KR20130062764A

KR20130062764A - System and method for testing mimo ota performance of mobile terminal

Info

Publication number: KR20130062764A
Application number: KR1020110129193A
Authority: KR
Inventors: 김영렬; 심혜정; 조용상; 노승표
Original assignee: 엘지전자 주식회사
Priority date: 2011-12-05
Filing date: 2011-12-05
Publication date: 2013-06-13

Abstract

PURPOSE: An MIMO(Multiple Input Multiple Output) OTA(Over The Air) performance measurement system of a portable terminal and a method thereof are provided to rapidly measure the performance of an MIMO device such as the portable terminal. CONSTITUTION: An emulator(50) generates a test signal. A fading channel emulator(51) converts the test signal into a multiple channel signal. A chamber(52) receives the transmitted multiple channel signal from a portable terminal which is a testing device. The chamber measures the maximum throughput of the test signal according to MCS change based on the emulator. The MCS of the test signal is over a predetermined value. [Reference numerals] (AA) Vertically polarized wave; (BB) Horizontally polarized wave

Description

MIM OOTA performance measurement system of mobile terminal and method therefor {SYSTEM AND METHOD FOR TESTING MIMO OTA PERFORMANCE OF MOBILE TERMINAL}

The present invention relates to a MIMO OTA performance measurement system and method for measuring the performance of a MIMO device such as a mobile terminal.

In general, the LTE system is an evolution from the UMTS system and is largely divided into a wireless network (E-UTRAN) and a core network (CN). The wireless network includes a user equipment (UE), a base station (hereinafter abbreviated to eNode B), and an access gateway (AG) located at an end of a network and connected to an external network.

One or more cells may exist in one base station (eNode B) in the wireless network. An interface for transmitting user traffic or control traffic is used between the eNode Bs. The core network (CN) is composed of a node for user registration of the access gate (AG) and other mobile terminals.

In the LTE system, two axes constituting a wireless network are a base station and a terminal. The radio resource in one cell is composed of an uplink radio resource and a downlink radio resource.

The base station allocates and controls uplink radio resources and downlink radio resources of the cell. That is, the base station determines which radio resource is used by which terminal at any moment. The base station notifies the terminal of the determined result so that the terminal receives the downlink data or transmits the data upward.

MIMO (Multiple Input Multiple Output) technology, unlike SISO (Single Input Single Output) technology, which uses one transmit / receive antenna one by one, uses two or more transmit / receive antennas to improve call quality and transmit a lot of data. The antenna using the SISO technology increases transmission efficiency of data through the antenna by using transmit diversity (Tx transmit diversity), and the antenna using the MIMO technology uses open loop spatial multiplexing technology. Increase the transmission efficiency.

The performance of the terminal in the LTE-based wireless communication system is greatly affected by the antenna characteristics and the radio wave environment. In the case of LTE-based devices, especially mobile terminals, to which the MIMO technology is applied, a MIMO OTA (Over The Air) test is essential to accurately compare antenna performance.

Accordingly, there is a need for various MIMO OTA tests to measure the performance of MIMO devices more quickly and conveniently in an LTE-based wireless communication system.

An object of the present invention is to provide a MIMO OTA performance measurement system and method that can measure the performance of a MIMO device such as a mobile terminal more quickly and conveniently.

In order to achieve the above object, a method for measuring MIMO OTA performance of a mobile terminal according to an embodiment of the present invention includes fixing a transmission power of a test signal; Adjusting a transmission rate of the test signal by changing a modulation and coding selection (MCS) of the test signal; Converting the adjusted test signal into a multi-channel signal and transmitting the multi-channel signal; And measuring the maximum throughput according to the MCS change by receiving the transmitted multi-channel signal at the mobile terminal of the chamber.

MCS of the test signal is applied only to the MCS of a predetermined value or more through the preprocessing step.

The transmission power of the test signal is fixed at a high transmission power, and the maximum throughput is displayed on a monitor connected to the mobile terminal.

Adjusting the transmission power of the test signal to a predetermined step further comprising the step of expressing the throughput value in dB scale.

And measuring a target block error rate (BLER) of the mobile terminal by changing a transmission power while the MCS of the test signal is fixed.

