위상보다 지연될 경우, '+' 부호가 적용된다. 반면, 제1 위상 코드 511에 대응하는 위상이 기준 위상보다 선행할 경우, '-'부호가 적용된다. 제1 후보 코드 521은 위상

과 제1 후보 코드 521간 대응 관계를 이용하여 결정될 수 있다.From here,

Is the phase corresponding to the first candidate code 521,

Is a phase corresponding to the first phase code 511,

Denotes a phase difference between a phase corresponding to the first phase code 511 and a reference phase. In Equation 3, when the phase corresponding to the first phase code 511 is delayed than the reference phase, a '+' sign is applied. On the other hand, when the phase corresponding to the first phase code 511 precedes the reference phase, a '-' sign is applied. First candidate code 521 is phase

And the first candidate code 521 may be determined using the corresponding relationship.

In addition, the calibration apparatus may determine a phase difference between the phase corresponding to the second phase code 513 and the reference phase as shown in Equation 4 below based on the strength y ₂ of the combined signal for the second phase code 513. :

는 제2 위상 코드 513에 대응하는 위상과 기준 위상간 위상 차, y₂는 제2 위상 코드 513에 대한 조합 신호의 세기,

은 기준 신호의 세기,

는 테스트 신호의 세기를 의미한다. 본 예시에서,

=

+90°의 관계가 성립한다.From here,

Is the phase difference between the phase corresponding to the second phase code 513 and the reference phase, y ₂ is the strength of the combined signal for the second phase code 513,

Is the strength of the reference signal,

Denotes the strength of the test signal. In this example,

=

A relationship of + 90 ° holds.

Next, the calibration apparatus may set the third phase code 515 in the target RF chain and measure the intensity y ₃ of the combined signal for the third phase code 515. The calibration apparatus determines the phase state of the phase difference between the phase corresponding to the second phase code 513 and the reference phase as shown in Equation 5 below based on the strength y ₃ of the combined signal for the third phase code 515. You can determine the reference value for:

는 제2 위상 코드 513에 대응하는 위상과 기준 위상간 위상 차, y₃은 제3 위상 코드 515에 대한 조합 신호의 세기,

은 기준 신호의 세기,

는 테스트 신호의 세기,

는 위상 차

의 위상 상태를 결정하기 위한 기준 값을 의미한다. 만약,

>0인 경우, 제2 위상 코드 513에 대응하는 위상은 기준 위상보다 지연된다.

<0인 경우, 제2 위상 코드 513에 대응하는 위상은 기준 위상보다 선행한다.From here,

Is the phase difference between the phase corresponding to the second phase code 513 and the reference phase, y ₃ is the strength of the combined signal for the third phase code 515,

Is the strength of the reference signal,

Is the strength of the test signal,

Phase difference

Means a reference value for determining the phase state. if,

If> 0, the phase corresponding to the second phase code 513 is delayed than the reference phase.

If <0, the phase corresponding to the second phase code 513 precedes the reference phase.

The calibration apparatus may determine a phase corresponding to the second candidate code 523 as shown in Equation 6 below based on the phase difference between the phase corresponding to the second phase code 513 and the reference phase and the phase state of the phase difference. have;

는 제2 후보 코드 523에 대응하는 위상,

은 제2 위상 코드 513에 대응하는 위상,

는 제2 위상 코드 513에 대응하는 위상과 기준 위상간 위상 차,

는 제1 위상 코드 511에 대응하는 위상을 의미한다. <수학식 6>에서, 제2 위상 코드 513에 대응하는 위상이 기준 위상보다 지연될 경우, '+'부호가 적용된다. 반면, 제2 위상 코드 513에 대응하는 위상이 기준 위상보다 선행할 경우, '-'부호가 적용된다. 제2 후보 코드 523은 위상

와 제2 후보 코드 523간 대응 관계를 이용하여 결정될 수 있다.From here,

Is the phase corresponding to the second candidate code 523,

Is the phase corresponding to the second phase code 513,

Is the phase difference between the phase corresponding to the second phase code 513 and the reference phase,

Denotes a phase corresponding to the first phase code 511. In Equation 6, when the phase corresponding to the second phase code 513 is delayed than the reference phase, a '+' sign is applied. On the other hand, if the phase corresponding to the second phase code 513 precedes the reference phase, a '-' sign is applied. Second candidate code 523 is phase

And the second candidate code 523 may be determined using the corresponding relationship.

In the above examples, three phase codes (eg, first phase code 511, second phase code 513,) to estimate two candidate codes (eg, first candidate code 521, second candidate code 523) Although third phase code 515 is used, this is exemplary and more than three phase codes may be used. For example, since two phase codes are set in the target RF chain in order to estimate each candidate code, measurement of the strength of the combined signal for the two phase codes is required, so four phases are estimated to estimate the two candidate codes. Codes can be used. In addition, although two candidate codes are estimated in the above-described examples, more than two candidate codes may be estimated.

6 illustrates a flowchart for determining an error for a candidate code according to various embodiments of the present disclosure. 6 illustrates a method of operating the calibration device 200. In FIG. 6, it is assumed that the first candidate code and the second candidate code for the calibration code of the target RF chain are estimated based on the phase codes set in the target RF chain.

Referring to FIG. 6, in step 601, the calibration apparatus estimates the strength of the combined signal estimated for the phase codes under the condition that the first candidate code corresponds to the reference phase, and the three periods of the combined signal measured for the phase codes. Determine the first error. In other words, the calibration device may determine an error for the estimated first candidate code. When the calibration apparatus assumes that the reference phase corresponds to the first candidate code (i.e., it is unknown whether the reference phase actually corresponds to the first candidate code), the theoretical theoretical strength of the combined signal for each phase code is calculated. It can be estimated. In addition, the calibration apparatus may measure the strength of the combined signal for each phase code to obtain the measured strength of the combined signal. The calibration apparatus may determine the strength of the theoretically estimated combined signal for each phase code and the three-period first error of the actually measured combined signal.

In operation 603, the calibration apparatus determines the strength of the combined signal estimated for the phase codes and the three-time second error of the combined signal measured for the phase codes under the condition that the second candidate code corresponds to the reference phase. . In other words, the calibration device may determine an error for the estimated second candidate code. The calibration apparatus may determine the second error using a method similar to the method of determining the first error.

In operation 605, the calibration apparatus determines whether the first error is smaller than the second error. In other words, the calibration apparatus may compare the first error with respect to the first candidate code and the second error with respect to the second candidate code.

If the first error is smaller than the second error, in operation 607, the calibration apparatus determines the first candidate code as the calibration code. In other words, if the first error for the first candidate code is smaller than the second error for the second candidate code, the calibration apparatus is less than the phase corresponding to the second candidate code. It may be determined that it is closer, and the first candidate code may be determined as a calibration code.

If the first error is greater than the second error, in step 609, the calibration apparatus determines the second candidate code as the calibration code. In other words, if the second error for the second candidate code is smaller than the first error for the first candidate code, the calibration apparatus may be configured to have a phase corresponding to the second candidate code to a reference phase than the phase corresponding to the first candidate code. It may be determined that it is closer, and the second candidate code may be determined as a calibration code.

Although not shown, the calibration apparatus may apply the determined calibration code to the target RF chain to complete calibration on the target RF chain.

7A and 7B illustrate graphs showing errors for estimated candidate codes according to various embodiments of the present disclosure. In graphs 710 and 720 of FIGS. 7A and 7B, the horizontal axis represents a phase corresponding to the phase code set in the target RF chain, and the vertical axis represents the strength of the combined signal. 7A and 7B, the first candidate code 521 is estimated based on the first phase code 511 and the second phase code 513 set in the target RF chain, and the second phase code 513 and third phase code 515 set in the target RF chain. It is assumed that the second candidate code 523 was estimated based on.

