JP2002237777A - Base station simulator and transmission power control performance testing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To confirm performance of downlink transmission power control of a closed loop to mobile station equipment at a state close to fading environment on an actual radio propagation path. SOLUTION: Control information of downlink transmission power is decided from an uplink signal from the mobile station equipment by a gain control part 108, the downlink transmission power is controlled by using the control information, amplitude fluctuation equivalent to the fading in the radio propagation path is generated by a two-dimensional gauss noise generating part 109 and a downlink transmission signal the power of which is controlled by the control information is multiplied by the amplitude fluctuation equivalent to the fading by a multiplying part 107. The amplitude fluctuation and the control information are stored in a data storage part 110 by correlating them by every one of the same sampling time and whether or not the control information of the downlink transmission power follows the amplitude fluctuation equivalent to the fading is judged by comparing the stored amplitude fluctuation equivalent to the fading with the control information of the downlink transmission power by every one of the same sampling time by a control part 111.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base station simulator and a transmission power control performance test method for performing tests such as performance evaluation and failure judgment of a mobile station such as a portable telephone.

[0002]

2. Description of the Related Art Conventionally, this type of base station simulator and transmission power control performance test method are disclosed in
There is one described in JP-A-220435.

FIG. 7 is a block diagram showing a configuration of a mobile communication system using a conventional base station simulator.

The mobile communication system shown in FIG. 7 includes a base station simulator 701 and a plurality of mobile stations (M
S) 702 to 704 and the base station simulator 701
Control device such as a personal computer (P
C) 705.

[0005] The base station simulator apparatus 701 has a function of enabling a connection test of each of the mobile station apparatuses 702 to 704 and a sequence operation check in accordance with the system standard.
It is configured as shown in FIG.

That is, the base station simulator 701
A demodulation unit 801 that frequency-converts and demodulates uplink signals from the mobile station devices 702 to 704, a channel codec unit 802 that performs decomposition / assembly of uplink / downlink data and code / decode of error correction, and modulates downlink signals. Then, a modulator 804 for frequency conversion, an interface 803 as an interface for voice and various services, and information on a control channel from the mobile station devices 702 to 704 are processed in accordance with the standard of the communication system, and each component of the base station simulator 701 is processed. And a control unit 805 for performing the above control.

On the other hand, as a mobile communication system, C
There is a DMA (Code Division Multiple Access) system, in which a plurality of channels are multiplexed on the same frequency, so that mobile station devices (for example, 702 and 703) interfere with each other.

The transmission power is suppressed for a mobile station device (eg, 702) having a strong radio wave near the base station simulator device 701, and the transmission power is increased for a mobile station (eg, 704) having a weak radio wave. The communication quality can be kept constant.

[0009] Transmission power control includes uplink and downlink transmission power control, and there are open loop and closed loop systems. In the case of closed loop downlink transmission power control, the base station simulator 701 extracts transmission power control information (for example, information indicating that 1 dB transmission power is increased) transmitted from the mobile station devices 702 to 704, and performs downlink transmission. Control power. In the radio propagation path of mobile communication, received power fluctuates due to fading or the like, and transmission power control needs to follow a level fluctuation such as fading.

[0010]

However, in the conventional device, it is difficult to create a fading environment in a simulated manner. Therefore, it is difficult to determine whether closed loop downlink transmission power control is properly performed in the fading environment. There is a problem that there is no function to confirm

[0011] The evaluation of the transmission power control function for the mobile station device in a fading environment can be performed by using a pseudo propagation path such as a fading simulator and confirming the transmission characteristics. However, since the transmission characteristics include many factors such as the performance of the radio section of the device, there are insufficient points to confirm the performance of only transmission power control, and the transient response characteristics should be evaluated. Was difficult.

As another method, the performance of the transmission power control can be confirmed also by varying the reception power of the mobile station device with the attenuator and measuring the transmission power of the base station simulator device at that time. However, in this case, it is difficult to confirm the response to fast fading, and C
In the case of the DMA system, it is difficult to measure the power of a specific physical channel when a plurality of mobile station devices are connected to the base station device or because a common control physical channel is multiplexed on the same frequency. there were.