In order to achieve the above object, MIMO OTA performance measurement system of a mobile terminal according to an embodiment of the present invention includes an emulator for generating a test signal; A fading channel emulator converting the test signal into a multi-channel signal; And a chamber configured to receive the transmitted multi-channel signal at a mobile terminal, which is a test device, and measure a maximum throughput of the test signal according to the MCS change by the emulator.

And a monitor for displaying the measured throughput, wherein the transmit power of the test signal is fixed to a high transmit power by an emulator.

The emulator adjusts the transmission power of the test signal in a predetermined step so that the measured throughput value is expressed in dB scale.

The emulator changes the transmission power while the MCS of the test signal is fixed so that the target block error rate (BLER) of the mobile terminal can be measured.

The present invention can measure the performance of the device to which the MIMO technology is applied using the MIMO OTA performance measurement system to quickly and accurately measure the MIMO performance of the device in the future Lab.

1 is a block diagram of a mobile terminal according to an embodiment of the present invention;
2 is a block diagram of a wireless communication system in which a mobile terminal may operate in accordance with an embodiment of the present invention.
3 is a block diagram of a MIMO OTA performance measurement system according to an embodiment of the present invention.
4A and 4B illustrate a first embodiment of a method for measuring MIMO OTA performance of a mobile terminal according to an embodiment of the present invention.
5A and 5B illustrate a first embodiment of a method for measuring MIMO OTA performance of a mobile terminal according to an embodiment of the present invention.
6 is a flow chart of a method for measuring MIMO OTA performance according to an embodiment of the present invention.

Hereinafter, a mobile terminal related to the present invention will be described in detail with reference to the drawings. The suffix "module" and " part "for components used in the following description are given merely for convenience of description, and do not give special significance or role in themselves. Therefore, it should be noted that the "module" and "unit" may be used interchangeably with each other.

The terminal may be implemented in various forms. For example, a terminal described herein includes a mobile terminal such as a mobile phone, a smart phone, a notebook computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation device, and the like. And fixed terminals such as digital TVs, desktop computers, and the like. In the following description, it is assumed that the terminal is a mobile terminal. However, it will be readily apparent to those skilled in the art that the configuration according to the following description may be applied to the fixed terminal, except for components specifically configured for mobile use.

1 is a block diagram of a mobile terminal according to an embodiment of the present invention.

The mobile terminal 100 includes a wireless communication unit 110, an audio / video input unit 120, a user input unit 130, a sensing unit 140, an output unit 150, a memory 160, A controller 170, a controller 180, a power supply 190, and the like. 1 shows a mobile terminal having various components. However, not all illustrated components are required. A mobile terminal may be implemented by more components than the illustrated components, or a mobile terminal may be implemented by fewer components.

Hereinafter, the components will be described in order.

The wireless communication unit 110 may include one or more components that allow wireless communication between the mobile terminal 100 and the wireless communication system or wireless communication between the mobile terminal 100 and a network on which the mobile terminal 100 is located. For example, the wireless communication unit 110 may include a broadcast receiving module 111, a mobile communication module 112, a wireless Internet module 113, a short range communication module 114, and a location information module 115 .

The broadcast receiving module 111 receives a broadcast signal and / or broadcast related information from an external broadcast management server through a broadcast channel. The broadcast channel may include a satellite channel and a terrestrial channel. The broadcast management server may refer to a server for generating and transmitting broadcast signals and / or broadcast related information, or a server for receiving broadcast signals and / or broadcast related information generated by the broadcast management server and transmitting the generated broadcast signals and / or broadcast related information. The broadcast-related information may refer to a broadcast channel, a broadcast program, or information related to a broadcast service provider. The broadcast signal may include a TV broadcast signal, a radio broadcast signal, a data broadcast signal, and a broadcast signal in which a data broadcast signal is combined with a TV broadcast signal or a radio broadcast signal.

Meanwhile, the broadcast related information may be provided through a mobile communication network, and in this case, it may be received by the mobile communication module 112.

The broadcast related information may exist in various forms. For example, it may exist in the form of Electronic Program Guide (EPG) of Digital Multimedia Broadcasting (DMB) or Electronic Service Guide (ESG) of Digital Video Broadcast-Handheld (DVB-H).

The broadcast receiving module 111 receives broadcasting signals using various broadcasting systems. In particular, the broadcasting receiving module 111 may be a Digital Multimedia Broadcasting-Terrestrial (DMB-T), a Digital Multimedia Broadcasting-Satellite (DMB-S) Only Digital Broadcast-Handheld (DVB-H), Integrated Services Digital Broadcast-Terrestrial (ISDB-T), and the like. Of course, the broadcast receiving module 111 is configured to be suitable for all broadcasting systems that provide broadcasting signals as well as the digital broadcasting system described above.