Referring to FIG. 7A, in graph 710, a function of the combined signal strength for the first candidate code 521 and a function of the combined signal strength for the second candidate code 523 is shown. According to various embodiments of the present disclosure, the function of the combined signal strength for the first candidate code 521 is the strength of the combined signal for the possible phase codes of the target RF chain under the condition that the first candidate code 521 corresponds to the reference phase. Means a function of. In other words, the function of the combined signal strength for the first candidate code 521 is assuming that the first candidate code 521 corresponds to the reference phase (ie, it is not known whether the first candidate code 521 actually corresponds to the reference phase). ), A function of the strength of the combined signal for the possible phase codes of the target RF chain. The function of the combined signal strength for the second candidate code 523 may also be defined in a similar way.

More specifically, the function of the combined signal strength for the first candidate code 521 can be expressed as Equation 7 below:

는 제1 후보 코드 521에 대한 조합 신호 세기의 함수,

은 제1 후보 코드 521에 대응하는 위상,

는 대상 RF 체인에 설정된 위상 코드에 대응하는 위상,

은 기준 신호의 세기,

는 테스트 신호의 세기를 의미한다.

는 0°부터 360°의 범위 이내에서 존재한다.From here,

Is a function of the combined signal strength for the first candidate code 521,

Is the phase corresponding to the first candidate code 521,

Is the phase corresponding to the phase code set in the target RF chain,

Is the strength of the reference signal,

Denotes the strength of the test signal.

Is within the range of 0 ° to 360 °.

Similarly, the function of the combined signal strength for the second candidate code 523 can be expressed as Equation 8 below:

는 제2 후보 코드 523에 대한 조합 신호 세기의 함수,

는 제2 후보 코드 523에 대응하는 위상,

는 대상 RF 체인에 설정된 위상 코드에 대응하는 위상,

은 기준 신호의 세기,

는 테스트 신호의 세기를 의미한다.

는 0°부터 360°의 범위 이내에서 존재한다.From here,

Is a function of the combined signal strength for the second candidate code 523,

Is the phase corresponding to the second candidate code 523,

Is the phase corresponding to the phase code set in the target RF chain,

Is the strength of the reference signal,

Denotes the strength of the test signal.

Is within the range of 0 ° to 360 °.

이고, 제2 위상 코드 513에서 제1 후보 코드 521에 대한 조합 신호 세기의 함수의 값은

이고, 제3 위상 코드 515에서 제1 후보 코드 521에 대한 조합 신호 세기의 함수의 값은

로 표현될 수 있다. 여기에서,

는 제1 후보 코드 521에 대한 조합 신호 세기의 함수,

은 제1 후보 코드 521에 대응하는 위상,

는 제1 위상 코드 511에 대응하는 위상을 의미한다.Referring to FIG. 7B, an error with respect to the first candidate code 521 and an error with respect to the second candidate code 523 are shown in graph 720. The error for the first candidate code 521 is the strength of the combined signal estimated for the phase codes under the condition that the first candidate code 521 corresponds to the reference phase, and the three period error of the combined signal measured for the phase codes. Can be. For example, the strength of the combined signal measured for the first phase code 511 is y ₁ , the strength of the combined signal measured for the second phase code 513 is y ₂ , and the measured combination for the third phase code 515. The strength of the signal may be y ₃ . The strength of the combined signal estimated for the phase codes under the condition that the first candidate code 521 corresponds to the reference phase may be a value of a function of the combined signal strength for the first candidate code 521 in the phase codes. For example, the value of the function of the combined signal strength from the first phase code 511 to the first candidate code 521 is

The value of the function of the combined signal strength for the first candidate code 521 in the second phase code 513 is

And the value of the function of the combined signal strength for the first candidate code 521 in the third phase code 515 is

It can be expressed as. From here,

Is a function of the combined signal strength for the first candidate code 521,

Is the phase corresponding to the first candidate code 521,

Denotes a phase corresponding to the first phase code 511.

이고, 제2 위상 코드 513에서 제2 후보 코드 523에 대한 조합 신호 세기의 함수의 값은

이고, 제3 위상 코드 515에서 제2 후보 코드 523에 대한 조합 신호 세기의 함수의 값은

로 표현될 수 있다. 여기에서,

는 제1 후보 코드 521에 대한 조합 신호 세기의 함수,

는 제2 후보 코드 523,

는 제1 위상 코드 511에 대응하는 위상을 의미한다.Similarly, the error for the second candidate code 523 is determined by the strength of the combined signal estimated for the phase codes under the condition that the second candidate code 523 corresponds to the reference phase and the combined signal measured for the phase codes. It may be a period error. The strength of the combined signal estimated for the phase codes under the condition that the second candidate code 523 corresponds to the reference phase may be a value of the combined signal strength function for the second candidate code 523 in the phase codes. For example, the value of the function of the combined signal strength from the first phase code 511 to the second candidate code 523 is

And the value of the function of the combined signal strength for the second candidate code 523 in the second phase code 513 is

And the value of the function of the combined signal strength for the second candidate code 523 in the third phase code 515 is

It can be expressed as. From here,

Is a function of the combined signal strength for the first candidate code 521,

Is the second candidate code 523,

Denotes a phase corresponding to the first phase code 511.

Based on the above result, an error for the first candidate code 521 may be expressed as Equation 9 below:

은 제1 후보 코드 521에 대한 오차,

은 위상 코드들에 대해 측정된 신호 세기 벡터(이하, '측정된 신호 세기 벡터'로 지칭된다),

은 제1 후보 코드 521이 기준 위상에 대응한다는 조건 하에서 위상 코드들에 대해 추정된 신호 세기 벡터(이하, '제1 후보 코드 521과 관련된 신호 세기 벡터'로 지칭된다)를 의미한다.From here,

Is the error for first candidate code 521,

Is the signal strength vector measured for the phase codes (hereinafter referred to as the 'measured signal strength vector'),

Denotes a signal strength vector estimated for the phase codes under the condition that the first candidate code 521 corresponds to the reference phase (hereinafter, referred to as a 'signal strength vector associated with the first candidate code 521').

An error with respect to the second candidate code 523 may be expressed as Equation 10 below:

는 제2 후보 코드 523에 대한 오차,

은 위상 코드들에 대해 측정된 신호 세기 벡터,

은 제2 후보 코드 523이 기준 위상에 대응한다는 조건 하에서 위상 코드들에 대해 추정된 신호 세기 벡터(이하, '제2 후보 코드 523과 관련된 신호 세기 벡터'로 지칭된다)를 의미한다.From here,

Is the error for the second candidate code 523,

Is the signal strength vector measured for the phase codes,

Denotes a signal strength vector estimated for the phase codes under the condition that the second candidate code 523 corresponds to the reference phase (hereinafter, referred to as a 'signal strength vector associated with the second candidate code 523').

는 하기의 <수학식 11>과 같이 표현될 수 있다:Signal strength vector measured for phase codes

May be expressed as Equation 11 below:

은 위상 코드들에 대해 측정된 신호 세기 벡터, y₁은 제1 위상 코드 511에 대해 측정된 조합 신호의 세기, y₂는 제2 위상 코드 513에 대해 측정된 조합 신호의 세기, y₃은 제3 위상 코드 515에 대해 측정된 조합 신호의 세기를 의미한다.From here,

Is the signal strength vector measured for the phase codes, y ₁ is the strength of the combined signal measured for the first phase code 511, y ₂ is the strength of the combined signal measured for the second phase code 513, and y ₃ is The strength of the combined signal measured for the three phase code 515.

