JP7219566B2 - Wireless communication test device, wireless communication test method and computer program - Google Patents

Description

The present invention relates to a test device for measuring and measuring the quality of communication between a radio base station and a radio terminal such as a mobile phone or smart phone (and thus the performance of the radio base station or radio terminal). The present invention relates to a wireless communication test apparatus, a wireless communication test method, and a computer program for efficiently measuring the communication quality of wireless terminals and wireless base stations to which the 3GPP (Third Generation Partnership Project) specifications, in which communication control methods have become complicated, including It is.

Currently, in wireless communication systems used in wide areas, 3GPP-specified communication methods such as LTE, which enable effective utilization of frequency resources, are rapidly spreading. In 3GPP, adaptive modulation and coding (AMC) is adopted as an elemental technology for improving communication efficiency. Adaptive modulation and coding is a technology that improves communication efficiency by sequentially selecting the modulation method and coding method used for data transmission and reception according to the radio quality. The effect is exhibited when is easily changed. On the other hand, as an element technology for improving communication quality, retransmission control utilizing HARQ (Hybrid Automatic Repeat reQuest) is incorporated for error correction.

By the way, when conducting evaluation tests of wireless terminals and base stations conforming to the 3GPP specifications, field tests and fading simulators have conventionally been used while the adaptive modulation coding and retransmission control incorporated in the communication protocol are still being performed. Indoor tests have been conducted in a simulated environment. However, in adaptive modulation and coding processing, the modulation method and packet coding rate (MCS: Modulation Coding Scheme) change rapidly according to the communication situation, and the evaluation of the communication quality (throughput, error correction rate, etc.) of the device is particularly important. There is a drawback that it is very difficult to find technical clues for quality improvement while identifying factors of quality deterioration when conducting tests.

Therefore, the 3GPP specifications for communication device evaluation tests recommend that the modulation scheme and coding rate be fixed. For example, FIG. 14 shows a physical downlink control channel measurement reference channel (3GPP specifications: 36.521) in test-driven development (TDD), and FIG. 13 shows a physical uplink control channel measurement reference channel (3GPP specifications: 36 and 141), respectively, and it can be seen that the MCS (modulation scheme and coding rate (coding rate)) are fixedly set in each case.

For example, a pseudo base station tester is used as a device implementing the test mode by the MCS (for example, Patent Document 1). FIG. 14 shows an example of a test system using the pseudo base station tester. The test system 500 shows a connection configuration when evaluating the uplink reception performance of a base station apparatus 501 to be tested. A fading signal generated from a fading simulator (channel simulator) 502 and additive Gaussian white noise (AWGN) generated by a white noise generator 503 are superimposed and input to the reception port of base station apparatus 501 . The base station device 7 receives and detects the test transmission wave, demodulates the received bit data while performing HARQ code correction, and feeds back the code correction result to the base station tester 504 . The base station tester 504 side controls retransmission of packet transmission based on the result of the code correction feedback, and grasps the throughput characteristics during uplink transmission from the time average of the packet transmission amount for which ACK (acknowledgement) is received, for example. can do.

JP 2013-201514 A

However, the method of FIG. 14 has the following drawbacks.
(1) The base station tester 504 uses a dedicated test output channel to set the MCS, and the packet transmission protocol layer also uses the lower layer of 3GGP (for example, the physical layer). Very time consuming. In addition, since packet transmission does not pass through the upper protocol layer, the environment when the communication device is actually used, such as the effects of delays when passing through the upper protocol layer, is accurately reflected in the test results (especially throughput characteristics). It's hard to say.
(2) 3GPP specification wireless communication is performed between a base station apparatus and a wireless terminal, and the combination of the base station apparatus and wireless terminal can also be a factor that affects communication quality. However, in the system of FIG. 14, since the base station equipment is replaced with a dedicated base station tester, there is a drawback that it is not possible to directly test any combination of base station equipment and wireless terminals.

An object of the present invention is to make it possible to set MCS for testing very easily, to realize communication quality measurement in a protocol environment close to the actual use of a communication device, and to make it possible to connect an arbitrary base station device and a wireless terminal. To provide a wireless communication test device capable of simply and directly carrying out a communication test relating to a combination of

A wireless communication test apparatus according to the present invention is a wireless communication tester for measuring the quality of wireless communication implemented according to a communication protocol stack having multiple layers, with one of a wireless base station and a wireless terminal as a transmitting side device and the other as a receiving side device. In order to solve the above problems regarding communication test equipment,
a mode selector that is connected to a transmission-side device and selects either a normal mode that allows execution of adaptive modulation and coding control in a physical layer of a communication protocol stack or a test mode that stops the execution; A modulation and coding information acquisition unit that acquires modulation and coding information including the type and coding rate of the frequency modulation method to be set, and the modulation and coding information that is acquired when the test mode is selected are specified. A modulation coding information setting unit that fixedly sets the frequency modulation method and the coding rate for the physical layer via an upper protocol layer, which is a protocol layer higher than the physical layer, and a test mode are selected. According to the transmission side device, the transmission side device transmits a test packet from the upper protocol layer to the reception side device in a state in which the frequency modulation method and coding rate specified in the modulation and coding information are fixed in the physical layer. a test packet transmission command commanding the
a receiving side test unit connected to the receiving side device and provided with a communication quality measuring section that measures communication quality based on the reception state of the test packet by the receiving side device.