The broadcast signal and / or broadcast related information received through the broadcast receiving module 111 may be stored in the memory 160.

In addition, the mobile communication module 112 transmits and receives radio signals to at least one of a base station, an external terminal, and a server on a mobile communication network. Here, the wireless signal may include various types of data depending on a voice call signal, a video call signal, or a text / multimedia message transmission / reception.

The wireless Internet module 113 is a module for wireless Internet access, and the wireless Internet module 113 can be built in or externally. WLAN (Wi-Fi), Wibro (Wireless broadband), Wimax (World Interoperability for Microwave Access), HSDPA (High Speed Downlink Packet Access) and the like can be used as wireless Internet technologies.

The short range communication module 114 refers to a module for short range communication. Bluetooth, radio frequency identification (RFID), infrared data association (IrDA), ultra wideband (UWB), ZigBee, and the like can be used as the short distance communication technology.

The location information module 115 is a module for confirming or obtaining the location of the mobile terminal. A typical example of the position information module 115 is a Global Position System (GPS) module. According to the current technology, the GPS module calculates distance information and accurate time information from three or more satellites, and then applies trigonometry to the calculated information to obtain three-dimensional current position information according to latitude, longitude, and altitude It can be calculated accurately. At present, a method of calculating position and time information using three satellites and correcting an error of the calculated position and time information using another satellite is widely used. In addition, the GPS module can calculate speed information by continuously calculating the current position in real time.

An audio / video (A / V) input unit 120 is for inputting an audio signal or a video signal, and may include a camera 121 and a microphone 122. The camera 121 processes an image frame such as a still image or a moving image obtained by the image sensor in the video communication mode or the photographing mode. Then, the processed image frame can be displayed on the display module 151.

The image frame processed by the camera 121 may be stored in the memory 160 or transmitted to the outside through the wireless communication unit 110. [ The camera 121 may be equipped with two or more cameras according to the configuration of the terminal.

The microphone 122 receives an external sound signal through a microphone in a communication mode, a recording mode, a voice recognition mode, or the like, and processes it as electrical voice data. The processed voice data can be converted into a form that can be transmitted to the mobile communication base station through the mobile communication module 112 when the voice data is in the call mode, and output. The microphone 122 may be implemented with various noise reduction algorithms for eliminating noise generated in the process of receiving an external sound signal.

The user input unit 130 generates input data for a user to control the operation of the terminal. The user input unit 130 may include a key pad, a dome switch, a touch pad (static / static), a jog wheel, a jog switch, and the like. Particularly, when the touch pad has a mutual layer structure with the display module 151 described later, it can be called a touch screen.

The sensing unit 140 senses the current state of the mobile terminal 100 such as the open / close state of the mobile terminal 100, the position of the mobile terminal 100, the presence or absence of user contact, the orientation of the mobile terminal, And generates a sensing signal for controlling the operation of the mobile terminal 100. For example, when the mobile terminal 100 is in the form of a slide phone, it may sense whether the slide phone is opened or closed. Also, it is responsible for a sensing function related to whether or not the power supply unit 190 is powered on, whether the interface unit 170 is connected to an external device, and the like. Meanwhile, the sensing unit 140 may include a proximity sensor 141. This will be discussed later in connection with touch screens.

The sensing unit 140 includes a geomagnetic sensor for calculating a moving direction when a user moves, a gyro sensor for calculating a rotating direction, and an acceleration sensor.

The interface unit 170 serves as an interface with all external devices connected to the mobile terminal 100. For example, a wired / wireless headset port, an external charger port, a wired / wireless data port, a memory card port, a port for connecting a device having an identification module, an audio I / O port, Video input / output (I / O) ports, earphone ports, and the like.

Here, the identification module is a chip that stores various information for authenticating the use right of the mobile terminal 100, and includes a user identification module (UIM), a subscriber identity module (SIM) ), A Universal Subscriber Identity Module (" USIM "), and the like. In addition, an apparatus having an identification module (hereinafter referred to as 'identification device') can be manufactured in a smart card format. Accordingly, the identification device can be connected to the terminal 100 through the port. The interface unit 170 receives data from an external device or receives power from the external device to transfer the data to each component in the mobile terminal 100 or to transmit data in the mobile terminal 100 to an external device.