은 하기의 <수학식 12>와 같이 표현될 수 있다:Estimated signal strength vector for phase codes under the condition that the first candidate code 521 corresponds to the reference phase

May be expressed as Equation 12 below:

은 제1 후보 코드 521이 기준 위상에 대응한다는 조건 하에서 위상 코드들에 대해 추정된 신호 세기 벡터,

은 제1 후보 코드 521에 대응하는 위상,

는 제1 위상 코드 511에 대응하는 위상,

는 제1 후보 코드 521이 기준 위상에 대응한다는 조건 하에서 제1 위상 코드 511에 대해 추정된 조합 신호의 세기,

는 제1 후보 코드 521이 기준 위상에 대응한다는 조건 하에서 제2 위상 코드 513에 대해 추정된 조합 신호의 세기,

은 제1 후보 코드 521이 기준 위상에 대응한다는 조건 하에서 제3 위상 코드 515에 대해 추정된 조합 신호의 세기를 의미한다. From here,

Is an estimated signal strength vector for the phase codes under the condition that the first candidate code 521 corresponds to the reference phase,

Is the phase corresponding to the first candidate code 521,

Is a phase corresponding to the first phase code 511,

Is the strength of the combined signal estimated for the first phase code 511 under the condition that the first candidate code 521 corresponds to the reference phase,

Is the strength of the combined signal estimated for the second phase code 513 under the condition that the first candidate code 521 corresponds to the reference phase,

Denotes the strength of the combined signal estimated for the third phase code 515 under the condition that the first candidate code 521 corresponds to the reference phase.

은 하기의 <수학식 13>와 같이 표현될 수 있다:Similarly, the estimated signal strength vector for the phase codes under the condition that the second candidate code 523 corresponds to the reference phase

May be expressed as Equation 13 below:

은 제2 후보 코드 523이 기준 위상에 대응한다는 조건 하에서 위상 코드들에 대해 추정된 신호 세기 벡터,

는 제2 후보 코드 523,

는 제1 위상 코드 511에 대응하는 위상,

는 제2 후보 코드 523이 기준 위상에 대응한다는 조건 하에서 제1 위상 코드 511에 대해 추정된 조합 신호의 세기,

는 제2 후보 코드 523이 기준 위상에 대응한다는 조건 하에서 제2 위상 코드 513에 대해 추정된 조합 신호의 세기,

은 제2 후보 코드 523이 기준 위상에 대응한다는 조건 하에서 제3 위상 코드 515에 대해 추정된 조합 신호의 세기를 의미한다. From here,

Is an estimated signal strength vector for the phase codes under the condition that the second candidate code 523 corresponds to the reference phase,

Is the second candidate code 523,

Is a phase corresponding to the first phase code 511,

Is the intensity of the combined signal estimated for the first phase code 511 under the condition that the second candidate code 523 corresponds to the reference phase,

Is the strength of the combined signal estimated for the second phase code 513 under the condition that the second candidate code 523 corresponds to the reference phase,

Denotes the strength of the combined signal estimated for the third phase code 515 under the condition that the second candidate code 523 corresponds to the reference phase.

In the above examples, the error is expressed in least square error (LSE), but this is exemplary, and the error is the difference in the three periods of the combined signal measured for the phase codes and the strength of the combined signal estimated for the phase codes. It can also be expressed as a sum of all of them. As another example, the error may be determined based on the strength of the combined signal estimated for the phase codes and the correlation coefficient of the combined signal measured for the phase codes. The calibration apparatus may determine a correlation coefficient for each candidate code and determine that the candidate code of the higher correlation coefficient has a lower error.

According to various embodiments of the present disclosure, the calibration device may estimate the strength of the test signal based on the strength of the combined signal measured for the phase codes. In other words, the calibration device may not directly measure the strength of the test signal, but may estimate the strength of the test signal based on the strength of the combined signal measured for the phase codes. Since the strength of the test signal cannot be properly estimated when the measurement of the signal strength is incorrect, the calibration apparatus can inversely determine whether the measurement of the signal strength is incorrect based on the validity of the estimated test signal strength.

8 illustrates examples of calibration results according to various embodiments of the present disclosure. In graphs 810 and 820, the horizontal axis represents the phase code set in the target RF chain, and the vertical axis represents the strength of the combined signal.

Referring to the graph 810, the strength of the reference signal and the strength of the test signal are similar. In other words, graph 810 shows a case where the strength of the test signal is properly estimated. If the strength of the test signal is properly estimated, it can be determined that the measurement result of the combined signal strength used to estimate the strength of the test signal is reasonable, and thus candidate codes based on the strength of the combined signal can also be estimated properly. . Thus, according to graph 810, the function of the combined signal strength for the candidate code is similar to the measured strength of the combined signal, and the error for the candidate code may be small.

Referring to graph 820, the strength of the reference signal and the strength of the test signal are quite different. In other words, graph 820 represents a case where the strength of the test signal is not properly estimated. If the strength of the test signal is not properly estimated, it may be determined that the measurement result of the combined signal strength used to estimate the strength of the test signal is not valid, and thus candidate codes based on the strength of the combined signal may also be appropriately estimated. Can't. Thus, according to graph 820, the strength function of the combined signal for the candidate code is different from the measured strength of the combined signal, and the error for the candidate code may be large.

According to various embodiments of the present disclosure, when the RF chain is broken or phase shifter phasing (PS phasing) fails, the strength of the test signal may be incorrectly estimated. As another example, if the signal strength (e.g., the strength of the combined signal, the strength of the reference signal) is incorrectly measured, the phase code set in the target RF chain is incorrectly controlled, or the measurement setup is incorrect, the strength of the test signal Can be wrongly estimated.

In FIG. 9, the operation of the calibration device for checking whether the strength of the test signal is properly estimated is described.

9 is a flowchart for confirming the validity of the strength of an estimated test signal according to various embodiments of the present disclosure. 9 illustrates the operation of calibration device 200. In FIG. 9, it is assumed that the code difference between the first phase code and the second phase code corresponds to a phase difference of 90 °, and the code difference between the second phase code and the third phase code corresponds to the phase difference. However, this is for convenience of description, and various embodiments of the present disclosure are not limited to the code difference of 90 °.

Referring to FIG. 9, in operation 901, the calibration apparatus estimates a first candidate value for the strength of the test signal based on the strength of the combined signal for the first phase code and the strength of the combined signal for the third phase code. do. For example, the first candidate value for the strength of the test signal may be estimated as in Equation 14 below:

는 테스트 신호에 대한 제1 후보 값, y₁은 제1 후보 코드에 대해 측정된 조합 신호의 세기, y₃은 제3 후보 코드에 대해 측정된 조합 신호의 세기,

은 기준 신호의 세기를 의미한다.From here,

Is the first candidate value for the test signal, y ₁ is the strength of the combined signal measured for the first candidate code, y ₃ is the strength of the combined signal measured for the third candidate code,

Denotes the strength of the reference signal.

In operation 903, the calibration apparatus estimates a second candidate value for the strength of the test signal based on the strength of the combined signal for the first phase code and the strength of the combined signal for the third phase code. For example, the second candidate value for the strength of the test signal may be estimated based on Equation 1 and Equation 2.

In operation 905, the calibration apparatus estimates a third candidate value for the strength of the test signal based on the strength of the combined signal for the second phase code and the strength of the combined signal for the third phase code. For example, the third candidate value for the strength of the test signal may be estimated based on Equation 4 and Equation 5.

In operation 907, the calibration apparatus determines whether a condition associated with the estimated candidate values is satisfied. For example, the condition associated with the candidate values may include a first condition that the difference between the estimated candidate values is less than or equal to the threshold value X ₃ . As another example, the condition associated with the candidate values may include a second condition that the difference between the three estimated periods of each of the estimated candidate values and the reference signal is less than or equal to the threshold value X ₄ . The condition associated with the candidate values may include at least one of the first condition and the second condition described above. Threshold X ₃ and threshold X- ₄ may be determined based on the gain and / or desired performance designed for each RF chain. For example, if each RF chain is designed to have a gain of 30 dBm, the threshold value X ₃ may be 5 dB and the threshold value X ₄ may be 7 dB. The values of X ₃ and X-- ₄ described above are exemplary and various modifications are possible. In addition, the threshold values X ₃ and X − ₄ may be preset values.