Also, the wireless communication test method of the present invention measures the quality of wireless communication performed according to a communication protocol stack having a plurality of layers, with one of a wireless base station and a wireless terminal as a transmitting side device and the other as a receiving side device. In order to solve the above problems regarding the wireless communication test method of
Selecting a test mode for stopping execution of adaptive modulation and coding control in a physical layer of a communication protocol stack in a test packet transmission command unit connected to a transmitting device; and a frequency modulation scheme to be set in the physical layer. a step of acquiring modulation and coding information including the type and coding rate of the modulation and coding information; a step of fixedly setting the physical layer via a layer; and in a state in which the frequency modulation method and coding rate determined in the modulation coding information are fixedly set in the physical layer, from the upper protocol layer to the receiving side transmitting a test packet to the device, and further executing a step of measuring communication quality in a receiving test unit connected to the receiving device based on the state of reception of the test packet by the receiving device. characterized by

Further, the computer program of the present invention is a wireless communication test for measuring the quality of wireless communication that is performed according to a communication protocol stack having multiple layers, with one of a wireless base station and a wireless terminal as a transmitting device and the other as a receiving device. In order to solve the above problems with respect to the computer program that realizes the function of the device,
a mode selection unit that selects a computer connected to a transmission-side device between a normal mode that allows execution of adaptive modulation and coding control in the physical layer of a communication protocol stack and a test mode that stops the execution; A modulation and coding information acquisition unit that acquires modulation and coding information including the type and coding rate of the frequency modulation method to be set in the physical layer, and the modulation and coding that is acquired when the test mode is selected. A modulation coding information setting unit that fixedly sets the frequency modulation method and coding rate specified by the information to the physical layer via the upper protocol layer, which is a higher protocol layer than the physical layer, and a test mode. Along with the selection, the test packet is transmitted from the upper protocol layer to the receiving side device while the frequency modulation method and coding rate specified in the modulation and coding information are fixedly set in the physical layer. Function as a test packet transmission command center that commands the transmission side device,
A computer program that causes a computer connected to a receiving device to function as a receiving test unit that includes a communication quality measuring section that measures communication quality based on the state of reception of test packets by the receiving device.

In this configuration, of a wireless base station and a wireless terminal that wirelessly communicate according to a communication protocol stack having multiple layers, the transmitting side test unit is connected to the transmitting side, and the receiving side test unit is connected to the receiving side. (During downlink communication, the radio base station is on the transmitting side and the radio terminal is on the receiving side, and vice versa during uplink communication). The transmission-side test unit selects either a normal mode that allows execution of adaptive modulation and coding control in the physical layer, or a test mode that stops the execution, and when the test mode is selected, the physical layer Modulation and coding information including the type of frequency modulation method and coding rate to be set is appropriately acquired, and the frequency modulation method and coding rate specified by the modulation and coding information are transmitted from the upper protocol layer to the physical layer. is fixed, and in this state, the sending side device is instructed to transmit a test packet from the upper protocol layer to the receiving side device.

As a result, the wireless communication test apparatus of the present invention has the following effects.
(1) Since the transmitting side test unit sets the modulation and coding information for the physical layer via the upper protocol layer, the work becomes much easier than when the modulation and coding information is set directly in the physical layer. In addition, since test packet transmission using the above modulation coding information setting is performed via the upper protocol layer, the protocol processing environment during actual use, such as the delay factor when passing through the upper protocol layer, is more accurately reflected. communication test is possible.

(2) Of the radio base station and radio terminal, a test system can be constructed by connecting a transmitting side test unit to the transmitting side and a receiving side test unit to the receiving side. It is possible to incorporate both wireless terminals as target devices into the test at the same time. Therefore, it is possible to directly implement a communication test using an arbitrary combination of base station apparatus and wireless terminal.

Wireless communication is carried out, for example, according to a communication protocol stack specified by 3GPP (Third Generation Partnership Project), and in this case, the modulation coding information is MCS (Modulation Coding Scheme) information.

In the 3GPP specifications, retransmission control is performed by HARQ, but when retransmission control is performed, frequency resources are wasted due to frequently repeated error correction retransmissions, and changes in the number of HARQ retransmissions due to changes in the communication environment. Since the number of redundant bits also varies substantially depending on the MCS setting, it becomes a factor that hinders proper evaluation of throughput and the like according to the MCS setting contents. In this case, the following configuration is effective. That is, in the test mode, execution of retransmission control in the MAC (Media Access Control) layer is further stopped. Then, the transmission side test unit transmits packets using a protocol layer higher than the MAC layer that performs retransmission control as the upper protocol layer. A retransmission control stop setting unit for setting stop of retransmission control is further provided. As a result, as the test mode is selected, the frequency modulation method and coding rate specified in the MCS information are fixedly set in the physical layer, and the upper protocol layer is stopped while retransmission control by the MAC layer is stopped. , the test packet is sent to the receiving device.

An upper protocol layer can be an RRC (Radio Resource Control) layer, and a test mode can be set based on a semi-persistent scheduling (SPS) method. Adaptive modulation and coding control is a component technology of the dynamic scheduling system, but SPS does not dynamically allocate radio resources each time, but rather allocates radio resources semi-persistently. Specifications are defined, and it can be said that this is a very convenient scheduling method for fixedly setting the MCS for the test mode. In addition, since the MCS setting is also performed in the RRC layer that directly describes the radio resource control contents and covers the SPS, the setting work can be further simplified, and the protocol processing environment in actual use is more accurate. can be reflected in the test.

The communication quality measurement unit can be configured to measure throughput when receiving test packets. This makes it possible to easily and accurately evaluate the influence of the test communication environment on the communication speed. In addition, the characteristics to be measured other than throughput include bit error rate, signal to interference power ratio (SIR), and the like.

The modulation and coding information acquisition unit selects the modulation and coding information to be set and the modulation and coding information storage unit that stores a plurality of pieces of MCS information with mutually different combination contents of the type of frequency modulation method and the coding rate. and a modulation coding information selection unit that reads from the modulation coding information storage unit. A plurality of modulation coding information (for example, information described by coding in the corresponding protocol layer) are stored in advance in the modulation coding information storage unit, and are appropriately selected and used to meet the MCS conditions to be tested. Setting and switching can be easily performed when there are a plurality of them.

The wireless base station and wireless terminal can be tested in a wireless communication state via their respective wireless communication units. It is preferable to provide a pseudo-radio-environment constructing section having a main waveguide that is physically connected and a fading simulator arranged on the main waveguide. As a result, various fading states can be pseudo-quantitatively added to the test transmission wave, and the effects of fading on communication quality (for example, throughput characteristics) under fixed MCS setting conditions can be clearly evaluated. becomes possible.

In addition, the pseudo-radio environment construction unit includes a noise superimposition waveguide that merges with the main waveguide via a power divider on the transmission downstream side of the fading simulator, and a white noise generation unit provided on the noise superimposition waveguide. can be configured as further comprising As a result, broadband white noise (background noise) can be added to the test transmission wave in a pseudo and quantitative manner along with the fading conditions, and the effect of white noise on communication quality under fixed MCS setting conditions can be clarified. can be evaluated.

