CN102595447A - Method and device for wireless measuring sensitivity of base station - Google Patents

Abstract

The invention discloses a method and a device for wireless measuring a sensitivity of a base station. The invention has the technical points of detecting the information channel of a detected base station; on one information channel of the list, changing the transmitting power of a test terminal 1 through a power regulator and counting the error rate on a test terminal 2; obtaining the received power of the base station corresponding to the test terminal to be used as the sensitivity of the base station on the information channel by using the corresponding transmitting power of the test terminal 1 under a setting error rate and the transmission performance of the wireless channel. According to the measure to the sensitivity of the base station realized by adopting the wireless way, the defect of the cable connection measuring sensitivity is effectively solved, for example, the base station antenna erected on a high mountain is difficult to connect through the incoming of wired lines, meanwhile, the normal operation of the base station cannot be affected by the measuring method provided by the invention, therefore, the method and the device have wide application prospect in the market.

Description

A method and device for wirelessly measuring base station sensitivity

technical field

The invention relates to the technical field of communications, in particular to a method and device for measuring sensitivity of a base station in a wireless channel. the

Background technique

In wireless communication systems, the performance of base station receivers is crucial. The sensitivity is an important index to measure the performance of the base station receiver. It reflects the ability of the base station receiver to receive weak signals. Base station sensitivity can not only affect the quality of the network, but also affect the coverage and capacity of the network. The measurement of base station sensitivity is very important.

The existing base station receiving sensitivity test system is measured in a wired way. Figure 1 schematically shows an example of measuring base station sensitivity in this wired way, the first test terminal 11 is connected to the high-frequency radio output end of the base station 5 through a directional coupler 13 and a cable, wherein the base station 5 includes a duplexer 6 , the transmitting part 7, and the receiving part 8. The radio signal output from the first test terminal 1 is connected to a directional coupler 13 via a coupler 2 , and a first attenuator 12 . The radio signal output from the first test terminal 1 is also connected to a power measuring instrument via a coupler 2 and a second attenuator 12 . In this way, through the measurement of the power measuring instrument, the power value of the radio signal entering the base station through the directional coupler 13 can be indirectly calculated according to the coupling coefficient and the attenuation of the line. Under the power control of the base station, this signal power is the receiving sensitivity of the base station. the

For details of the above-mentioned base station receiving sensitivity test system, refer to the patent "Method for Measuring the Receive Sensitivity of a Base Station with Multiple Frequency Allocations" (Patent No.: 03121077.5) filed by MTI Co., Ltd. on March 24, 2003. This kind of test system has high precision, but it will affect the normal operation of the base station, and needs the cooperation of the power control of the base station, and the sensitivity value measured when the base station fails is unreliable.

Contents of the invention

The invention provides a method and device for measuring the sensitivity of a base station in a wireless channel. By adopting the invention, the test system does not affect the normal operation of the base station. At the same time, the test system does not need the power control of the base station, which can still obtain reliable sensitivity values in the case of a failure of the base station, and reflect the problems of the base station in time.

The technical scheme that the present invention adopts is: the method for measuring base station sensitivity on the wireless channel, and its realization step comprises:

Step 1: the first test terminal selects an available channel, and establishes a connection with the second test terminal on the channel;

Step 2: On the reverse link between the first test terminal and the base station to be tested, change the transmission power of the first test terminal through a power regulator;

推算出基站对应于第一测试终端的接收功率

，作为基站灵敏度。 Step 3: a standard signal is pre-stored on the second test terminal, the standard signal is the same as the signal transmitted by the first test terminal, the second test terminal receives the signal, and detects the bit error rate or frame error rate of the received signal according to the standard signal, Use the transmit power of the first test terminal corresponding to the bit error rate or frame error rate at a certain threshold

Deduce the received power of the base station corresponding to the first test terminal

, as the base station sensitivity.

，其中

为第一测试终端的天线增益、

为基站天线增益、

为无线信道损耗值。 Preferably, the base station corresponds to the received power of the first test terminal

,in

is the antenna gain of the first test terminal,

is the base station antenna gain,

is the wireless channel loss value.