The interface unit 170 may be a path through which power from the cradle is supplied to the mobile terminal 100 when the mobile terminal 100 is connected to an external cradle, Various command signals may be transmitted to the mobile terminal. The various command signals or the power source input from the cradle may be operated as a signal for recognizing that the mobile terminal is correctly mounted on the cradle.

The output unit 150 is for outputting an audio signal, a video signal, or an alarm signal. The output unit 150 may include a display module 151, an audio output module 152, and an alarm unit 153.

The display module 151 displays and outputs information processed by the mobile terminal 100. For example, when the mobile terminal is in the call mode, a UI (User Interface) or a GUI (Graphic User Interface) associated with a call is displayed.

Meanwhile, as described above, when the display module 151 and the touch pad have a mutual layer structure to constitute a touch screen, the display module 151 can be used as an input device in addition to the output device. The display module 151 may be a liquid crystal display, a thin film transistor-liquid crystal display, an organic light-emitting diode, a flexible display, a three-dimensional display 3D display). Some of these displays can be configured to be transparent so that they can be viewed from outside. This may be referred to as a transparent display. A typical example of the transparent display is a transparent organic light emitting diode (TOLED) or the like. In addition, there may be two or more display modules 151 according to the embodiment of the mobile terminal 100. For example, the mobile terminal 100 may be provided with an external display module (not shown) and an internal display module (not shown) at the same time. The touch screen may be configured to detect not only the touch input position and area but also the touch input pressure.

The audio output module 152 outputs audio data received from the wireless communication unit 110 or stored in the memory 160 in a call signal reception mode, a call mode or a recording mode, a voice recognition mode, a broadcast reception mode, The sound output module 152 outputs an acoustic signal related to functions (e.g., call signal reception sound, message reception sound, etc.) performed in the mobile terminal 100. [ The sound output module 152 may include a speaker, a buzzer, and the like.

The alarm unit 153 outputs a signal for notifying the occurrence of an event of the mobile terminal 100. Examples of events that occur in the mobile terminal include call signal reception, message reception, key signal input, touch input, and the like. The alarm unit 153 may output a signal for informing occurrence of an event in a form other than an audio signal or a video signal. For example, it is possible to output a signal in a vibration mode. When a call signal is received or a message is received, the alarm unit 153 can output a vibration to notify it. Alternatively, when the key signal is input, the alarm unit 153 can output the vibration by the feedback to the key signal input. The user can recognize the occurrence of an event through the vibration output as described above. Of course, a signal for notifying the occurrence of an event may also be output through the display module 151 or the sound output module 152.

The memory 160 may store a program for processing and controlling the controller 180 and may provide a function for temporarily storing input / output data (for example, a phone book, a message, a still image, a video, etc.). It can also be done. In addition, the memory 160 may store data on vibration and sound of various patterns output when a touch input on the touch screen is performed.

The memory 160 may be a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (for example, SD or XD memory), a RAM (Random Access Memory) SRAM (Static Random Access Memory), ROM (Read Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), PROM (Programmable Read- And an optical disc. Also, the mobile terminal 100 may operate a web storage for performing a storage function of the memory 160 on the Internet.

The control unit 180 typically controls the overall operation of the mobile terminal. For example, voice communication, data communication, video communication, and the like. In addition, the control unit 180 may include a multimedia module 181 for multimedia playback. The multimedia module 181 may be implemented in the control unit 180 or may be implemented separately from the control unit 180. [

The controller 180 may perform a pattern recognition process for recognizing handwriting input or drawing input performed on the touch screen as characters and images, respectively.

The power supply unit 190 receives external power and internal power under the control of the control unit 180 as a battery, and supplies power necessary for operation of the respective components.

The various embodiments described herein may be embodied in a recording medium readable by a computer or similar device using, for example, software, hardware, or a combination thereof.

According to a hardware implementation, the embodiments described herein may be implemented as application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays May be implemented using at least one of processors, controllers, micro-controllers, microprocessors, and electrical units for performing functions. In some cases, And may be implemented by the control unit 180.