The transmission side test unit and the reception side test unit constitute a base station side comprehensive unit in which the downlink transmission side test unit and the uplink reception side test unit are integrated on the radio base station side. can be provided so as to constitute a terminal-side integrated unit in which the uplink transmission side test unit and the downlink reception side test unit are integrated. Further, a downlink-side pseudo-wireless environment building unit and an uplink-side pseudo-wireless environment building unit can be provided in parallel on the main waveguide as pseudo-wireless environment building units. By doing so, the communication quality measurement test between the radio base station and the radio terminal via the pseudo radio environment construction unit can be performed on both the downlink and the uplink. It can be easily implemented without replacing the wiring.

In this case, a pair of distribution waveguide sections, one for uplink and the other for downlink, can be formed in the intermediate portion of the main waveguide. A downlink-side pseudo-radio-environment constructing unit and an uplink-side pseudo-radio-environment constructing unit are respectively arranged in these distribution waveguide sections, and circulators are respectively arranged at both ends of the distribution waveguide sections. Then, the downlink-side pseudo-radio-environment constructing unit and the uplink-side pseudo-radio-environment constructing unit include a circulator, a fading simulator, and a power divider from the transmission upstream side in each of the uplink and downlink distribution waveguide sections. Arranged in this order, the noise superimposing waveguide merges with the distribution waveguide section via the power divider, and the white noise generating section is arranged on the noise superimposing waveguide. As a result, both end sections of the main waveguide are shared by the downlink and uplink, and the distribution waveguide section forming the intermediate portion is a waveguide section uniquely occupied by the downlink and the uplink, respectively. By arranging circulators at both ends of the distribution waveguide section, when the transmission wave is passing through one distribution waveguide section, the transmission wave leaks to the other distribution waveguide section via the branch point. Loss can be suppressed. In addition, since both end sections of the main waveguide are shared by the downlink and uplink, the number of waveguide connection terminals of the transmission side device and the reception side device can be reduced, and the connection structure can be simplified.

A first isolator is provided on the distribution waveguide section between the power divider and the fading simulator, a second isolator is provided on the noise superimposition waveguide between the power divider and the white noise generator, and further A third isolator can be provided between the circulator and the power divider on the distribution waveguide section, and has a higher attenuation factor than either the first isolator or the second isolator during backward transmission.

When one of the distribution waveguide sections is transmitting the test transmission wave, the additional interference wave component when passing through the fading simulator and the additional noise wave component from the white noise generation section via the power divider will vary depending on the test conditions. Each additional strength must be properly adjusted. However, since the distribution waveguide section and the noise superimposition waveguide form a branch path that can pass in both directions via the power divider, the additional interference wave component is transferred to the noise superimposition waveguide side. There is a possibility that loss due to leaky waves may occur on the output side of the fading simulator in the split waveguide section.

In addition, these leaky waves propagate in the waveguide of the leakage destination and produce reflected waves due to impedance mismatch at the white noise generator or the coupling position with the fading simulator. It may work. In either case, there is a possibility that the intensity setting of the additional interference wave component and the additional noise wave component that meet the test conditions will be adversely affected. Therefore, as described above, the first isolator is provided on the distribution waveguide section between the power divider and the fading simulator, and the second isolator is provided on the noise superimposition waveguide between the power divider and the white noise generator. By providing the above-mentioned leakage loss can be reduced, it becomes easier to adjust the strength of the additional interference wave component and the additional noise wave component to desired values.

On the other hand, the test transmission wave passing through the distribution waveguide section is suppressed from leaking to the other distribution waveguide section by the circulator. However, a directional waveguide component that constitutes a circulator or isolator generally does not have a 100% blocking rate even when passing in the reverse direction, and generates a considerable passing component. Leakage to the other distribution waveguide section via this circulator poses a greater problem in measuring communication quality while adjusting the strength of the test transmission wave to a desired value. Therefore, if a third isolator having a larger attenuation factor during reverse transmission than either the first isolator or the second isolator is provided between the circulator and the power divider on the distribution waveguide section, the power is transmitted through the circulator. Therefore, the loss due to leakage of the test transmission wave component to the other distribution waveguide section side can be kept as small as possible, which greatly contributes to the improvement of the quality of the wireless communication test.

1 is a block diagram showing a configuration example of a wireless communication test apparatus of the present invention together with the concept of protocol stacks in 3GPP specifications for wireless base stations and wireless terminals; FIG. FIG. 3 is a block diagram showing details of a pseudo wireless environment construction unit; 4 is a flowchart showing the flow of mode switching processing; 4 is a flowchart showing the flow of test MCS setting; The figure which shows an example of a downstream SPS process sequence. FIG. 4 is a diagram showing an example of storage contents of MCS information that can be used for a downlink (physical downlink control channel); FIG. 2 is a block diagram showing an example in which the wireless communication test apparatus of the present invention is configured specifically for downlink measurement; FIG. 2 is a block diagram showing an example in which the wireless communication test apparatus of the present invention is configured specifically for uplink measurement; FIG. 2 is a block diagram of a device configuration example of the present invention in which a wireless base station and a wireless terminal are wirelessly connected to perform a test; FIG. 10 is a graph showing an example of downlink throughput measurement when a field test is performed by wirelessly connecting a wireless base station and a wireless terminal using the apparatus of FIG. 9; FIG. 10 is a graph showing another downlink throughput measurement example when a field test is performed by wirelessly connecting a wireless base station and a wireless terminal using the apparatus of FIG. 9 ; FIG. 3 is a diagram showing an example of a reference channel for measurement of a physical downlink control channel specified in 3GPP specification: 36.521; FIG. 3 is a diagram showing an example of a reference channel for measurement of a physical uplink control channel specified in 3GPP specification: 36.141; FIG. FIG. 2 shows a conventional test system using a pseudo base station tester;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a block diagram showing the overall configuration of a wireless communication test device that is an embodiment of the present invention. In the wireless communication test apparatus 1, the objects to be measured for communication quality are a wireless base station 70 and a wireless terminal 80 such as a mobile phone or smart phone that wirelessly communicates with the wireless base station. Wireless communication is implemented according to a communication protocol stack having multiple layers defined by 3GPP (Third Generation Partnership Project). communication is employed. Also, the radio base station 70 is configured as an eNodeB, which is a base station adopted for LTE, and the radio terminal 80 is also configured as an LTE compatible device.