； Preferably, the base station corresponds to the received power of the first test terminal 1

;

是基站接收天线在第一测试终端的发射天线方向上的增益，

，分别为基站与第一测试终端发射天线轴向在垂直方向和水平方向的夹角；

是第一测试终端的发射天线在基站接收天线方向上的增益，

，

分别为第一测试终端与基站发射天线轴向在垂直方向和水平方向的夹角；

是发射信号波长；

是第一测试终端的发射天线与基站接收天线的距离。 in

is the gain of the receiving antenna of the base station in the direction of the transmitting antenna of the first test terminal,

, Respectively, the angles between the base station and the axis of the transmitting antenna of the first test terminal in the vertical direction and the horizontal direction;

is the gain of the transmitting antenna of the first test terminal in the direction of the receiving antenna of the base station,

,

Respectively, the angles between the first test terminal and the axis of the base station transmitting antenna in the vertical direction and the horizontal direction;

is the emission signal wavelength;

is the distance between the transmitting antenna of the first test terminal and the receiving antenna of the base station.

Preferably, the bit error rate or frame error rate threshold is selected to be a prescribed value corresponding to a specific logical channel under static or multipath propagation conditions.

Preferably, the base station is a GSM base station, IS-95 base station, TD-SCDMA base station, CDMA2000 base station, WCDMA base station or LTE base station, and the first test terminal and the second test terminal send and receive signals under the corresponding system to measure the corresponding base station sensitivity.

Preferably, the signal output end of the first test terminal 1 is connected to the signal input end of the power distribution unit 2, and a signal output by the power distribution unit 2 enters the signal input end of the power conditioner, and the signal output end of the power conditioner is connected to the first The transmitting antenna 10 of the test terminal is connected; another signal output by the power distribution unit 2 enters the power measuring instrument 4 .

的测算方法为：根据功率分配单元的功率分配比例系数将功率测量仪4测出的功率值换算成信号进入所述功率调节器的功率值，第一测试终端1的发射功率为进入所述功率调节器的功率值减去所述功率调节器的功率调节量和器件插入损耗量（如馈线的损耗量）后的数值。 Preferably, the transmit power of the first test terminal 1

The calculation method is as follows: according to the power distribution ratio coefficient of the power distribution unit, the power value measured by the power measuring instrument 4 is converted into the power value of the signal entering the power conditioner, and the transmission power of the first test terminal 1 It is the value obtained by subtracting the power regulation value of the power regulator and the insertion loss of the device (such as the loss of the feeder) from the value of the power entering the power regulator.

The device for measuring base station sensitivity on a wireless channel includes a first test terminal 1 and a second test terminal 9; the first test terminal 1 and the second test terminal 9 are located within the communication range of the base station to be tested 5, and both pass through the base station to be tested 5 establish communication;

Wherein the signal output end of the first test terminal 1 is connected with the signal input end of the power distribution unit 2, the signal output of the power distribution unit 2 enters the signal input end of the power conditioner, and the signal output end of the power conditioner is connected with the first test terminal The transmitting antenna 10 of 1 is connected; the other signal output by the power distribution unit 2 enters the power measuring instrument 4;

A standard signal is pre-stored on the second test terminal 9, and the standard signal is the same as the signal transmitted by the first test terminal 1. The second test terminal 9 is used to receive the signal, and detect the bit error rate or the error rate of the received signal according to the standard signal. frame error rate.

Preferably, the first test terminal 1 also has a signal connection with the controller 11, and the controller 11 is used to control the first test terminal 11 to perform a test on a certain channel to be tested; the power regulator is a digitally controlled attenuation Device 3.

Preferably, the first test terminal 1 and the second test terminal 9 are integrated to form a duplex wireless communication module.

The method and device for measuring the sensitivity of the base station under the wireless channel provided by the invention can not affect the normal operation of the base station. At the same time, the test system does not need the power control of the base station, which can still obtain reliable sensitivity values in the case of a failure of the base station, and can reflect the problems of the base station in time. The invention effectively solves the shortage of wired measurement and has broad market application prospects.

Description of drawings

Fig. 1 schematically shows an example of a conventional test structure for measuring the receiving sensitivity of a base station.