If the condition associated with the candidate values is satisfied, in step 909, the calibration apparatus estimates candidate codes for the calibration code of the target RF chain based on the strength of the combined signal for the phase codes. For example, the calibration apparatus may estimate candidate codes according to Equations 1 to 6.

If the condition associated with the candidate values is not satisfied, the calibration device ends the present algorithm. As another example, the calibration apparatus may return to step 901 to estimate the candidate values for the strength of the test signal again or to measure the strength of the combined signal for the phase codes again.

According to various embodiments of the present disclosure, the calibration apparatus may estimate the plurality of candidate codes for the calibration code of the target RF chain by measuring the strength of the combined signal with respect to the plurality of phase codes. Since the candidate code cannot be estimated properly when the measurement of the signal strength is wrong, the calibration apparatus may determine whether the measurement of the signal strength is wrong based on the validity of the estimated candidate codes.

10A and 10B show other examples of calibration results according to various embodiments of the present disclosure. In graphs 1010 and 1020, the horizontal axis represents the phase code set in the target RF chain, and the vertical axis represents the strength of the combined signal.

Referring to FIG. 10A, in graph 1010, the function of the combined signal strength for the first candidate code and the function of the combined signal strength for the second candidate code are similar. In other words, the first candidate code and the second candidate code are similar, and the code difference between the first candidate code and the second candidate code may be relatively small (eg, within a 2-code difference). In this case, it may be determined that the first candidate code and the second candidate code are properly estimated.

Referring to FIG. 10B, in graph 1020, the function of the combined signal strength for the first candidate code and the function of the combined signal strength for the second candidate code are quite different. In other words, the first candidate code and the second candidate code are quite different, and the code difference between the first candidate code and the second candidate code may be relatively large (eg, 3-code difference). In this case, it may be determined that the first candidate code and the second candidate code were not properly estimated.

According to various embodiments of the present disclosure, when an RF chain fails or phase converter paging fails, a candidate code may be incorrectly estimated. As another example, the candidate code may be incorrectly estimated if the signal strength (e.g., the strength of the combined signal, the strength of the reference signal) is incorrectly measured, the phase code set in the target RF chain is incorrectly controlled, or the measurement setting is incorrect. .

When the calibration apparatus sets a calibration code determined among wrongly estimated candidate codes in the target RF chain, the beam in the length direction may not be properly generated by the phased array antenna. Therefore, the operation of the calibration apparatus to check whether the candidate code is properly estimated is required, which will be described in more detail in FIG. 11 below.

11 illustrates a flowchart for confirming validity of an estimated candidate code according to various embodiments of the present disclosure. 11 illustrates an operation of the calibration device 200.

Referring to FIG. 11, in operation 1101, the calibration apparatus determines whether a code difference between a first candidate code and a second candidate code is equal to or less than a threshold value X ₅ . As another example, the calibration apparatus may determine whether a phase difference between a phase corresponding to the first candidate code and a phase corresponding to the second candidate code is equal to or less than a threshold value X ₅ . According to various embodiments of the present disclosure, the threshold value X ₅ may be set to ensure the performance of the phased array antenna after calibration. For example, if the threshold X ₅ -corresponds to 60 °, then the phase error of the RF chain (ie, the phase corresponding to the code difference between the calibration code of the RF chain and the phase code currently set in the RF chain) is up to 60 °. And the direction or pattern of the beam formed by the phased array antenna may be severely distorted. Thus, the threshold value X _5- may correspond to an angle smaller than 60 ° (eg 45 °). The value of X ₅ described above is exemplary, and various modifications are possible. In addition, the threshold value X ₅ may be a preset value.

If the code difference between the first candidate code and the second candidate code is equal to or less than the threshold value X ₅ , in operation 1103, the calibration apparatus determines one of the first candidate code and the second candidate code as the calibration code. For example, the calibration apparatus may compare the error for the first candidate code with the error for the second candidate code and determine a candidate code having a smaller error as the calibration code.

If the code difference between the first candidate code and the second candidate code exceeds a threshold value X ₅ , the calibration device ends the present algorithm. As another example, the calibration apparatus may estimate the first candidate code and the second candidate code again, or measure the strength of the combined signal for the phase codes again, and then perform operations 1101 and subsequent operations.

12 is a diagram 1200 illustrating a relationship between a validity of an estimated test signal strength and a validity of an estimated candidate code, according to various embodiments of the present disclosure.

Referring to FIG. 12, the validity of the estimated test signal strength may be a necessary condition for the estimated candidate code to be valid. In other words, for the estimated candidate code to be valid, the strength of the estimated test signal is required to be valid. If the strength of the estimated test signal is not valid, the estimated candidate code may also be invalid.

In the above examples, the calibration apparatus estimates the strength and candidate code of the test signal and determines whether the strength and candidate code of the estimated test signal are valid. In addition, the calibration apparatus according to various embodiments of the present disclosure may measure the strength of the reference signal and determine whether the measured reference signal is reasonable. The operation of the calibration device to determine the validity of the measured reference signal strength is described in greater detail below in FIG. 13.

13 is a flowchart for determining the validity of the strength of a reference signal measured according to various embodiments of the present disclosure. 13 illustrates an operation of the calibration device 200.

Referring to FIG. 13, in operation 1301, the calibration apparatus measures the intensity of a reference signal. The calibration apparatus may turn on only the reference RF chain and turn off the remaining RF chains of the phased array antenna to measure the strength of the reference signal. At this time, an arbitrary phase code may be set in the reference RF chain.

In operation 1303, the calibration apparatus determines whether the measured reference signal strength is between a threshold value X ₁ and a threshold value X ₂ . Threshold X ₁ and threshold X _2- may be determined based on the gain, maximum gain offset, and / or required performance designed for each RF chain. For example, if each RF chain is designed to have a gain of 30 dBm and the maximum gain offset is 3 dB, the reference signal strength should be between 27 dBm and 33 dBm. Therefore, in this case, the threshold value X ₁ may be 27 dBm, and the threshold value X ₂ may be 33 dBm. The values of X ₁ and X ₂ described above are exemplary, and various modifications are possible. Further, the threshold value X ₁ and X-- _2- may be a value set in advance.

If the measured reference signal strength is between the threshold value X ₁ and the threshold value X ₂ , in step 1305, the calibration device measures the strength of the combined signal for the phase codes set in the target RF chain based on the reference signal. do. In other words, if it is determined that the strength of the measured reference signal is reasonable, the calibration device may measure the strength of the combined signal of the test signal for the reference signal and the phase codes.

If the measured intensity of the reference signal is not between the threshold value X ₁ and the threshold value X ₂ , the calibration device ends the present algorithm. As another example, the calibration apparatus may return to step 1301 to measure the strength of the reference signal again.

14 is a flowchart illustrating overall operations of a calibration device according to various embodiments of the present disclosure. A flowchart is shown. 14 illustrates the operation of calibration device 200.

Referring to FIG. 14, in operation 1401, the calibration apparatus measures the intensity of a reference signal. The calibration apparatus may turn on only the reference RF chain and turn off the remaining RF chains of the phased array antenna to measure the strength of the reference signal. At this time, an arbitrary phase code may be set in the reference RF chain.

In operation 1403, the calibration apparatus determines whether the measured reference signal strength is between a threshold value X ₁ and a threshold value X ₂ . Threshold X ₁ and threshold X _2- may be determined based on the gain, maximum gain offset, and / or required performance designed for each RF chain. As another example, the threshold value X ₁ and the threshold value X _2- may be predetermined values.

If the strength of the measured reference signal is between the threshold value X ₁ and the threshold value X ₂ , in step 1405, the calibration device turns on the target RF chain. The calibration device turns on (eg, bias current and / or voltage supply) the target RF chain to calibrate the target RF chain based on the reference signal when the measured reference signal strength is reasonable.