According to a software implementation, embodiments such as procedures or functions may be implemented with separate software modules that perform at least one function or operation. The software code may be implemented by a software application written in a suitable programming language. In addition, the software codes may be stored in the memory 160 and executed by the control unit 180. [

The terminal 100 shown in Fig. 1 is configured to be operable in a communication system capable of transmitting data through a frame or packet, including a wired / wireless communication system and a satellite-based communication system .

Hereinafter, a communication system capable of operating a terminal according to the present invention will be described with reference to FIG.

The communication system may use different air interfaces and / or physical layers. For example, wireless interfaces that can be used by communication systems include, but are not limited to, Frequency Division Multiple Access ('FDMA'), Time Division Multiple Access ('TDMA'), Code Division Multiple Access (CDMA), Universal Mobile Telecommunications Systems (UMTS) (especially Long Term Evolution (LTE)), Global System for Mobile Communications (GSM) . Hereinafter, for convenience of description, the description will be limited to CDMA. However, the present invention is applicable to all communication systems including CDMA wireless communication systems.

2, the CDMA wireless communication system includes a plurality of terminals 100, a plurality of base stations (BSs) 270, and base station controllers (BSCs) 275 , And a mobile switching center ('MSC') 280. The MSC 280 is configured to be connected to a public switched telephone network (PSTN) 290 and is also configured to be connected to BSCs 275. BSCs 275 may be coupled in pairs with BS 270 through a backhaul line. The backhaul line may be provided according to at least one of E1 / T1, ATM, IP, PPP, Frame Relay, HDSL, ADSL, or xDSL. Thus, a plurality of BSCs 275 may be included in the system shown in FIG.

Each BS 270 may comprise at least one sector, and each sector may comprise an omnidirectional antenna or an antenna pointing to a particular direction of radial from BS 270. [ In addition, each sector may include two or more antennas of various types. Each BS 270 may be configured to support a plurality of frequency assignments, each of which has a specific spectrum (eg, 1.25 MHz, 5 MHz, etc.).

The intersection of sectors and frequency assignments may be called a CDMA channel. BS 270 may be referred to as a Base Station Transceiver Subsystem (BTSs). In this case, the word "base station" may be referred to as a combination of one BSC 275 and at least one BS 270. [ The base station may also indicate “cell site”. Alternatively, each of the plurality of sectors for a particular BS 270 may be referred to as a plurality of cell sites.

2, a broadcasting transmitter (BT) 295 transmits a broadcasting signal to the terminals 100 operating in the system. The broadcast receiving module 111 shown in FIG. 1 is provided in the terminal 100 to receive a broadcast signal transmitted by the BT 295.

In addition, FIG. 2 illustrates several Global Positioning System ('GPS') satellites 300. The satellites 300 help to locate at least one of the plurality of terminals 100. Although two satellites are shown in FIG. 2, useful location information may be obtained by two or more satellites. The location information module 115 shown in FIG. 1 cooperates with satellites 300 to obtain desired location information. Here, the location can be tracked using all the techniques that can track the location, not just the GPS tracking technology. Also, at least one of the GPS satellites 300 may optionally or additionally be responsible for satellite DMB transmission.

Among the typical operations of a wireless communication system, the BS 270 receives a reverse link signal from the various terminals 100. At this time, the terminals 100 are connecting a call, transmitting or receiving a message, or performing another communication operation. Each of the reverse link signals received by the particular base station 270 is processed by the particular base station 270. The data resulting from the processing is transmitted to the connected BSC 275. The BSC 275 provides call resource allocation and mobility management functions, including the organization of soft handoffs between the base stations 270. The BSC 275 also transmits the received data to the MSC 280 and the MSC 280 provides additional transmission services for connection with the PSTN 290. [ Similarly, the PSTN 290 connects to the MSC 280, the MSC 280 connects to the BSCs 275, and the BSCs 275 communicate with the BSs 270 ).

In general, MIMO increases the number of antennas in a system and each MIMO antenna is arranged not to be connected to each other. However, in the case of LTE-based devices (e.g., mobile terminals) with MIMO technology, designing and measuring the performance of the multiband MIMO antenna without interaction in a narrow space determines the overall system performance. Therefore, MIMO OTA measurement is used as one method for predicting the actual radiation performance of the latest MIMO terminal.

The MIMO OTA test transmits a MIMO signal to a terminal while changing a power power or modulation and coding scheme (MCS) at a lab, that is, based on a report of the terminal about the MIMO signal. This means testing the MIMO performance of the terminal.