FIG. 2 schematically shows an example of a block diagram of a communication system used in the present invention.

Fig. 3 schematically shows a structure for testing the receiving sensitivity of a base station according to an embodiment of the present invention.

The flow chart of Fig. 4 shows the process for measuring the receiving sensitivity of the base station according to an embodiment of the present invention.

Fig. 5 schematically shows the radiation pattern of the transmitting antenna and the receiving antenna.

Marks in the figure: 1 is the first test terminal, 2 is the power distribution unit, 3 is the digital control attenuator, 4 is the power measuring instrument, 5 is the base station, 6 is the duplexer of the base station, 7 is the transmitting part, 8 is the receiving part, 9 is the second test terminal, 10 is the first test terminal transmitting antenna, 11 is the controller, 12 is the first attenuator, 13 is the directional power distribution unit, 14 is the second test terminal receiving antenna, 15 is the base station antenna; 20 , 21 is the mobile station, 22 is the forward link signal sent by the base station 5, 23 is the reverse link signal sent by the mobile station 20, 24 is the reverse link signal sent by the mobile station 21.

Detailed ways:

Specific embodiments of the present invention are given below. Fig. 2 is a schematic diagram showing a communication system block diagram of a specific embodiment of the present invention. The base station 5 establishes communication with the mobile stations 20, 21 on uplink and downlink wireless channels.

The implementation steps of adopting the base station sensitivity measurement method in the present invention are:

1. The first test terminal 11 selects an available channel, and initiates a call to the second test terminal 9 on the channel;

2. On the reverse link between the first test terminal 11 and the base station to be tested, change the transmission power of the first test terminal 11 through a power regulator;

3. Detect the bit error rate on the second test terminal 9, use the transmit power of the first test terminal 11 corresponding to a certain threshold value of the bit error rate to derive the received power of the base station, as the sensitivity of the base station. Meanwhile, the first test terminal 11 does not participate in the power control of the base station, and uses a power regulator to change the transmit power of the terminal. Moreover, the selection of the bit error rate threshold may correspond to the specified value of a specific logical channel under static or multipath propagation conditions (when the bit error rate is greater than this value, normal communication is considered impossible).

可通过天线发射功率

、第一测试终端发射天线增益、基站接收天线增益

、无线路径传播损耗

得到： Generally speaking, in the wireless path propagation, the received power of the base station antenna

Can transmit power through the antenna

, the first test terminal transmit antenna gain , base station receiving antenna gain

, Wireless path propagation loss

get:

是特定误码率下的第一测试终端11的天线发射功率，

是第一测试终端11的发射天线增益，

是基站接收天线增益，

是基站和第一测试终端11的无线信道传输损耗，将测得的基站天线接收功率

作为基站的灵敏度。 In the present invention,

is the antenna transmission power of the first test terminal 11 under a specific bit error rate,

is the transmit antenna gain of the first test terminal 11,

is the base station receiving antenna gain,

is the wireless channel transmission loss of the base station and the first test terminal 11, the measured base station antenna received power

Sensitivity as base station.

Fig. 3 is a schematic diagram showing a circuit structure for testing the receiving sensitivity of a base station according to an embodiment of the present invention. The terminal does not participate in the power control of the base station, and measures the receiving sensitivity of the base station under static transmission conditions. The first test terminal 11 is connected to the transmitting antenna 10 of the first test terminal through the power distribution unit 2 and the power conditioner (specifically, a digitally controlled attenuator 3 ). At the same time, the first test terminal 11 is connected to the power measuring instrument 1 through the power distribution unit 2 . The controller 11 controls the first test terminal 11 to perform a test on a certain channel to be tested.

A standard signal is pre-stored on the second test terminal 9, and the standard signal is the same as the signal transmitted by the first test terminal 1. The second test terminal 9 is used to receive the signal, and detect the bit error rate or the error rate of the received signal according to the standard signal. frame error rate.

The test terminal establishes a conversation with the second test terminal 9 on the wireless channel. The transmission power of the first test terminal 1 reaching the antenna 10 can be adjusted through the digitally controlled attenuator 3 , and the transmission power can be indirectly calculated from the test results of the power measuring instrument. When the attenuation is increased, the bit error rate calculated on the second test terminal 9 will increase. When the bit error rate reaches 2%, the transmitting power of the first test terminal 1 at this time can be used to calculate the receiving power reaching the base station as the receiving sensitivity of the base station.