The wireless communication test apparatus 1 performs communication quality measurement using one of the wireless base station 70 and the wireless terminal 80 as a transmitting side apparatus and the other as a receiving side apparatus (during downlink communication measurement, the wireless base station 70 is the transmitting side apparatus). , the wireless terminal 80 is the receiving side, and vice versa when measuring uplink communication). Specifically, the base station side general unit 10 connected to the radio base station 70 side, the terminal side general unit 20 connected to the radio terminal 80 side, and the radio base station 70 and the radio terminal 80 are connected in a wired form. A pseudo wireless environment forming unit 30 that intervenes in a form of connection and creates a pseudo wireless communication quality deterioration factor such as radio wave interference (fading) and noise superimposition that are assumed to occur between the two during wireless communication. Including as

Here, the base station side general unit 10 integrally realizes the function of the downlink transmission side test unit and the function of the uplink reception side test unit, and the terminal side general unit 20 performs the uplink transmission side test. It integrates the function of the unit and the function of the downlink receiver side test unit. Both integrated units 10 and 20 are provided with computer hardware such as a personal computer (PC), and implement the function of a test unit by software. Since they have the same basic configuration, the base station side general unit 10 will be explained, and the terminal side general unit 20 will be assigned the same reference numerals as the base station side general unit 10. Details are omitted unless otherwise specified.

The base station side integrated unit 10 includes a CPU 11 as a main processing unit, a RAM 12 as its work area, a ROM 13 for storing basic control programs such as computer device control, and software for realizing the basic functions of the base station side integrated unit 10. A hard disk drive 14 for storing data and data, an input/output unit 15, and a bus 16 for interconnecting them are main parts. The input/output unit 15 includes an input unit 18 (keyboard, touch panel, mouse, etc.) for inputting settings and selecting functions required for communication quality measurement, and a monitor 17 (for displaying measurement menus, measurement results, etc.). A display control interface (not shown) is connected.

The hard disk drive 14 stores function implementation software 50 for the transmission side test unit and function implementation software 60 for the reception side test unit. The function realization software 50 of the transmission side test unit performs adaptive modulation and coding control in the communication protocol stack of the transmission side device (here, the wireless base station 70; in the terminal side integrated unit 20, the wireless terminal 80) from the physical layer. is programmed to instruct the transmitting side device to transmit a packet in the upper protocol layer, which is the RRC layer in this embodiment. An overview of the communication protocol stack adopted by 3GPP will be briefly described below.

In FIG. 1, each block showing the radio base station 70 and the radio terminal 80 shows an outline of the C-Plane protocol stack structure related to the communication quality test. Both include a physical (PHY) layer, a MAC (Medium Access Control) layer, an RLC ((Radio Link Control) layer, a PDCP (Packet Data Convergence Protocol) layer, and an RRC (Radio Resource Control) layer from the lower side. The PHY layer is also called layer 1 (L1), the MAC layer, RLC layer and PDCP layer are also called data link layer or layer 2 (L2), and the RRC layer is layer 2 (L2). 3 (L3) The physical layer is responsible for modulation scheme, coding scheme, antenna multiplexing, etc. The MAC layer is responsible for radio resource allocation, data mapping, retransmission control, etc. The RLC layer is responsible for retransmission control. , duplicate detection, ordering, etc. The PDCP layer is responsible for IP packet header compression, decompression, encryption, etc.

The RRC layer is responsible for system notification information delivery, earthquake early warning delivery, paging delivery, NAS message delivery, handover control, and transmission control of basic parameters for semi-persistent scheduling (SPS). The SPS performs switching between the normal mode and the test mode, and related switching control for permitting/prohibiting adaptive modulation and coding control and permitting/prohibiting retransmission control.

Next, the function implementation software 50 of the sending test unit has a mode switching program 51 . The mode switching program 51 selects either a normal mode that allows execution of adaptive modulation and coding control in the physical layer or a test mode that similarly stops the execution, based on a selection input from the input unit 18. Implements the function of the mode selection section. The function realization software 50 also has an MCS setting program 52 . When the test mode is selected, the MCS setting program 52 selects one of a plurality of pre-stored test MCS module groups 53 based on selection input from the input unit 18, and based on the selection, physical MCS information acquisition unit 52A ( FIG. 4 : S11) that acquires MCS information (modulation coding information) including the type and coding rate of the frequency modulation method to be set in the layer, the frequency specified by the acquired MCS information An MCS setting unit 52B ( FIG. 4 : S12) that permanently sets the modulation scheme and coding rate to the physical layer via the RRC layer (upper protocol layer), and retransmission that sets permission or stop of retransmission control Each function of the control stop setting section 52C (FIG. 4: S13) is implemented.

FIG. 8 shows, as an example of the test MCS module group 53, MCS information that can be adopted for the downlink (physical downlink control channel). This is the same as defined in 3GPP specification 36.213 and includes 32 types of MCS setting conditions. Of these, the MCS setting conditions of numbers 0 to 28 in the MCS index are set to a fixed frequency modulation method and packet data size. 3GPP adopts the HARQ code correction method, and the redundant bit addition process expands the packet data size according to the reciprocal of the coding rate. Therefore, the packet data size uniquely corresponds to the coding rate. Then, when the MCS setting conditions of numbers 0 to 28 are selected in the test mode, retransmission control in which the coding rate fluctuates is also stopped. Note that the terminal-side general unit 20 stores a test MCS module group 53 including MCS information that can be used for the uplink (physical uplink control channel). On the other hand, for numbers 29 to 31 in the MCS index, although the frequency modulation method is similarly fixed, the packet data size (encoding rate) is allowed to fluctuate, and is in test mode where retransmission control is executed. used.

Returning to FIG. 1, the test packet transmission command program 54 is included in the function implementation software 50 of the transmission side test unit. When the test mode is selected, the program 54 performs a test from the RRC layer to the receiving side device while the frequency modulation method and coding rate defined in the MCS information are fixedly set in the physical layer PHY. It implements the function of the Test Packet Send Command, which commands the sending device to send a packet. A measurement program 61 is included in the function implementation software 60 of the receiving side test unit. The program 61 is a communication quality measurement unit that measures communication quality (for example, measurement and calculation of throughput, bit error rate, desired wave power signal to interference power ratio, etc.) based on the reception state of the test packet by the receiving device. to realize the function of The function realizing software 60 also stores a measurement data output program 62 for outputting the measurement data.