The present invention has been made in view of the above point, and it is desirable to confirm the performance of closed-loop downlink transmission power control for a mobile station apparatus in a state close to a fading environment in an actual radio propagation path. It is an object of the present invention to provide a base station simulator apparatus and a transmission power control performance test method that can be performed.

[0014]

A base station simulator apparatus of the present invention determines control information of downlink transmission power from an uplink signal from a mobile station apparatus, and uses the control information of downlink transmission power to reduce downlink transmission power. Gain control means for controlling, generation means for generating amplitude fluctuation corresponding to fading of a radio propagation path, and multiplication for multiplying a downlink transmission signal whose power is controlled by the gain control means by amplitude fluctuation corresponding to the fading. Means is provided.

According to this configuration, it is possible to pseudo-add an amplitude change corresponding to fading to the downlink transmission signal transmitted to the mobile station apparatus.

[0016] In the base station simulator of the present invention, in the above configuration, storage means for storing amplitude fluctuation corresponding to fading and control information of downlink transmission power in correspondence with each same sampling time, and storing in this means. The amplitude fluctuation corresponding to the fading and the control information of the downlink transmission power are compared for each of the same sampling times,
A control unit for determining whether or not the control information of the downlink transmission power follows amplitude fluctuation corresponding to the fading.

According to this configuration, it is possible to confirm whether or not downlink transmission power control for the mobile station apparatus is normally performed in a fading environment. That is,
If the above is followed, it means that the downlink transmission power control is performed normally.

In the base station simulator of the present invention, the generation means stores the pattern of the amplitude fluctuation corresponding to the fading and generates the amplitude fluctuation corresponding to the fading of the stored pattern. .

According to this configuration, since a fading environment of an arbitrary pattern can be determined, it is possible to compare and confirm characteristics of transmission power control for each mobile station under the same conditions.

A base station simulator according to the present invention determines gain control means for determining downlink transmission power from an uplink signal from a mobile station, and controls downlink transmission power using the downlink transmission power control information. Generating means for generating an amplitude variation corresponding to multipath fading of a radio propagation path, and a multiplication means for multiplying a downlink transmission signal whose power is controlled by the gain control means by an amplitude variation corresponding to the multipath fading. Delay means for delaying the downlink transmission signal from this means by a delay time for each path in the multipath.

According to this configuration, it is possible to pseudo-add an amplitude variation corresponding to multipath fading to the downlink transmission signal transmitted to the mobile station apparatus.

In the base station simulator of the present invention, in the above-mentioned configuration, the storage means for storing the amplitude fluctuation corresponding to multipath fading and the control information of the downlink transmission power in association with each same sampling time, and this means. The amplitude fluctuation corresponding to the multipath fading and the control information of the downlink transmission power stored at the same sampling time are compared with each other, and the control information of the downlink transmission power corresponds to the amplitude fluctuation corresponding to the multipath fading. Control means for determining whether or not the vehicle is following the vehicle.

According to this configuration, it is possible to confirm whether or not downlink transmission power control for the mobile station device is normally performed in a multipath fading environment. That is, if the above is followed, the downlink transmission power control is performed normally.

A pseudo mobile station apparatus according to the present invention determines gain control means for uplink transmission power based on a downlink signal from a base station apparatus, and uses the uplink transmission power control information to control uplink transmission power. Generating means for generating an amplitude variation corresponding to fading of a radio propagation path, and a multiplication means for multiplying an uplink transmission signal whose power is controlled by the gain control means by an amplitude variation corresponding to the fading,
Is adopted.

According to this configuration, it is possible to artificially add an amplitude change corresponding to fading to the uplink transmission signal transmitted to the base station apparatus.

According to the transmission power control performance test method of the present invention, downlink transmission power control information is determined from an uplink signal from a mobile station apparatus, and downlink transmission power is controlled using the downlink transmission power control information. The downlink transmission signal to be controlled is generated and multiplied by an amplitude variation corresponding to fading of a radio propagation path, and the amplitude variation corresponding to the fading and the control information of the downlink transmission power are associated with each other at the same sampling time. The stored amplitude fluctuations corresponding to the fading and the control information of the downlink transmission power are compared at each of the same sampling times, and the control information of the downlink transmission power follows the amplitude fluctuations corresponding to the fading. It is determined whether or not there is.