If the measured reference signal strength is between the threshold value X ₁ and the threshold value X ₂ , in step 1435, the calibration device determines that a fail code (ie, an incorrect calibration code) will be estimated. As another example, the calibration apparatus may return to step 1401 and measure the strength of the reference signal again.

In operation 1407, the calibration apparatus sets respective phase codes in the target RF chain, and measures the strength of the combined signal for each phase code. For example, the calibration apparatus may set the first phase code in the target RF chain to measure the strength of the combined signal for the first phase code. The calibration apparatus may set the second phase code in the target RF chain to measure the strength of the combined signal for the second phase code. The third phase code may be set in the target RF chain to measure the strength of the combined signal with respect to the third phase code. For convenience of explanation, it is assumed that the code difference between the first phase code and the second phase code corresponds to 90 ° and the code difference between the second phase code and the third phase code corresponds to 90 °. However, this is exemplary and various modifications to the code difference are possible.

In operation 1409, the calibration apparatus estimates a candidate value for the strength of the test signal. For example, the calibration device may measure the strength of the combined signal measured in operation 1407 according to Equation 14, Equation 1, Equation 2, Equation 4, and / or Equation 5, respectively. Can be used to estimate candidate values for the strength of the test signal.

In operation 1411, the calibration apparatus determines whether the difference between the estimated candidate values is less than or equal to the threshold value X ₃ . Threshold X ₃ may be determined based on the gain and / or required performance designed for each RF chain. As another example, the threshold value X ₃ may be a predetermined value. If the difference between the estimated candidate values is not less than or equal to the threshold value X ₃ , in step 1435, the calibration device determines that an error code will be estimated. As another example, the calibration apparatus may return to step 1409 to re-estimate candidate values for the strength of the test signal, or to return to step 1407 to measure the strength of the combined signal for the phase codes again.

If the difference between the estimated candidate values is less than or equal to the threshold value X ₃ , in step 1413, the calibration apparatus determines whether the three-term difference between the estimated candidate value and the measured reference signal is less than or equal to the threshold value X ₄ . The threshold value X ₄ may be determined based on the gain and / or required performance designed for each RF chain. As another example, the threshold value X ₄ may be a predetermined value. If the three-time difference between the estimated candidate value and the measured reference signal is not less than or equal to the threshold value X ₄ , in step 1435, the calibration device determines that an error code will be estimated. As another example, the calibration apparatus may return to step 1409 to re-estimate candidate values for the strength of the test signal, or to return to step 1407 to measure the strength of the combined signal for the phase codes again.

If the three-time difference between the estimated candidate value and the measured reference signal is less than or equal to the threshold value X ₄ , in operation 1415, the calibration apparatus estimates candidate codes for the calibration code of the target RF chain. The calibration apparatus may determine the phase difference between the phase and the reference phase and the phase difference corresponding to the phase code based on the strength of the combined signal for the phase codes, and the candidate based on the phase difference and the phase state of the phase difference. The code can be estimated. For example, the calibration apparatus may estimate the first candidate code based on the first phase code and the second phase code, and may estimate the second candidate code based on the second phase code and the third phase code. .

In operation 1417, the calibration apparatus determines whether a code difference between candidate codes is equal to or less than a threshold value X ₅ . The threshold value X ₅ may be set to ensure the performance of the phased array antenna after calibration. Alternatively, the threshold value X ₅ may be a preset value. For example, the calibration apparatus may determine whether a code difference between the first candidate code and the second candidate code is equal to or less than a threshold value X ₅ . As another example, the calibration apparatus may determine whether a phase difference between a phase corresponding to the first candidate code and a phase corresponding to the second candidate code is equal to or less than a threshold value X ₅ . If the code difference between the candidate codes is not less than or equal to the threshold value X ₅ , in step 1435, the calibration device may determine that an error code will be estimated. As another example, the calibration apparatus may return to step 1415 to estimate the candidate codes again, or to return to step 1407 to measure the strength of the combined signal for the phase codes again.

If the code difference between the candidate codes is less than or equal to the threshold value X ₅ , in step 1421, the calibration apparatus determines a function of the combined signal strength for each candidate code. For example, the calibration device may generate a function of the combined signal strength for the first candidate code and generate the function of the combined signal strength for the second candidate code.

In operation 1423, the calibration apparatus determines signal strength vectors. For example, the calibration device may measure the signal strength vector measured for the phase codes (ie, the measured signal strength vector) and the estimated signal strength vector for the phase codes under the condition that the first candidate code corresponds to the reference phase. (Ie, a signal strength vector associated with the first candidate code) and a signal strength vector estimated for the phase codes under the condition that the second candidate code corresponds to the reference phase (ie, signal strength vector associated with the second candidate code). Can be determined. To determine the signal strength vector associated with the first candidate code and the signal strength vector associated with the second candidate code, the function of the combined signal strength determined in step 1421 may be used.

In step 1425, the calibration unit determines whether or not smaller than the errors of the first candidate code (that is, _can1 LSE) is an error (that is, _can2 LSE) for the second candidate code. In other words, the calibration apparatus may compare the error for the first candidate code with the error for the second candidate code.

The error is less than (i.e., _can2 LSE) for the error (that is, LSE _can1) and the second candidate code for the first candidate code, at step 1427, the calibration device determines the first candidate code by the calibration code. In the case of not less than one candidate error in the code (i.e., LSE _can1) and the second error (that is, LSE _can2) for the candidate code, at step 1429, the calibration device determines the second candidate code by the calibration code. In other words, the calibration apparatus may determine a candidate code having a smaller error among the estimated candidate codes as the calibration code.

In operation 1431, the calibration apparatus determines whether all RF chains have been calibrated. In other words, the calibration device determines whether there is at least one uncalibrated RF chain among all the RF chains of the phased array antenna. If all RF chains are calibrated, the calibration device terminates this algorithm. If all the RF chains are not calibrated, in step 1433, the calibration device changes the target RF chain and returns to step 1405 to perform steps 1405 and subsequent to the changed target RF chain. That is, the calibration apparatus selects an RF chain that has not been calibrated, and performs operations for calibrating the selected RF chain.

In the above examples, two candidate codes (eg, first candidate code, second candidate code) were considered to determine a calibration code. However, according to various embodiments of the present disclosure, an additional candidate code may be considered in addition to the two candidate codes to determine a calibration code. This additional candidate code may be estimated based on the strength of the combined signal measured for the phase codes, similar to the method of estimating the first candidate code and the second candidate code. As another example, the additional candidate code may be derived from the first candidate code and the second candidate code. For example, the additional candidate code may be determined as a phase code within a threshold code difference from the first candidate code and / or the second candidate code. The calibration device can more accurately determine the calibration code by considering the error for the additional candidate code.

Hereinafter, a method of determining a calibration code based on an error for an additional candidate code will be described with reference to FIG. 15.

15 is a flowchart for determining a calibration code in consideration of an additional candidate code according to various embodiments of the present disclosure. 15 illustrates an operation of the calibration device 200.

Referring to FIG. 15, in operation 1501, the calibration apparatus determines an additional candidate code within a threshold code difference from the candidate code. As another example, the calibration device may determine an additional candidate code corresponding to a phase within a threshold phase from a phase corresponding to the candidate code. According to various embodiments of the present disclosure, the threshold code difference may be a threshold value X ₅ , and the threshold phase may be a phase (eg, 45 °) corresponding to the threshold value X ₅ . For example, if the number of possible phase codes of the target RF chain is 16, one code difference corresponds to 360/16 = 22.5 °, and therefore, if the threshold phase is 45 °, the threshold code difference may be two code differences. The values of the threshold code difference and the threshold phase described above are exemplary and various modifications are possible.