Next, FIG. 2 is a block diagram showing the details of the pseudo-radio environment forming section 30. As shown in FIG. The radio base station 70 and the radio terminal 80 are wiredly connected by a main waveguide 31 such as a coaxial cable, and the pseudo radio environment forming section 30 is arranged on the main waveguide 31 . Specifically, a distribution waveguide section 32 for downlink and a distribution waveguide section 33 for uplink are formed in the intermediate portion of the main waveguide 31, and these distribution waveguide sections 32 and 33 are formed on the downlink side. A pseudo radio environment forming section 30D and an uplink side pseudo radio environment forming section 30U are installed in parallel. Circulators 34 and 34 are arranged at both ends (branch points) of the distribution waveguide sections 32 and 33, respectively. The connection forward direction of each circulator 34, 34 is indicated by an arc-shaped arrow in the figure. It is easy to obtain commercially available products that ensure power in the range of 60 W or more and 150 W or less, have an isolation (reverse direction loss) value of 15 dB or more and 25 dB or less, and have an insertion loss of 0.5 dB or less. Yes, it can be preferably employed in the present invention.

The downlink pseudo radio environment forming unit 30D and the uplink pseudo radio environment forming unit 30U have the same hardware configuration. A circulator 34, a fading simulator 41, and a power divider 43 are arranged in this order from the transmission upstream side, and a noise superimposition waveguide 49 merges with the distribution waveguide sections 32 and 33 via the power divider 43. A white noise generator 42 is arranged on the waveguide 49 for the signal. The white noise generation unit 42 is configured as a source of additive Gaussian white noise (AWGN), for example. there is The fading simulator 41 is a well-known device that simulates modulation such as Rayleigh fading, Rician fading, and Doppler shift for the input wave. An attenuator 48 is inserted upstream of the fading simulator 41 to adjust the input intensity of the test packet transmission wave.

A first isolator 44 is provided on the distribution waveguide sections 32, 33 between the power divider 43 and the fading simulator 41, and a noise superimposing waveguide 49 is provided between the power divider 43 and the white noise generator 42. A second isolator 45 is provided above. Between the circulator and the power divider 43 on the distribution waveguide sections 32 and 33, there is a third isolator 46 which has a larger attenuation factor than either the first isolator 44 or the second isolator 45 during reverse transmission. is provided. The connection forward direction of each isolator 44 to 46 is indicated by an arrow in the figure. The range of 150 W or less can be secured, the isolation (reverse direction loss) value is 15 dB or more and 25 dB or less, and the insertion loss is 0.5 dB or less. . In this embodiment, the first isolator 44 and the second isolator 45 are of the same specification (isolation value is, for example, 20 dB), and the third isolator 46 is the same as the first isolator 44 and the second isolator 45. A larger isolation value than the first isolator 44 and the second isolator 45 as a whole is ensured by cascading a plurality of (two in FIG. 3) element isolators 46A and 46B (with an isolation value of, for example, 20 dB) according to the specifications. I am trying to

The operation and usage of the wireless communication test device 1 will be described below.
First, the radio base station 70 and the radio terminal 80 to be measured are incorporated into the radio communication test apparatus 1 as shown in FIGS. In the downlink test, the base station side integrated unit 10 starts up the mode selection program 51 . FIG. 3 is a flow chart showing the flow of processing at that time. At S1, the user selects either the test mode or the normal mode by mode selection input from the input unit 18. FIG. In S2, the content of the selection is judged, and either the test mode or the normal mode is set according to the judgment result.

Subsequently, the user selects the MCS condition to be set based on the input from the input unit 18 using, for example, the MCS index shown in FIG. Then, the MCS setting program 52 is launched together with the test MCS module 53 (FIG. 1) of the selected index. FIG. 4 is a flow chart showing the flow of processing at that time. In S11, the modulation scheme and packet data size (encoding rate) corresponding to the index are selected and read. Also, in S12, the modulation method and packet data size (encoding rate) are set. Further, when indexes 0 to 28 are selected, stop of retransmission control is set in S13. On the other hand, indexes 29-31 allow execution of retransmission control.

The above contents are transmitted to the radio base station 70, and the MCS setting (and the presence or absence of retransmission control) is commanded to the RRC layer of the protocol stack. On the radio base station 70 side, setting according to semi-persistent scheduling (SPS) for test mode radio communication with the radio terminal 80 is made in the RRC layer. FIG. 5 shows an example of a downlink SPS processing sequence in LTE (uplink processing is the same except for the data transmission direction). First, in S101, the radio base station 70 notifies the radio terminal 80 of basic parameters in SPS. The notification of S101 is transmitted and received via a physical downlink shared channel (PDSCH) by an RRC signal, which is RRC layer signaling. The SPS parameters notified by the RRC signal in S101 include, for example, the SPS communication interval. The radio base station 70 can set the SPS communication interval in units of subframes (1 msec). Note that the RRC signal of S101 only notifies the basic parameters of the SPS, and the transmission/reception based on the SPS is not started at the timing based on this RRC signal.

Next, in S102, the radio base station 70 transmits to the radio terminal 80 a control signal for activating the SPS. The control signal of S102 is transmitted and received through a physical downlink control channel (PDCCH) by DCI (Downlink Control Information), which is physical layer signaling. The control signal of S102 activates the SPS whose basic parameters are set by the RRC signal of S101, and transmission/reception based on the SPS is started. The DCI, which corresponds to the control signal of S102, contains parameters necessary for executing the SPS. The parameters included in DCI are the designation of radio resources corresponding to PDSCH (PUSCH in the case of uplink) in each subframe in which SPS-based transmission is performed, and the MCS applied to SPS-based transmission, that is, the fixed specification of the frequency modulation method and coding rate, and specification of the presence or absence of retransmission control. Then, from S103 to S109, the radio terminal 80 performs SPS-based transmission via PDSCH (PUSCH in the case of uplink) without using special signaling. After the transmission of the test packet is completed, the radio base station 70 transmits a control signal for releasing the SPS to the radio terminal 80 in S110. The control signal in S110 is transmitted/received via PDSCH by DCI in the same manner as in S102. The SPS activated in S103 is released by the control signal of S110, and transmission/reception based on the SPS is terminated.