According to this method, it is possible to confirm whether or not downlink transmission power control for the mobile station apparatus is normally performed in a fading environment. That is,
If the above is followed, it means that the downlink transmission power control is performed normally.

[0028]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a base station simulator according to an embodiment of the present invention.

The base station simulator shown in FIG. 1 includes a down converter 101, a demodulation unit 102, a channel codec unit 103, and an interface unit 10.
4, a modulation unit 105, an up-converter 106, a multiplication unit 107, a gain control unit 108, a two-dimensional Gaussian noise generation unit 109, a data storage unit 110, and a control unit 1.
11 are provided.

The down-converter 101 converts the frequency of an uplink RF signal (received signal) transmitted by a mobile station device (not shown) to be tested, and then converts it into a baseband signal.

The demodulation unit 102 includes a down converter 101
Is converted into a digital information data string after the despreading process. In demodulation section 102, transmission power control information 移動 TPC (Transmi
t Power Control) Extract bit｝. This control information is transmitted from the mobile station device on the uplink in order to keep the SIR (signal power to interference power ratio) constant in the mobile station device.

The channel codec unit 103 performs coding / decoding of error correction from the information data string from the demodulation unit 102 and disassembly / assembly of information data for conversion between a physical channel and a logical channel. .

The interface unit 104 converts information data from the channel codec unit 103 into services such as voice.

The modulator 105 spreads and multiplexes the downlink information data from the channel codec 103 to convert it into I and Q downlink baseband transmission signals to be transmitted to the mobile station apparatus. The modulation section 105 controls the transmission power for each physical channel.

Gain control section 108 outputs gain control information obtained after determining power for each physical channel from control information of transmission power of the mobile station apparatus, to modulation section 105 and data storage section 110.

The two-dimensional Gaussian noise generator 109 calculates I,
A Q-channel independent Gaussian noise signal source, a band-limiting filter corresponding to the maximum Doppler frequency of fading, and the like are used to generate a two-dimensional Gaussian noise signal indicating gain and phase fluctuation (amplitude fluctuation) due to fading. The data is generated and output to the multiplication unit 107 and the data storage unit 110.

The multiplication unit 107 is a complex multiplier, and multiplies the I and Q two-dimensional Gaussian noise signals from the two-dimensional Gaussian noise generation unit 109 by the I and Q downlink baseband transmission signals from the modulation unit 105. By doing so, the effect of fading (amplitude fluctuation of the fading propagation path) is added to the transmission signal.

The data storage device 110 stores both the two-dimensional Gaussian noise signal from the two-dimensional Gaussian noise generator 109 and the gain control information from the gain controller 108 in correspondence with each same sampling time. It is.

The control unit 111 processes data of a control channel for communicating with the mobile station device, controls each unit to perform a control sequence conforming to the standard of the communication system, and
It performs arithmetic processing and display processing of the data stored in the data storage unit 110.

The up-converter 106 includes a multiplication unit 107
Frequency conversion of I and Q downlink baseband transmission signals from the I and Q downlink RF signals (transmission signals)
Is output.

The operation of the base station simulator configured as described above will be described with reference to FIG.

FIG. 2 shows an amplitude fluctuation waveform 2 due to fading.
7 shows a mutual relationship between the gain control waveform 01 and a gain control waveform 202 by downlink transmission power control.

The control unit 111 obtains an amplitude fluctuation waveform 201 by performing a square root operation after summing the squares of the I and Q two-dimensional Gaussian noise signals stored in the data storage unit 110. A graph is displayed on display means (not shown) as shown in FIG.

The control unit 111 includes a data storage unit 11
0 from the gain control information stored at 0
2 is obtained and displayed on the display means in association with the amplitude fluctuation waveform 201 as shown in FIG.

Both of the displayed waveforms 201, 20
By comparing the two, it is possible to confirm whether or not downlink transmission power control for the mobile station apparatus is normally performed in a fading environment.

That is, if the gain control waveform 202 follows the amplitude fluctuation waveform 201, it means that the downlink transmission power control is performed normally. In other words, it means that the uplink transmission power control of the mobile station device is performed normally.