The present invention can arbitrarily create a wireless channel environment to facilitate the MIMO OTA performance test between the base station system and the mobile station (eg, terminal) in an environment similar to the actual wireless environment, and variably adjusts the path attenuation rate of the wireless channel. Can be applied in MIMO OTA performance measurement system.

3 is a block diagram of a MIMO OTA performance measurement system according to an embodiment of the present invention.

As shown in FIG. 3, the MIMO OTA performance measurement system applied to the present invention includes an emulator 50 (base station emulator) that generates a test signal according to a predetermined application, and a test signal generated by the emulator 10. A fading channel emulator 51 for generating a multi-path signal, that is, a multi-channel signal suitable for the MIMO antenna of the receiver, and a multi-channel signal output from the fading channel emulator 51 are received. And a chamber 52 for measuring MIMO antenna performance.

The mobile terminal 100 may be connected to a monitor 53 to display the measured MIMO antenna performance, and the fading channel emulator 51 may convert a multi-channel signal into vertical polarization and horizontal polarization. To create and send.

The chamber 52 is a laboratory for measuring the performance of the MIMO antenna of the test device, and includes a plurality of antennas for receiving the multi-channel signal output from the fading channel emulator 51 and transmitting the multi-channel signal to the measurement device.

In particular, the emulator 50 and the fading channel emulator 51 correspond to the base station side in the actual wireless environment, and the chamber 52 corresponds to the terminal side.

A method of measuring the MIMO OTA performance of the mobile terminal in the MIMO OTA performance measurement system configured as described above is as follows.

In mobile communication, a link adaptation technique is used for efficient use of a radio link. Representative link adaptation techniques include power control techniques and adaptive modulation and coding (AMC) techniques. The power control technique maintains transmission quality by controlling power according to a radio link, and is used in a system for adjusting link quality at a fixed transmission rate such as voice, and the AMC technique is a technique for adjusting a transmission rate to a channel environment. It is also used for multimedia data services requiring various data rates and transmission quality.

Since the AMC determines and transmits an appropriate transmission rate according to the characteristics of the channel, transmission power is basically fixed. The rate is determined by the Modulation and Coding Selection (MCS) level, which represents a level for a predefined modulation and channel coding combination.

In general, in a real wireless environment, a terminal transmits channel quality indicator (CQI or Rank Indicator: RI) of the terminal to the base station, and the base station uses the reception quality information transmitted from the terminal to provide an optimal MIMO performance of the mobile terminal. Control to ensure that However, measuring the MIMO performance of the device in the actual wireless environment as described above takes a lot of time and cost, so the performance measurement through the laboratory is made.

The present invention uses a maximum throughput measurement method to measure MIMO OTA performance. The maximum throughput measurement method is a measurement method that is most similar to a wireless environment of a real field, so that performance of a device can be compared.

The maximum throughput measurement method is a method of searching for the maximum throughput while fixing the transmission power and changing the MCS.

4A and 4B illustrate a first embodiment of a method for measuring MIMO OTA performance of a mobile terminal according to an embodiment of the present invention.

As shown in FIG. 4A, the transmit power of the test signal transmitted through the emulator 50 and the fading channel emulator 51 is fixed at a constant level.

That is, the user transmits the test signal using the emulator 50 while changing the MCS level without changing the transmission power according to the channel environment change. The test signal is transmitted as a multi-channel signal through a fading channel emulator 51. The multi-channel signal output from the fading channel emulator 51 is received by the mobile terminal through a plurality of antennas (not shown) in the chamber 52.

Therefore, the user searches for the maximum throughput while measuring the throughput through the connected monitor 53 to display the MIMO antenna performance of the mobile terminal. In particular, by performing a pre-search step to shorten the search time when changing the MCS, it is possible to shorten the overall MIMO performance test time.

That is, after performing the pre-search step to find the MCS level indicating the throughput below a certain level, the search time can be shortened by excluding the corresponding MCS level in the actual MIMO performance test. In particular, since the signal-to-noise ratio (SNR) is saturated in the high transmission power section, the throughput change according to the correlation of the MCS can be detected more accurately.

In addition, FIG. 4B is an extension concept of the maximum throughput search, and is an example of a graph showing the throughput value measured in FIG. 4A in dB. This method searches for the maximum throughput at a specific transmit power while increasing / decreasing the transmit power.