On the other hand, in the terminal-side integrated unit 20 shown in FIG. 1, a measurement program 61 and a measurement data output program 62 are started in advance. Then, while monitoring the state of reception of the test packet by the wireless terminal 80, the throughput and the like are measured. A desired MCS setting information is selected from prepared MCS setting information, and a setting command is issued to the RRC layer, which is an upper protocol layer, to set the MCS for the physical layer. Therefore, it is clear that the work is much easier than when the MCS is directly set in the physical layer. In addition, since the transmission of test packets by the above MCS settings is performed via the RRC layer, which is layer 3, the protocol processing environment during actual use, such as delay factors when passing through the following protocol layers, is more accurate. Reflected communication test is possible. Furthermore, since both the radio base station 70 and the radio terminal 80 can be simultaneously incorporated into the test as target equipment, a communication test can be directly implemented using any combination of the base station apparatus and the radio terminal 80 .

When performing an uplink test, the terminal-side general unit 20 side selects the test mode and sets the MCS, and the base-station-side general unit 10 side launches the measurement program. can be fixed. According to the hardware configuration of FIGS. 1 and 3, the downlink test and the uplink test can be performed in exactly the same way without changing the connection by replacing the communication equipment between the transmitting side and the receiving side. Convenient.

The pseudo-radio environment forming unit 30 has the following advantages by adopting the hardware configuration shown in FIG. That is, both end sections of the main waveguide 31 are used as common sections for the downlink and the uplink, and the distribution waveguide sections 32 and 33 forming the intermediate portion are used as waveguide sections uniquely occupied by the downlink and the uplink, respectively. ing. The circulators 34, 34 are arranged at both ends of the distribution waveguide sections 32, 33, so that when the test packet transmission wave is passing through one of the distribution waveguide sections 32, 33, the other distribution waveguide section 32, 33 passes through the branch point. Leakage and loss of transmission waves in the distribution waveguide sections 32 and 33 can be suppressed. In addition, by sharing both end sections of the main waveguide 31 for the downlink and the uplink, the number of waveguide connection terminals of the transmission side device and the reception side device is reduced, and the connection structure is simplified. .

When the test packet transmission wave is being transmitted in one of the distribution waveguide sections 32 and 33, the additional interference wave component when passing through the fading simulator 41 and the white noise generator 42 via the power divider 43 It is necessary to properly adjust the added intensity of each additional noise wave component according to the test conditions. However, since the distribution waveguide sections 32 and 33 and the noise superimposition waveguide 49 form a bidirectional branch path through the power divider 43, the additional interference wave component is generated on the noise superimposition waveguide 49 side. Moreover, the additional noise wave component may cause loss due to leaky waves on the output side of the fading simulator 41 in the distribution waveguide sections 32 and 33, respectively.

In addition, these leaky waves propagate in the waveguide of the leakage destination and produce reflected waves due to impedance mismatch at the coupling position with the white noise generator 42 or the fading simulator 41, and these reflected waves are unwanted noises in the test. It can also act as a component. In either case, there is a possibility that the intensity setting of the additional interference wave component and the additional noise wave component that meet the test conditions will be adversely affected. However, in the above configuration, the first isolator 44 is provided on the distribution waveguide sections 32, 33 between the power divider 43 and the fading simulator 41, and noise is superimposed between the power divider 43 and the white noise generator 42. Since the second isolator 45 is provided on the optical waveguide 49, the above-mentioned leakage loss can be reduced, making it easier to adjust the strength of the additional interference wave component and the additional noise wave component to desired values. .

On the other hand, the circulator 34 suppresses the test transmission wave passing through the distribution waveguide section (eg, reference numeral 32) from leaking to the other distribution waveguide section (eg, reference numeral 33). However, the directional waveguide components that constitute the circulator 34 and the isolators 44 to 46 do not have a 100% blocking rate even when passing in the reverse direction, and a considerable passing component is generated. However, between the circulator 34 and the power divider 43 on the distribution waveguide sections 32 and 33, a third isolator 46 having a larger attenuation factor than either the first isolator 44 or the second isolator 45 during reverse transmission is provided. By providing the circulator 34, the loss caused by the leakage of the test transmission wave component to the other distribution waveguide section 32, 33 side is greatly reduced, contributing to the improvement of the quality of the wireless communication test.

Although the wireless communication test apparatus 1 of FIG. 1 is provided with the pseudo radio environment forming section 30D and the pseudo radio environment forming section 30U separately for the downlink and the uplink, one of them is omitted as shown in FIG. It is also possible to configure the wireless communication test device 100 . In this case, the transmitting side test unit 10 omits the function realizing software of the receiving side test unit, and the receiving side test unit 20 omits the function realizing software of the transmitting side test unit. Also, since no branch waveguide section is formed in the main waveguide 31, the circulator is also omitted. As shown in FIG. 7, the downlink test is performed by connecting the radio base station 70 to the transmitting side and the radio terminal 80 to the receiving side. Also, as shown in FIG. 8, an uplink test is performed by connecting a wireless terminal 80 to the transmitting side and a wireless base station 70 to the receiving side.

Furthermore, if it is desired to conduct a field test in an outdoor wireless communication environment, like the wireless communication test apparatus 200 in FIG. Just plug it in and do the same test.

FIG. 10 shows the condition of MCS index 7 (modulation method: QPSK) and the condition of MCS index 14 (modulation method: 16QAM) in FIG. and MCS index 17 conditions (modulation scheme: 646QAM). FIG. 11 also shows an example of uplink throughput measurement under the conditions of MCS index 8 (modulation scheme: QPSK) and MCS index 15 (modulation scheme: 16QAM) of FIG. both. It can be seen that by fixing the modulation scheme, the throughput characteristics can be evaluated under each MCS condition.

Although the embodiment of the present invention has been described above, it is merely an example, and the present invention is not limited to this.