The maximum Doppler frequency is changed by changing the characteristics of the filter forming the two-dimensional Gaussian noise signal, and the function of transmission power control in a high-speed to low-speed mobile station apparatus can be confirmed.

As described above, according to the base station simulator of the embodiment, gain control section 108 determines the downlink transmission power control information from the uplink signal from the mobile station apparatus, and determines the downlink transmission power control information. Is used to control the downlink transmission power, a two-dimensional Gaussian noise generation unit 109 generates an amplitude variation corresponding to fading of a radio propagation path, and a multiplication unit 107 controls power according to downlink transmission power control information. The downlink transmission signal is multiplied by amplitude fluctuation corresponding to fading. Then, the amplitude fluctuation corresponding to fading and the control information of the downlink transmission power are stored in the data storage unit 110 in association with each other at the same sampling time, and the amplitude fluctuation corresponding to the stored fading is stored by the control unit 111. The control information of the downlink transmission power is compared with the control information of the downlink transmission power at the same sampling time, and it is determined whether the control information of the downlink transmission power follows the amplitude fluctuation corresponding to fading.

Thus, it is possible to confirm whether or not downlink transmission power control for the mobile station apparatus in a fading environment is normally performed.

FIG. 3 shows a state of confirming the transmission power control using the conventional and base station simulator apparatuses according to the present embodiment. As is apparent from FIG. 3, the base station simulator according to the present embodiment can confirm that downlink transmission power control is normally performed on the mobile station even in a fading environment. An excellent effect can be obtained in that the transient characteristics can be analyzed and confirmed, as compared with a method in which the reception level is varied by the attenuator and the variation in the transmission power is confirmed.

As shown in FIG. 4, when the fading pattern is fixed in the two-dimensional Gaussian noise generator 109 using the storage element 401 and is read out by the data readout circuit 402, random two-dimensional Gaussian noise is generated. An arbitrary pattern fading can be determined as compared with the case where a signal is generated. This makes it possible to compare and confirm the characteristics of the transmission power control for each mobile station device under the same conditions.

As shown in FIG. 5, it is possible to determine that the response of the gain control information (gain control waveform 202) to the level change due to the fading of the fixed pattern falls within the amplitude ranges 501 and 502 set by the examiner. By providing the function in the control unit 111, it is possible to easily select non-defective / defective products in a manufacturing process or a service of a mobile station device such as a mobile phone.

In the above description, the case of a single path is assumed, but in the case of a multipath, a base station simulator is configured as shown in FIG. That is, as shown in FIG. 6, a two-dimensional Gaussian noise generator 601 having a number of two-dimensional Gaussian noise generators corresponding to the number of multipaths,
Each of the two-dimensional Gaussian noise generator 201
And a multiplication unit 602 having multiplication means for multiplying the two-dimensional Gaussian noise signal from the two-dimensional Gaussian noise generation unit. Further, a delay element unit 603 composed of each delay element that performs signal delay corresponding to the delay of each path may be connected to a stage subsequent to the multiplication unit 602.

As a result, it is possible to confirm whether or not the downlink transmission power control for the mobile station device in a multipath fading environment is normally performed.

Further, the mobile station device determines a control information of the uplink transmission power from the downlink signal from the base station device, and uses the control information of the uplink transmission power to control the uplink transmission power; A two-dimensional Gaussian noise generation unit that generates an amplitude variation corresponding to fading of a propagation path, and a multiplication unit that multiplies an uplink transmission signal whose power is controlled by a gain control unit by an amplitude variation corresponding to fading. Good.

In this case, in the mobile station apparatus, an amplitude change corresponding to fading can be pseudo-added to the uplink transmission signal transmitted to the base station apparatus.

[0058]

As described above, according to the present invention,
In a state close to a fading environment in an actual radio propagation path, the performance of closed-loop downlink transmission power control for a mobile station device can be confirmed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a base station simulator according to an embodiment of the present invention.

FIG. 2 is a correlation diagram between an amplitude fluctuation waveform due to fading and a gain control waveform due to downlink transmission power control in the base station simulator according to the above embodiment.