5A and 5B illustrate a second embodiment of a method for measuring MIMO OTA performance of a mobile terminal according to an embodiment of the present invention.

As shown in FIG. 5A, the second embodiment of the present invention is a method of searching for a target block error rate (BLER), in which transmission power is changed to fix a MCS and find a specific BLER (eg, BLER 30%). This is how you do it. That is, the method is a method for measuring fading sensitivity of the dual antenna.

5B is an extension of the target BLER search, and the MCS can more accurately search for the change in throughput when adjusting the transmission power in a fixed step in a fixed state.

6 is a flowchart illustrating a method for measuring MIMO OTA performance according to an embodiment of the present invention.

As shown in FIG. 6, the user generates a test signal in which the transmission power is fixed to a predetermined level using the emulator 50 (S10).

The generated test signal is converted into a multi-channel signal through a fading channel emulator 51 and then transmitted, and the transmitted multi-channel signal is received by the mobile terminal through a plurality of antennas (not shown) in the chamber 52. .

The user searches for the maximum throughput while measuring the throughput through the monitor 53 connected to the mobile terminal while changing the MCS of the test signal (S11, S12). In particular, by performing a pre-search step to shorten the search time when changing the MCS, it is possible to shorten the overall MIMO performance test time.

Thereafter, the user searches for the maximum throughput while increasing / decreasing the transmission power so that the searched throughput value can be viewed as a dB value (S13).

As described above, the present invention measures the performance of the device to which the MIMO technology is applied by using the MIMO OTA performance measurement system, so that the MIMO performance of the device can be quickly and accurately measured in a future lab.

Further, according to an embodiment of the present invention, the above-described method can be implemented as a code that can be read by a processor on a medium on which the program is recorded. Examples of the medium that can be read by the processor include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage, etc., and may be implemented in the form of a carrier wave (e.g., transmission over the Internet) .

The above-described mobile terminal is not limited to the configuration and method of the above-described embodiments, but the embodiments are configured by selectively combining all or some of the embodiments so that various modifications can be made. May be

Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention, and not all of the technical ideas of the present invention are described. Therefore, It is to be understood that equivalents and modifications are possible.

50: emulator 50 51: fading channel emulator
52: chamber 53: monitor
180: control unit 200: power amplifier
202: transmission power detector 204: antenna matching controller
206: antenna matching unit 150: output unit
151: display unit 160: memory

Claims

Fixing a transmission power of the test signal;
Adjusting a transmission rate of a test signal by changing a modulation and coding selection (MCS) of the test signal;
Converting the adjusted test signal into a multi-channel signal and transmitting the multi-channel signal; And
And measuring the maximum throughput according to MCS change by receiving the transmitted multi-channel signal at the mobile terminal of the chamber.

The method of claim 1, wherein the MCS of the test signal is
MIMO OTA performance measurement method of a mobile terminal, characterized in that only the MCS of a predetermined value or more through the pre-processing step.

The method of claim 1, wherein the transmission power of the test signal is fixed at a high transmission power, and the maximum throughput is displayed on a monitor connected to the mobile terminal.

The method of claim 1, further comprising adjusting the transmit power of the test signal to a predetermined level to represent the measured throughput value in dB scale.

The method of claim 1, further comprising measuring a target block error rate (BLER) of the mobile terminal by varying transmission power while the MCS of the test signal is fixed. .

An emulator for generating a test signal;
A fading channel emulator converting the test signal into a multi-channel signal; And
And a chamber configured to receive the transmitted multi-channel signal at a mobile terminal, which is a test device, and measure a maximum throughput of the test signal according to the MCS change by the emulator.

The method of claim 6, wherein the MCS of the test signal is
MIMO OTA performance measurement system of a mobile terminal, characterized in that only MCS of a predetermined value or more is applied through a preprocessing step.

7. The system of claim 6, further comprising a monitor for displaying the measured throughput, wherein the transmit power of the test signal is fixed at a high transmit power by an emulator.

The method of claim 6, wherein the emulator is
MIMO OTA performance measurement system of a mobile terminal for adjusting the transmission power of the test signal in a predetermined step so that the measured throughput value is expressed in dB scale.

The method of claim 1, wherein the emulator is
MIMO OTA performance measurement system of the mobile terminal to change the transmission power while the MCS of the test signal is fixed to measure the target block error rate (BLER) of the mobile terminal.