10 base station side integrated unit 18 input section (mode selection section, MCS information selection section)
20 terminal-side integrated unit 30 pseudo-radio environment forming unit 30D downlink-side pseudo-radio environment forming unit 30U uplink-side pseudo-radio environment forming unit 31 main waveguides 32, 33 distribution waveguide section 34 circulator 41 fading simulator 42 white noise generator 43 Power divider 44 First isolator 45 Second isolator 46 Third isolator 49 Noise superimposing waveguide 50 Function realization program 52 of transmission side unit MCS setting program 52A MCS information acquisition unit 52B MCS setting unit 52C Retransmission control stop setting unit 53 Test MCS Module (MCS information storage unit)
54 Test Packet Transmission Command Program (Test Packet Transmission Command)
60 Function implementation program for receiving side test unit 61 Measurement program (communication quality measurement unit)
70 wireless base station 80 wireless terminal

Claims (9)

In a wireless communication test device for measuring the quality of wireless communication implemented according to a communication protocol stack having multiple layers, with one of a wireless base station and a wireless terminal as a transmitting device and the other as a receiving device,
a mode selection unit connected to the transmission-side device for selecting either a normal mode that allows execution of adaptive modulation and coding control in the physical layer of the communication protocol stack or a test mode that stops the execution; A modulation and coding information acquisition unit that acquires modulation and coding information including the type and coding rate of the frequency modulation method to be set in the physical layer; and the modulation that is acquired when the test mode is selected. Modulation coding information setting for fixedly setting the frequency modulation method and the coding rate specified by the coding information to the physical layer via an upper protocol layer that is a higher protocol layer than the physical layer and when the test mode is selected, the frequency modulation method and the coding rate defined in the modulation and coding information are fixedly set in the physical layer, and from the upper protocol layer to the a test packet transmission command unit for commanding the transmitting device to transmit a test packet to a receiving device;
a receiving side test unit connected to the receiving side device and including a communication quality measuring unit that measures communication quality based on the reception state of the test packet by the receiving side device;
a pseudo-radio environment constructing unit having a main waveguide that connects the radio base station and the radio terminal in a wired manner, and a fading simulator arranged on the main waveguide;
The receiving side test unit and the transmitting side test unit corresponding to the receiving side test unit are on the base station side where the downlink transmitting side test unit and the uplink receiving side test unit are integrated at the radio base station side. While constituting a general unit, a terminal side general unit is constituted by integrating an uplink transmission side test unit and a downlink reception side test unit on the wireless terminal side,
A downlink-side pseudo-radio environment building unit and an uplink-side pseudo-radio environment building unit are provided in parallel on the main waveguide as the pseudo-radio environment building unit,
In the test mode, execution of retransmission control in the MAC (Media Access Control) layer is further stopped,
The transmission-side test unit transmits packets using a protocol layer higher than the MAC layer that performs the retransmission control as the upper protocol layer,
A pair of distribution waveguide sections, one for uplink and the other for downlink, are formed in an intermediate portion of the main waveguide. A pseudo wireless environment construction unit is arranged, and circulators are arranged at both ends of the distribution waveguide section,
The downlink-side pseudo-radio-environment constructing unit and the uplink-side pseudo-radio-environment constructing unit, in each of the distribution waveguide sections for the uplink and the downlink, respectively, from the transmission upstream side, the circulator, the fading Assuming that the simulator and the power divider are arranged in this order, the noise superimposition waveguide joins the distribution waveguide section via the power divider, and the white noise generating section is arranged on the noise superimposition waveguide A first isolator is provided on the distribution waveguide section between the power divider and the fading simulator, and the noise superimposition guide is provided between the power divider and the white noise generator. A second isolator is provided on the waveguide, and further, between the circulator and the power divider on the distribution waveguide section, the attenuation rate during reverse transmission is equal to that of the first isolator and the second isolator. A third isolator is provided which is larger than either
A wireless communication test device characterized by: 2. A wireless communication test apparatus according to claim 1, wherein said wireless communication is carried out according to a communication protocol stack defined by 3GPP (Third Generation Partnership Project), and said modulation coding information is MCS (Modulation Coding Scheme) information. . 3. The wireless communication test apparatus according to claim 2, wherein the transmission - side test unit includes a retransmission control stop setting section that sets the MAC layer to stop the retransmission control when the test mode is selected. . 4. The radio communication test apparatus according to claim 2, wherein said upper protocol layer is an RRC (Radio Resource Control) layer, and said test mode is set based on a semi-persistent scheduling method. 5. The wireless communication test apparatus according to any one of claims 1 to 4, wherein said communication quality measuring unit measures throughput when said test packet is received. The modulation and coding information acquisition unit includes a modulation and coding information storage unit that stores a plurality of pieces of modulation and coding information having mutually different combinations of the type of the frequency modulation method and the coding rate, and a modulation and coding to be set. 6. The wireless communication test apparatus according to any one of claims 1 to 5, further comprising an MCS information selection unit that selects information and reads it from the modulation and coding information acquisition unit. The pseudo-radio environment construction unit includes a noise superimposition waveguide that merges with the main waveguide via a power divider on the transmission downstream side of the fading simulator, and a white noise generation unit provided on the noise superimposition waveguide. The wireless communication test device of claim 1 , further comprising: A wireless communication test method in a wireless communication test apparatus for measuring the quality of wireless communication performed according to a communication protocol stack having multiple layers, with one of a wireless base station and a wireless terminal as a transmitting side device and the other as a receiving side device There is
In the wireless communication test equipment,
a mode selection unit connected to the transmission-side device for selecting either a normal mode that allows execution of adaptive modulation and coding control in the physical layer of the communication protocol stack or a test mode that stops the execution; A modulation and coding information acquisition unit that acquires modulation and coding information including the type and coding rate of the frequency modulation method to be set in the physical layer; and the modulation that is acquired when the test mode is selected. Modulation coding information setting for fixedly setting the frequency modulation method and the coding rate specified by the coding information to the physical layer via an upper protocol layer that is a higher protocol layer than the physical layer and when the test mode is selected, the frequency modulation method and the coding rate defined in the modulation and coding information are fixedly set in the physical layer, and from the upper protocol layer to the a test packet transmission command unit for commanding the transmitting device to transmit a test packet to a receiving device;
a receiving side test unit connected to the receiving side device and including a communication quality measuring unit that measures communication quality based on the reception state of the test packet by the receiving side device;
a pseudo-radio environment constructing unit having a main waveguide that connects the radio base station and the radio terminal in a wired manner, and a fading simulator arranged on the main waveguide;