FIG. 3 is an explanatory diagram of an effect of the base station simulator apparatus according to the embodiment.

FIG. 4 is a connection configuration diagram of a storage element and a data read circuit provided in a two-dimensional Gaussian noise generation unit of the base station simulator device according to the above embodiment.

FIG. 5 is an amplitude range instruction diagram for confirming normality between an amplitude fluctuation waveform due to fading and a gain control waveform due to downlink transmission power control in the base station simulator apparatus according to the above embodiment.

FIG. 6 is a block diagram showing a configuration example for multipath fading of the base station simulator according to the embodiment.

FIG. 7 is a block diagram showing a configuration of a mobile communication system using a conventional base station simulator device.

FIG. 8 is a block diagram showing a configuration of a conventional base station simulator device.

[Explanation of symbols]

 Reference Signs List 101 down converter 102 demodulation unit 103 channel codec unit 104 interface unit 105 modulation unit 106 up converter 107, 602 multiplication unit 108 gain control unit 109, 601 two-dimensional Gaussian noise generation unit 110 data storage unit 111 control unit 201 amplitude fluctuation waveform due to fading 202 Gain control waveform 401 Storage element 402 Data read circuit 501, 502 Amplitude range 603 Delay element section

Claims (7)

[Claims] 1. A gain control means for determining downlink transmission power control information from an uplink signal from a mobile station apparatus, and controlling downlink transmission power using the downlink transmission power control information. A base station comprising: a generating unit that generates a corresponding amplitude fluctuation; and a multiplying unit that multiplies a downlink transmission signal whose power is controlled by the gain control unit by an amplitude fluctuation corresponding to the fading. Simulator device. 2. A storage means for storing an amplitude fluctuation corresponding to fading and control information of downlink transmission power in correspondence with each same sampling time, and an amplitude fluctuation corresponding to the fading stored in this means. Compare the control information of the downlink transmission power for each of the same sampling time,
2. The base station simulator according to claim 1, further comprising: a control unit configured to determine whether control information of the downlink transmission power follows amplitude fluctuation corresponding to the fading. 3. The method according to claim 1, wherein said generating means stores a pattern of amplitude fluctuation corresponding to fading, and generates an amplitude fluctuation corresponding to fading of the stored pattern. Base station simulator device. 4. A gain control means for determining downlink transmission power control information from an uplink signal from a mobile station apparatus and controlling downlink transmission power using the downlink transmission power control information, a multipath of a radio propagation path. Generating means for generating amplitude fluctuation corresponding to fading; multiplying means for multiplying a downlink transmission signal whose power is controlled by the gain control means with amplitude fluctuation corresponding to the multipath fading; A delay unit for delaying a signal by a delay time for each path in a multipath. 5. A storage means for storing amplitude fluctuation corresponding to multipath fading and control information of downlink transmission power in correspondence with each same sampling time, and corresponds to the multipath fading stored in this means. Control means for comparing the amplitude fluctuation and the control information of the downlink transmission power at each of the same sampling times, and determining whether or not the control information of the downlink transmission power follows the amplitude fluctuation corresponding to the multipath fading. The base station simulator according to claim 4, comprising: 6. A gain control means for determining control information of uplink transmission power from a downlink signal from a base station apparatus and controlling uplink transmission power using the control information of uplink transmission power; Pseudo movement, comprising: a generating unit that generates a corresponding amplitude fluctuation; and a multiplying unit that multiplies an uplink transmission signal whose power is controlled by the gain control unit by an amplitude fluctuation corresponding to the fading. Station equipment. 7. The downlink transmission power control information is determined from an uplink signal from a mobile station apparatus, and downlink transmission power is controlled using the downlink transmission power control information. Generate and multiply an amplitude variation corresponding to the fading of the propagation path, store the amplitude variation corresponding to the fading and the control information of the downlink transmission power in correspondence with each same sampling time, and store the fading in the stored fading. Comparing the corresponding amplitude fluctuation and the control information of the downlink transmission power at each of the same sampling times, and determining whether the control information of the downlink transmission power follows the amplitude fluctuation corresponding to the fading. Transmission power control performance test method.