In operation 1503, the calibration apparatus determines a calibration code based on an error for the additional candidate code. The calibration device estimates the strength of the combined signal estimated for the phase codes under the condition that the additional candidate code corresponds to the reference phase, and the three-term error of the combined signal measured for the phase codes (ie, error for the additional candidate code). Can be determined. The calibration apparatus may compare the error for the additional candidate code with the error for other candidate codes, and determine the candidate code having the smallest error as the calibration code.

16 is a graph illustrating a function of combined signal strength for an additional candidate code according to various embodiments of the present disclosure. In the graph 1600 of FIG. 16, the horizontal axis represents a phase corresponding to the phase code set in the target RF chain, and the vertical axis represents the strength of the combined signal.

Referring to FIG. 16, the first additional candidate code may be derived from the first candidate code. For example, the first additional candidate code may be a code corresponding to a phase smaller than the phase of the first candidate code within a threshold code difference from the first candidate code. Thus, in graph 1600, a function of the strength of the combined signal for the possible phase codes of the target RF chain under the condition that the first additional candidate code corresponds to the reference phase (ie, the function of the combined signal strength for the first additional candidate code). ) Is adjacent to the function of the combined signal strength for the first candidate code and is located to the left of the function of the combined signal strength for the first candidate code.

Similarly, the second additional candidate code can be derived from the second candidate code. For example, the second additional candidate code may be a code corresponding to a phase greater than the phase of the second candidate code within a threshold code difference from the second candidate code. Thus, in graph 1600, a function of the strength of the combined signal for the possible phase codes of the target RF chain under the condition that the second additional candidate code corresponds to the reference phase (ie, the function of the combined signal strength for the second additional candidate code). ) Is adjacent to the function of the combined signal strength for the second candidate code and is located to the right of the function of the combined signal strength for the second candidate code.

The calibration device may determine a signal strength vector associated with the first additional candidate code based on a function of the combined signal strength for the first additional candidate code, and based on the signal strength vector associated with the first additional candidate code, The error for the additional candidate code can be determined. Similarly, the calibration device may determine an error for the second additional candidate code. The calibration apparatus may determine the calibration code more accurately by considering not only errors for candidate codes but also errors for additional candidate codes.

17 illustrates phase codes set on RF chains as a result of calibration according to various embodiments of the present disclosure.

In FIG. 17, a calibration code determined in consideration of all possible phase codes of the target RF chain may be regarded as a correct calibration code. Referring to Table 1740, an error code may be estimated for RF chain 3 when the first candidate code is considered, and an error code may be estimated for RF chain 12 when the second candidate code is considered. On the other hand, if the first candidate code and the second candidate code are considered (i.e., a candidate code having a small error in consideration of the errors for the two candidate codes is selected), the error code is not estimated for any RF chain. For all RF chains, the correct calibration code can be estimated.

Graph 1710 shows a three-year relationship between the phase code set in the target RF chain and the combined signal when the RF chain 3 is the target RF chain. Referring to graph 1710, the strength of the combined signal measured for the possible phase codes of the target RF chain (ie, RF chain 3) is similar to a function of the combined signal strength for the second candidate code, but not in the first candidate code. It is not similar to the function of the combined signal strength for. In other words, the calibration code (code 4) is the same as the second candidate code (code 4), but not the same as the first candidate code (code 3). As in this example, since the first candidate code is not the same as the calibration code, when only the first candidate code is considered, an incorrect phase code may be estimated as a calibration code in some RF chains (eg, RF chain 3). .

Graph 1720 shows a three-year relationship between the phase code set in the target RF chain and the combined signal when the RF chain 10 is the target RF chain. Referring to graph 1720, the strength of the combined signal measured for the possible phase codes of the target RF chain (ie, RF chain 10) is a function of the combined signal strength for the first candidate code and the combination for the second candidate code. Similar to the function of signal strength. In other words, the calibration code (code 4) is the same as the first candidate code (code 4) and the second candidate code (code 4). As in this example, even if only one candidate code (eg, the first candidate code or the second candidate code) is considered, the calibration code of the RF chain (eg, RF chain 10) can be correctly estimated.

Graph 1730 shows a three-year relationship between the phase code set in the target RF chain and the combined signal when the RF chain 12 is the target RF chain. Referring to graph 1730, the strength of the combined signal measured for the possible phase codes of the target RF chain (ie, RF chain 12) is similar to a function of the combined signal strength for the first candidate code, but It is not similar to the function of the combined signal strength for. In other words, the calibration code (code 2) is the same as the first candidate code (code 2) but not the same as the second candidate code (code 0). As in this example, since the second candidate code is not the same as the calibration code, if only the second candidate code is considered, an incorrect phase code may be estimated as a calibration code in some RF chains (eg, RF chain 12). .

As in the above example, by estimating a plurality of candidate codes in consideration of at least three phase codes and estimating a calibration code based on an error for each candidate code, the calibration apparatus can more accurately estimate the calibration code. .

18 illustrates a type of calibration according to various embodiments of the present disclosure.

Referring to FIG. 18, the type of calibration may include at least one of a factory calibration 1810, an online calibration 1820, and a self calibration 1830.

Factory calibration 1810 refers to calibration when a calibration device calibrates an external phased array antenna. In this case, the calibration device may be a meter 1813. For example, the measuring instrument 1813 may have a configuration of the calibration apparatus 200 illustrated in FIG. 2A, and may calibrate a phased array antenna included in the base station / terminal 1811 using at least one of the controller 210, the transceiver 220, and the reference antenna 230. have.

On-line calibration 1820 allows the calibration device to communicate with other communication devices over a wireless channel to obtain measurement values (e.g., the strength of the combined signal, the reference signal and / or the test signal), and the phase arrangement using the measured values. It means the calibration when the antenna is calibrated. In this case, the calibration device may be a communication device (eg, base station 1821, terminal 1823), and the phased array antenna for calibration may be a phased array antenna included in the corresponding communication device. For example, the base station 1821 and the terminal 1823 may perform communication through a wireless channel to obtain a measurement value, and calibrate a phased array antenna based on the measurement value. As another example, the base station 1821 may perform communication with another base station through a wireless backhaul (eg, the wireless backhaul 1825 and / or the wireless backhaul 1827) to obtain a measurement value, and calibrate a phased array antenna based on the measurement value. For the online calibration 1820, the base station 1821 and / or the terminal 1823 may have a configuration of the calibration device 200 illustrated in FIG. 2B, and phase arrangement using at least one of the communication unit 250, the storage unit 260, the control unit 270, and the feedback loop 280. The antenna can be calibrated.

According to various embodiments of the present disclosure, resources for the online calibration 1820 (hereinafter, referred to as “calibration resources”) may be defined. For example, the calibration resource may include a time slot. The communication devices may transmit or receive a signal (eg, a combination signal, a reference signal, and / or a test signal) for acquiring a measurement value using a calibration resource for the online calibration 1820. The calibration resource may be pre-configured, set by higher layer signaling, or dynamically allocated by physical layer signaling (eg, downlink control information (DCI)).

Self-Calibration The 1830 calibrates the calibration when the calibration device self-calibrates the phased array antenna included in the calibration device without the help of another device (e.g. without the help of an external instrument or sending / receiving signals to or from another device). it means. In this case, the calibration device may acquire the measured value by itself and calibrate its phased array antenna based on the measured value. According to various embodiments of the present disclosure, a calibration device that performs self calibration 1830 may be a communication device such as a base station or a terminal. For self calibration 1830, the calibration device may include at least one of an internal instrument 1831 and a beamforming calibration network 1833. The internal instrument 1831 generates a control signal for the measurement, obtains a measurement value by measuring the intensity of the signals (e.g., combination signal, test signal and / or reference signal), and calculates a calibration code based on the measurement value. You can decide. For example, the internal meter 1831 may be part of the controller 270. The beamforming calibration network 1833 may include circuitry (eg, a feedback loop 280) to transmit and process signals for measurement. For self-calibration 1830, the calibration device may have a configuration of the calibration device 200 shown in FIG. 2B, and may calibrate the phased array antenna using at least one of the communication unit 250, the storage unit 260, the control unit 270, and the feedback loop 280. have.