Another specific embodiment of the base station sensitivity measurement method in the present invention is:

The selection of local test points meets the requirements of far-field testing and the existence of a direct path. It is assumed that the three-dimensional geographical coordinates of the base station and the test point are known; the antenna pattern of the test point and the pattern of the base station antenna; the frequency of the transmitted signal. Figure 4.

Firstly, the first test terminal 1 scans the available channels of the base station under test (step S1 ), and selects a channel to establish a call through the controller for measurement (step S2 ).

： Then, the bit error rate is counted on the second test terminal 9 (step S4). When the bit error rate is less than 2%, the uplink power of the first test terminal 1 is further reduced through the digitally controlled attenuator (step S3 ), and the second test terminal 9 re-counts the bit error rate. Adjust the digitally controlled attenuator until the bit error rate is greater than 2%. Using the transmit power of the first test terminal 1 when the bit error rate is 2%, the received power of the base station corresponding to the first test terminal 1 is calculated (step S3). In the test scenario in the present embodiment, the received power of the antenna can be calculated according to the Friis (Friis) transmission formula in the free space line-of-sight propagation model

:

为误码率为2%时的第一测试终端1的天线发射功率，

是基站接收天线在第一测试终端1的发射天线方向上的增益，

是第一测试终端1的发射天线在基站接收天线方向上的增益，

是发射信号波长，

是第一测试终端1的发射天线与基站接收天线的距离（参看图5）。 in

Be the antenna transmission power of the first test terminal 1 when the bit error rate is 2%,

is the gain of the receiving antenna of the base station in the direction of the transmitting antenna of the first test terminal 1,

is the gain of the transmitting antenna of the first test terminal 1 in the direction of the receiving antenna of the base station,

is the emitted signal wavelength,

is the distance between the transmitting antenna of the first test terminal 1 and the receiving antenna of the base station (see FIG. 5 ).

，第一测试终端1三维坐标为

，并且基站和第一测试终端1的天线都采用半波偶极子天线，极化方式相同，不考虑天线电下倾和机械下倾，则 Suppose the three-dimensional coordinates of the base station are

, the three-dimensional coordinates of the first test terminal 1 are

, and the antennas of the base station and the first test terminal 1 both use half-wave dipole antennas with the same polarization mode, regardless of the electrical downtilt and mechanical downtilt of the antenna, then

in, ,

，馈线(连接天线10和数控衰减器3)引入的插入损耗因子为

，则在天线与馈线阻抗匹配，天线效率

下，基站天线接收功率： In the structure 20 shown in Figure 3, when the bit error rate is 2%, the signal power after passing through the digitally controlled attenuator 3 deduced by the power measuring instrument 4 according to the power distribution ratio coefficient of the power distribution unit 2 is

, the insertion loss factor introduced by the feeder (connecting the antenna 10 and the digitally controlled attenuator 3) is

, then the impedance matching between the antenna and the feeder, the antenna efficiency

, the received power of the base station antenna:

                                                    

即为基站的灵敏度。

is the sensitivity of the base station.

It should be noted that the power distribution ratio coefficient is the power ratio between port 1 and port 2 of the power distribution unit. In the present invention, the power distribution unit has a signal input port and two signal output ports, that is, port 1 and port 2 of the power distribution unit. The power measuring instrument 4 multiplies the received signal power by the power distribution proportional coefficient to obtain the signal power entering the digitally controlled attenuator 3 .

Above-mentioned test method and device can be used for the measurement of receiving sensitivity of GSM base station, IS-95 base station, TD-SCDMA base station, CDMA2000 base station, WCDMA base station LTE base station etc., the first test terminal 11 and the second test terminal 9 send and receive under the corresponding system signal to measure the sensitivity of the corresponding base station.

The invention is not limited to the specific embodiments described above. The present invention extends to any new feature or any new combination disclosed in this specification, and any new method or process step or any new combination disclosed.