The receiving side test unit and the transmitting side test unit corresponding to the receiving side test unit are on the base station side where the downlink transmitting side test unit and the uplink receiving side test unit are integrated at the radio base station side. While constituting a general unit, a terminal side general unit is constituted by integrating an uplink transmission side test unit and a downlink reception side test unit on the wireless terminal side,
A downlink-side pseudo-radio environment building unit and an uplink-side pseudo-radio environment building unit are provided in parallel on the main waveguide as the pseudo-radio environment building unit,
In the test mode, execution of retransmission control in the MAC (Media Access Control) layer is further stopped,
The transmission-side test unit transmits packets using a protocol layer higher than the MAC layer that performs the retransmission control as the upper protocol layer,
A pair of distribution waveguide sections, one for uplink and the other for downlink, are formed in an intermediate portion of the main waveguide. A pseudo wireless environment construction unit is arranged, and circulators are arranged at both ends of the distribution waveguide section,
The downlink-side pseudo-radio-environment constructing unit and the uplink-side pseudo-radio-environment constructing unit, in each of the distribution waveguide sections for the uplink and the downlink, respectively, from the transmission upstream side, the circulator, the fading Assuming that the simulator and the power divider are arranged in this order, the noise superimposition waveguide joins the distribution waveguide section via the power divider, and the white noise generating section is arranged on the noise superimposition waveguide A first isolator is provided on the distribution waveguide section between the power divider and the fading simulator, and the noise superimposition guide is provided between the power divider and the white noise generator. A second isolator is provided on the waveguide, and further, between the circulator and the power divider on the distribution waveguide section, the attenuation rate during reverse transmission is equal to that of the first isolator and the second isolator. A third isolator is provided, which is larger than any of the
selecting a test mode for stopping execution of adaptive modulation and coding control in a physical layer of the communication protocol stack, in the test packet transmission command unit connected to the transmitting device; a step of obtaining modulation and coding information including a type of frequency modulation method and a coding rate; a step of fixedly setting the physical layer via an upper protocol layer, which is a higher protocol layer; and transmitting a test packet from the upper protocol layer to the receiving device in the state where the receiving device is set to and measuring communication quality based on the state of reception of the test packet by the device. A computer that realizes the function of a wireless communication test device for measuring the quality of wireless communication implemented according to a communication protocol stack having multiple layers, with one of a wireless base station and a wireless terminal as a transmitting device and the other as a receiving device. a program,
In the wireless communication test equipment,
One of the radio base station and the radio terminal is a transmitting side device and the other is a receiving side device,
a mode selection unit connected to the transmission-side device for selecting either a normal mode that allows execution of adaptive modulation and coding control in the physical layer of the communication protocol stack or a test mode that stops the execution; A modulation and coding information acquisition unit that acquires modulation and coding information including the type and coding rate of the frequency modulation method to be set in the physical layer; and the modulation that is acquired when the test mode is selected. Modulation coding information setting for fixedly setting the frequency modulation method and the coding rate specified by the coding information to the physical layer via an upper protocol layer that is a higher protocol layer than the physical layer and when the test mode is selected, the frequency modulation method and the coding rate defined in the modulation and coding information are fixedly set in the physical layer, and from the upper protocol layer to the a test packet transmission command unit for commanding the transmitting device to transmit a test packet to a receiving device;
a receiving side test unit connected to the receiving side device and including a communication quality measuring unit that measures communication quality based on the reception state of the test packet by the receiving side device;
a pseudo-radio environment constructing unit having a main waveguide that connects the radio base station and the radio terminal in a wired manner, and a fading simulator arranged on the main waveguide;
The receiving side test unit and the transmitting side test unit corresponding to the receiving side test unit are on the base station side where the downlink transmitting side test unit and the uplink receiving side test unit are integrated at the radio base station side. While constituting a general unit, a terminal side general unit is constituted by integrating an uplink transmission side test unit and a downlink reception side test unit on the wireless terminal side,
A downlink-side pseudo-radio environment building unit and an uplink-side pseudo-radio environment building unit are provided in parallel on the main waveguide as the pseudo-radio environment building unit,
In the test mode, execution of retransmission control in the MAC (Media Access Control) layer is further stopped,
The transmission-side test unit transmits packets using a protocol layer higher than the MAC layer that performs the retransmission control as the upper protocol layer,
A pair of distribution waveguide sections, one for uplink and the other for downlink, are formed in an intermediate portion of the main waveguide. A pseudo wireless environment construction unit is arranged, and circulators are arranged at both ends of the distribution waveguide section,
The downlink-side pseudo-radio-environment constructing unit and the uplink-side pseudo-radio-environment constructing unit, in each of the distribution waveguide sections for the uplink and the downlink, respectively, from the transmission upstream side, the circulator, the fading Assuming that the simulator and the power divider are arranged in this order, the noise superimposition waveguide joins the distribution waveguide section via the power divider, and the white noise generating section is arranged on the noise superimposition waveguide A first isolator is provided on the distribution waveguide section between the power divider and the fading simulator, and the noise superimposition guide is provided between the power divider and the white noise generator. A second isolator is provided on the waveguide, and further, between the circulator and the power divider on the distribution waveguide section, the attenuation rate during reverse transmission is equal to that of the first isolator and the second isolator. A third isolator is provided, which is larger than any of the
A mode selection unit that selects a computer connected to the transmission-side device between a normal mode that allows execution of adaptive modulation and coding control in the physical layer of the communication protocol stack and a test mode that stops the execution. and the modulation and coding information acquisition unit for acquiring modulation and coding information including the type and coding rate of the frequency modulation method to be set in the physical layer, and the acquisition when the test mode is selected fixedly setting the frequency modulation method and the coding rate specified by the modulation and coding information received to the physical layer via an upper protocol layer, which is a higher protocol layer than the physical layer; a modulation and coding information setting unit, with the frequency modulation method and the coding rate defined in the modulation and coding information being fixedly set in the physical layer as the test mode is selected, the functioning as the test packet transmission command section for commanding the transmission side device to transmit a test packet from an upper protocol layer to the reception side device;
A computer connected to the receiving side device functions as the receiving side test unit including a communication quality measuring unit that measures communication quality based on the reception state of the test packet by the receiving side device. computer program to

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