19A and 19B illustrate signal exchange between communication devices for online calibration according to various embodiments of the present disclosure.

Referring to FIG. 19A, the base station 1910 transmits signals (eg, a combination signal, a reference signal, and / or a test signal) to the terminal 1920 through a wireless access channel, and transmits the signals measured by the terminal 1920. Information about the strength may be received from the terminal 1920. The base station 1910 may determine a calibration code of a target RF chain for transmission based on the measured strengths of the signals, and may calibrate the phased array antenna of the base station 1910. In addition, the base station 1910 may receive a calibration signal from the terminal 1920 through a wireless access channel, and measure the strength of the combined signal, the reference signal, and / or the test signal based on the calibration signal. The base station 1910 may determine a calibration code of the target RF chain based on the measured strengths of the signals, determine a calibration code of the target RF chain for reception, and calibrate the phased array antenna of the base station 1910.

The terminal 1920 may transmit signals (eg, a combination signal, a reference signal, and / or a test signal) to the base station 1910 through a wireless access channel, and receive information about the strength of the signals measured by the base station 1910 from the base station 1910. have. The terminal 1920 may determine a calibration code of the target RF chain for transmission based on the measured strengths of the signals, and may calibrate the phased array antenna of the terminal 1920. In addition, the terminal 1920 may receive a calibration signal from the base station 1910 through a wireless access channel, and measure the strength of the combined signal, the reference signal, and / or the test signal based on the calibration signal. The terminal 1920 may determine a calibration code of the target RF chain for reception based on the measured strengths of the signals, and may calibrate the phased array antenna of the terminal 1920.

Referring to FIG. 19B, the base station 1930 transmits signals (eg, a combination signal, a reference signal, and / or a test signal) to the base station 1940 through a wireless backhaul channel, and transmits the signals measured by the base station 1940. Information about the strength may be received from the base station 1940. The base station 1930 may determine a calibration code of the target RF chain for transmission based on the measured strengths of the signals, and may calibrate the phased array antenna of the base station 1930. In addition, the base station 1930 may receive a calibration signal from the base station 1940 through a wireless access channel, and measure the strength of the combined signal, the reference signal, and / or the test signal based on the calibration signal. The base station 1930 may determine a calibration code of the target RF chain for reception based on the measured strengths of the signals, and may calibrate the phased array antenna of the base station 1930.

In the examples of FIGS. 19A and 19B, a signal transmitted or received via a radio access channel or a wireless backhaul channel may be transmitted or received using a calibration resource.

20 is a flowchart illustrating on-line calibration according to various embodiments of the present disclosure. 20 illustrates the operation of the calibration device 200.

Referring to FIG. 20, in step 2001, the calibration apparatus sets each of the phase codes in a target RF chain, and transmits a combination signal for each phase code to another communication device. The combined signal may be transmitted over a radio access channel and / or a wireless backhaul channel, and may be transmitted using a calibration resource. The calibration device may transmit a reference signal and / or a test signal to another communication device in addition to the combination signal.

In step 2003, the calibration device receives information about the strength of the combined signal measured by the other device from the other communication device. The calibration device may receive information about the strength of another signal (eg, a reference signal and / or a test signal) from another communication device in addition to the information about the strength of the combined signal.

In step 2005, the calibration device estimates at least one candidate code for the calibration code of the target RF chain based on the strength of the combined signal. In other words, the calibration device may acquire measurement values for calibrating the phased array antenna by communicating with another communication device.

Once the phased array antenna is calibrated, the phased array antenna can emit electromagnetic waves or form beams in the desired direction. Hereinafter, operations for forming a beam in a specific direction after calibration will be described with reference to FIG. 21.

21 illustrates a flowchart for forming a beam in a specific direction after calibration according to various embodiments of the present disclosure. 21 illustrates the operation of calibration device 200. In this example, the calibration device 200 may be a communication device such as a base station and / or a terminal.

Referring to FIG. 21, in operation 2101, the calibration apparatus determines a direction of a beam for transmitting and receiving a signal. For example, the calibration device may determine the direction of the transmission beam and / or the direction of the reception beam through beam training or beam sweeping with another communication device.

In operation 2103, the calibration apparatus determines a phase code of the RF chain corresponding to the determined direction. According to various embodiments of the present disclosure, when a calibration code is set in all RF chains of a phased array antenna, signals related to the RF chains may all have the same phase and propagate in a specific direction as a whole. When a calibration code is set in all the RF chains of the phased array antenna, the propagation direction of signals related to the RF chains may be referred to as a 'reference direction'. The calibration apparatus may determine the angle difference between the direction of the desired signal and the reference direction, and determine the amount of phase change and the code difference required for each RF chain for the determined angle difference. Here, the amount of phase change and the code difference required for each RF chain may be different for each RF chain. The calibration apparatus may determine the phase code to be set for each RF chain in order to form a beam in a desired direction by applying the code difference determined for the calibration code of each RF chain. In other words, the calibration device may determine a phase code for each RF chain such that the code difference (or phase change amount corresponding to the code difference and / or phase difference) between the phase code and the calibration code corresponds to the desired direction.

In operation 2105, the calibration apparatus sets the determined phase code in the RF chain, and transmits and receives a signal through the beam in the determined direction. RF chains in which a phase code corresponding to the determined direction is set may form a plane wave as a whole, and signals related to the RF chains may be propagated in a desired direction as a whole.

Methods according to the embodiments described in the claims or the specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

When implemented in software, a computer-readable storage medium for storing one or more programs (software modules) may be provided. One or more programs stored in a computer readable storage medium are configured for execution by one or more processors in an electronic device. One or more programs include instructions that cause an electronic device to execute methods in accordance with embodiments described in the claims or specifications of this disclosure.

Such programs (software modules, software) may include random access memory, non-volatile memory including flash memory, read only memory (ROM), and electrically erasable programmable ROM. (electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc-ROM (CD-ROM), digital versatile discs (DVDs) or other forms It can be stored in an optical storage device, a magnetic cassette. Or, it may be stored in a memory composed of some or all of these combinations. In addition, each configuration memory may be included in plural.

In addition, the program may be configured through a communication network composed of a communication network such as the Internet, an intranet, a local area network, a wide area network, or a storage area network, or a combination thereof. It may be stored in an attachable storage device that is accessible. Such a storage device may be connected to a device that performs an embodiment of the present disclosure through an external port. In addition, a separate storage device on a communication network may be connected to a device that performs an embodiment of the present disclosure.

In specific embodiments of the present disclosure described above, components included in the disclosure are expressed in the singular or plural number according to the specific embodiments presented. However, the singular or plural expressions are selected to suit the circumstances presented for convenience of description, and the present disclosure is not limited to the singular or plural elements, and the singular or plural elements may be used in the singular or the singular. Even expressed components may be composed of a plurality.

Meanwhile, in the detailed description of the present disclosure, specific embodiments have been described, but various modifications may be possible without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be determined not only by the scope of the following claims, but also by the equivalents of the claims.