Claims (10)

1. the method for measuring base station sensitivity on the wireless channel, its realization step comprises: Step 1: the first test terminal selects an available channel, and establishes a connection with the second test terminal on the channel; Step 2: On the reverse link between the first test terminal and the base station to be tested, change the transmission power of the first test terminal through a power regulator; Step 3: a standard signal is pre-stored on the second test terminal, the standard signal is the same as the signal transmitted by the first test terminal, the second test terminal receives the signal, and detects the bit error rate or frame error rate of the received signal according to the standard signal, Use the transmit power of the first test terminal corresponding to the bit error rate or frame error rate at a certain threshold

Deduce the received power of the base station corresponding to the first test terminal

, as the base station sensitivity. 2. The method according to claim 1, wherein the base station corresponds to the received power of the first test terminal

,in is the antenna gain of the first test terminal,

is the base station antenna gain, is the wireless channel loss value. 3. The method according to claim 1, characterized in that the base station corresponds to the received power of the first test terminal (1)

; in

is the gain of the receiving antenna of the base station in the direction of the transmitting antenna of the first test terminal, , Respectively, the angles between the base station and the axis of the transmitting antenna of the first test terminal in the vertical direction and the horizontal direction;

is the gain of the transmitting antenna of the first test terminal in the direction of the receiving antenna of the base station,

,

Respectively, the angles between the first test terminal and the axis of the base station transmitting antenna in the vertical direction and the horizontal direction;

is the emission signal wavelength;

is the distance between the transmitting antenna of the first test terminal and the receiving antenna of the base station. 4. The method according to claim 1, 2 or 3, characterized in that the selection of the bit error rate or frame error rate threshold is a prescribed value corresponding to a specific logical channel under static or multipath propagation conditions. 5. method according to claim 4, it is characterized in that, described base station is GSM base station, IS-95 base station, TD-SCDMA base station, CDMA2000 base station, WCDMA base station or and LTE base station, the first test terminal and the second test The terminal sends and receives signals under the corresponding system to measure the sensitivity of the corresponding base station. 6. The method according to claim 5, characterized in that, the signal output end of the first test terminal (1) is connected to the signal input end of the power distribution unit (2), and a signal output by the power distribution unit (2) enters The signal input end of the power conditioner and the signal output end of the power conditioner are connected to the transmitting antenna (10) of the first test terminal; another signal output by the power distribution unit (2) enters the power measuring instrument (4). 7. The method according to claim 6, characterized in that the transmit power of the first test terminal (1)

The calculation method is as follows: according to the power distribution ratio coefficient of the power distribution unit, the power value measured by the power measuring instrument (4) is converted into the power value of the signal entering the power conditioner, and the transmission power of the first test terminal (1)

It is the value obtained by subtracting the power regulation value of the power regulator and the insertion loss of the device from the value of the power entering the power regulator. 8. The device for measuring base station sensitivity on a wireless channel, characterized in that it includes a first test terminal (1) and a second test terminal (9); the first test terminal (1) and the second test terminal (9) are located at the Within the communication range of the base station (5), both establish communication through the base station to be tested (5); The signal output terminal of the first test terminal (1) is connected to the signal input terminal of the power distribution unit (2), and a signal output by the power distribution unit (2) enters the signal input terminal of the power conditioner, and the signal output of the power conditioner The terminal is connected to the transmitting antenna (10) of the first test terminal (1); another signal output by the power distribution unit (2) enters the power measuring instrument (4); A standard signal is pre-stored on the second test terminal (9), the standard signal is the same as the signal transmitted by the first test terminal (1), the second test terminal (9) is used to receive the signal, and detects and receives the signal according to the standard signal The bit error rate or frame error rate of the signal. 9. The device for measuring base station sensitivity on a wireless channel according to claim 8, characterized in that, the first test terminal (1) also has a signal connection with the controller (11), and the controller (11) uses Controlling the first test terminal (11) to perform a test on a certain channel to be tested; the power regulator is a digitally controlled attenuator (3). 10. The device for measuring base station sensitivity on a wireless channel according to claim 9, characterized in that the first test terminal (1) and the second test terminal (9) are integrated together to form a duplex wireless communication module.

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