Claims (20)

A method for calibrating a phased array antenna, the method comprising:
Estimating at least one candidate code for a calibration code of the target RF chain by setting phase codes on a target radio frequency (RF) chain;
The strength of the first combined signal estimated for the phase codes and the three-time error of the second combined signal measured for the phase codes under the condition that the at least one candidate code corresponds to a reference phase The decision making process,
Determining the calibration code based on the error;
Calibrating the target RF chain by setting the calibration code to the target RF chain,
Wherein the first combined signal and the second combined signal comprise a combination of signals associated with the target RF chain and the reference RF chain.
The method of claim 1, wherein the phase codes include a first phase code, a second phase code, and a second phase code, wherein the at least one candidate code comprises a first candidate code and a second candidate code,
Estimating the at least one candidate code,
Determine a first phase difference between a phase corresponding to the first phase code and a reference phase based on the strength of the combined signal measured for the first phase code, and measure the strength of the combined signal measured for the second phase code Determining a second phase difference between a phase corresponding to the second phase code and the reference phase based on
Determine a phase state of the first phase difference based on the strength of the combined signal measured for the second phase code, and determine the phase state of the second phase difference based on the strength of the combined signal measured for the third phase code Determining the phase state,
Estimate the first candidate code based on the first phase difference and the phase state of the first phase difference, and estimate the second candidate code based on the second phase difference and the phase state of the second phase difference. How to include.
The phase difference between the phase corresponding to the first phase code and the phase corresponding to the second phase code is 90 °.
And the phase difference between the phase corresponding to the second phase code and the phase corresponding to the third phase code is 90 degrees.
The method of claim 2, wherein the determining of the error comprises
Determining an intensity of the combined signal estimated for the phase codes and a three-time first error of the second combined signal under the condition that the first candidate code corresponds to the reference phase;
Determining a strength of the combined signal estimated for the phase codes and a three-time second error of the second combined signal under the condition that the second candidate code corresponds to the reference phase;
The process of determining the calibration code,
Determining the first candidate code as the calibration code when the first error is smaller than the second error;
If the second error is smaller than the first error, determining the second candidate code as the calibration code.
The method of claim 2, wherein the first candidate for the strength of the signal associated with the target RF chain is based on the strength of the combined signal measured for the first phase code and the strength of the combined signal measured for the third phase code. Estimating the value,
Estimating a second candidate value for the strength of the signal associated with the target RF chain based on the strength of the combined signal measured for the first phase code and the strength of the combined signal measured for the second phase code and,
The difference between the first candidate value and the second candidate value is equal to or less than a third threshold value, and the difference between three periods of at least one of the first candidate value and the second candidate value and the signal associated with the reference RF chain is a fourth threshold value. Further comprising the step of determining whether a condition below the value is satisfied,
Estimating the first candidate code and the second candidate code includes estimating the first candidate code and the second candidate code when the condition is satisfied.
The method of claim 2, further comprising: determining whether a code difference between the first candidate code and the second candidate code is equal to or less than a fifth threshold value, and
The determining of the calibration code may include determining one of the first candidate code and the second candidate code as a calibration code when the code difference is less than or equal to the fifth threshold.
The method of claim 1, further comprising: measuring a strength of a signal associated with the reference RF chain;
Determining whether the measured signal strength is between a first threshold value and a second threshold value;
And measuring the strength of the second combined signal based on a signal associated with the reference RF chain when the strength of the measured signal is between the first threshold and the second threshold.
The method of claim 1, further comprising: determining an additional candidate code within a threshold code difference from the at least one candidate code;
Determining the strength of the combined signal estimated for the phase codes and the three period error of the second combined signal when the additional candidate code is set in the reference RF chain,
The determining of the calibration code comprises: determining the calibration code based on the determined errors.
The method of claim 1, further comprising: transmitting the second combined signal to another communication device;
Receiving information about the strength of the second combined signal measured by the other communication device from the other communication device,
Wherein the at least one candidate code is estimated based on information about the strength of the received second combined signal.
The method of claim 1, further comprising: determining a direction of a beam for transmitting and receiving a signal;
Determining the phase code of the target RF chain such that a code difference between a phase code and the calibration code corresponds to the determined direction;
Setting the phase code to the target RF chain, and transmitting and receiving the signal through the beam in the direction.
An apparatus for calibrating a phased array antenna, the apparatus comprising:
Setting phase codes on a target radio frequency (RF) chain to estimate at least one candidate code for a calibration code of the target RF chain,
The strength of the first combined signal estimated for the phase codes and the three-time error of the second combined signal measured for the phase codes under the condition that the at least one candidate code corresponds to a reference phase Decide,
Based on the error, determine the calibration code,
And a controller configured to set the calibration code to the target RF chain and to calibrate the target RF chain.
Wherein the first combined signal and the second combined signal comprise a combination of signals associated with the target RF chain and the reference RF chain.
The method of claim 11, wherein the phase codes include a first phase code, a second phase code, and a second phase code, wherein the at least one candidate code comprises a first candidate code and a second candidate code,
The control unit,
Determine a first phase difference between a phase corresponding to the first phase code and a reference phase based on the strength of the combined signal measured for the first phase code, and measure the strength of the combined signal measured for the second phase code Determine a second phase difference between a phase corresponding to the second phase code and the reference phase based on
Determine a phase state of the first phase difference based on the strength of the combined signal measured for the second phase code, and determine the phase state of the second phase difference based on the strength of the combined signal measured for the third phase code Determine the phase state,
Estimate the first candidate code based on the first phase difference and the phase state of the first phase difference, and estimate the second candidate code based on the second phase difference and the phase state of the second phase difference. Device.
The phase difference between the phase corresponding to the first phase code and the phase corresponding to the second phase code is 90 °.
And the phase difference between the phase corresponding to the second phase code and the phase corresponding to the third phase code is 90 degrees.
The method of claim 12, wherein the control unit,
Determine an intensity of the combined signal estimated for the phase codes and a three-time first error of the second combined signal under the condition that the first candidate code corresponds to the reference phase,
Determine an intensity of the combined signal estimated for the phase codes and a three-time second error of the second combined signal under the condition that the second candidate code corresponds to the reference phase,
If the first error is smaller than the second error, determine the first candidate code as the calibration code,
And determine the second candidate code as the calibration code if the second error is smaller than the first error.
The method of claim 12, wherein the control unit,
Estimate a first candidate value for the strength of the signal associated with the target RF chain based on the strength of the combined signal measured for the first phase code and the strength of the combined signal measured for the third phase code,
Estimate a second candidate value for the strength of the signal associated with the target RF chain based on the strength of the combined signal measured for the first phase code and the strength of the combined signal measured for the second phase code,
The difference between the first candidate value and the second candidate value is equal to or less than a third threshold value, and the difference between three periods of at least one of the first candidate value and the second candidate value and the signal associated with the reference RF chain is a fourth threshold value. Determine whether the condition is less than or equal to
And if the condition is met, estimating the first candidate code and the second candidate code.
The method of claim 12, wherein the controller is further configured to determine whether a code difference between the first candidate code and the second candidate code is equal to or less than a fifth threshold value.
And determine one of the first candidate code and the second candidate code as a calibration code when the code difference is less than or equal to the fifth threshold.
The method of claim 11, wherein the control unit,
Measure the strength of the signal associated with the reference RF chain,
Determine whether the measured signal strength is between a first threshold value and a second threshold value,
And measure the strength of the second combined signal based on a signal associated with the reference RF chain when the strength of the measured signal is between the first threshold and the second threshold.
The method of claim 11, wherein the control unit,
Determine an additional candidate code within a threshold code difference from the at least one candidate code,
Determining the strength of the combined signal estimated for the phase codes and the three period error of the second combined signal when the additional candidate code is set in the reference RF chain,
And determine the calibration code based on the determined errors.
The apparatus of claim 11, further comprising: a communication unit configured to transmit the second combined signal to another communication device, and to receive information about the strength of the second combined signal measured by the other communication device from the other communication device,
And the at least one candidate code is estimated based on information about the strength of the received second combined signal.
The apparatus of claim 11, wherein the controller determines a direction of a beam for transmitting and receiving a signal, and determines the phase code of the target RF chain such that a code difference between a phase code and the calibration code corresponds to the determined direction,
And a communication unit configured to set the phase code to the target RF chain and transmit and receive the signal through the beam in the direction.

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