WO2009039693A1

WO2009039693A1 - Testing method of the ota performances of a wireless communication product

Info

Publication number: WO2009039693A1
Application number: PCT/CN2007/003632
Authority: WO
Inventors: Lijuan Wang; Zhong Yu; Hongli Peng; Wei Xie
Original assignee: Zte Corporation
Priority date: 2007-09-24
Filing date: 2007-12-17
Publication date: 2009-04-02
Also published as: CN101399621A; CN101399621B

Abstract

The present invention discloses a testing method of the OTA performances. The method includes following approaches: the step of setting up a spherical coordinate system, the step of selecting the testing points, the step of testing, and the step of dealing with the data. By using the present invention, OTA testing points can be distributed on the spherical surface equably, and the number of testing points is reduced while satisfying the testing precision, so as to save the testing time and simplify the disposal arithmetic of the testing results.

Description

TECHNICAL FIELD The present invention relates to the field of radio frequency test techniques for wireless communication products, and in particular to a method for testing spatial radio frequency performance of a wireless communication product (Over The Air, OTA). BACKGROUND With the development of modern industry, all kinds of wireless communication products can only guarantee communication quality if they have good transmitting and receiving performance, that is, Total Radiated Power (hereinafter referred to as TRP) is higher than a certain value, The Total Isotropic Sensitivity (TIS) is required to be a certain value, that is, the spatial RF performance (Over The Air, hereinafter referred to as OTA).

CTIA (Cellular Communication Standardization Association) In order to ensure the normal use of mobile terminal equipment in the network, the test standard for mobile terminal space RF performance is defined as "The test plan for mobile station OTA performance". Currently, many operators require access to their networks. The radio frequency performance of the mobile terminal space shall be tested in accordance with the requirements of the CTIA standard, and the TRP and TIS shall meet certain limit requirements. In the CTIA standard, the measurement of TRP and TIS is performed on the spherical surface centered on the device under test. In order to accurately evaluate the transmitting and receiving performance of the device under test, it is necessary to select enough test points. The wireless communication product is placed on a first rotating shaft or a second rotating shaft of a testing device, the first rotating shaft rotating range is 0-180 degrees, and the second rotating shaft rotating range is 0-360 degrees. 15 degrees Θ (0-180 degrees) and Φ (0-360 degrees) take a test point, a total of 264 points need to be tested. TIS test needs to be every 30 degrees 0 (0-180 degrees) and Φ (0-360 degrees) Take a test point and test a total of 60 points. Since the test points are equally selected, they are non-uniformly distributed on the spherical surface. TRP, TIS need to calculate the ball area according to all test points. In the operation, for two test points located at θ=0, θ=180, the sine value is zero, so these two points are not tested. With the development of information technology, the space performance test of wireless communication products is more and more More and more complex, testing The occupied time is a bottleneck that restricts the test speed of the space RF performance test. With the increase of multi-band wireless communication products, the time to complete the evaluation of the spatial RF performance is also higher. Long, at present, for the existing spherical angle test method, the test point is in the spherical life -: uneven cloth, in order to more accurately evaluate the spatial RF performance of the EUT (Equipment Under Test) Need to measure enough points, TRP test 264 points, TIS test 60 points. The test speed of RF performance depends largely on the number of test points, so too many test points will cause the test time to be too long. In addition, in the processing of the test results, because the test points are non-uniformly distributed on the spherical surface, the calculation of TRP and TIS requires 4 spheres to be processed, and the calculation process is complicated. Furthermore, the two points on the spherical surface with angles of 0 degrees and 180 degrees are 0 in the calculation and do not work in the TRP or TIS calculation. In view of the above, if a calculation method capable of saving test time and simplifying the test can be provided, it is undoubtedly ideal for a spatial RF performance test method which is meaningful for the test results when Θ is equal to 0 degrees and 180 degrees. SUMMARY OF THE INVENTION The present invention has been made in view of the above problems in the related art, and an object of the present invention is to provide a spatial radio frequency performance testing scheme for a wireless communication product. According to the present invention, a spatial RF performance testing method is provided. The method includes: "Spherical coordinate system establishing step, and establishing the spherical coordinate defined by the x, y, and z axes with the measured wireless communication product as the coordinate origin. Θ The angle is the angle between the i-type point and the positive direction of the z-axis. , φ angle is the angle between the positive X-axis and the projection point of the test point on the x and y planes; the test point selection step, using the normal N-plane to triangulate the entire sphere to obtain the test as evenly distributed as possible on the sphere Point; where a vertex of the positive N-face is located at θ = 0 degrees. In the test path planning step, test path planning is required to increase the difficulty of mechanical implementation. Rotate the first rotation axis and the second rotation axis of the test device, per The angle of the corner corresponding to a test point is tested in a certain order. The points with the same angle are tested according to the φ size in a certain order. The data processing step is to linearly average the data measured at each test point to obtain the required TRP. And the TIS value, the formula is as follows:

N

ΕΙ8φ(θ φ where Ν is the number of measurement points obtained by triangulating L times, η is L times triangulation to obtain the number of test points with different Θ values, m is the same as the angle of the triangle obtained by triangulation of L times but φ The number of test points with different angles.

EiRP _g ( , is the equivalent omnidirectional radiated power horizontal polarization component value of the test point at angle έ>, , , in milliwatts.

) For the angle of , the equivalent omnidirectional radiated power of the test point is the value of the vertical polarization component' in milliwatts.

EIS _e (θ φ _Ί ) is the equivalent omnidirectional received power horizontal polarization component of the test point at an angle of _/ , in milliwatts.

EIS _e is the value of the equivalent omnidirectional received power vertical polarization component of the test point of angle Θ, φ., in milliwatts. In the above method, in the test step, the test system is not increased in mechanical complexity, and the first rotation axis and the second rotation axis of the rotation test device measure each test point. For test points with equal corners, the test points are measured in the order of φ angles. 3⁄4. By the invention, the distribution of the test points on the sphere can be made as uniform as possible, which can meet the requirements of test accuracy. In this case, the number of test points is reduced, thereby saving test time, while simplifying the test result processing algorithm, and the test results at 0 and 180 degrees are meaningful for the evaluation of spatial performance. Other features and advantages of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be apparent from the description, or will be apparent from the <RTIgt; The structure specifically indicated is implemented and obtained. The drawings are intended to provide a further understanding of the invention, and are intended to be a part of the description of the invention. In the drawings: FIG. 1 is a flow chart of a method for testing a spatial RF performance according to an embodiment of the present invention; FIG. 2 is a spherical coordinate system established with an origin of a wireless communication product under test; FIG. 3 is a two rotation axis of the test device; FIG. 4 is a schematic diagram of a normal icosahedral spherical surface treatment on a spherical surface according to an embodiment of the present invention; FIG. 5 is a schematic diagram of a regular icosahedral spherical surface triangulation; FIG. 6 is a three-dimensional triangulation using a regular icosahedron; The obtained test point distribution map; FIG. 7 is a test point distribution diagram obtained by performing two times of triangulation using a regular icosahedron; FIG. 8A is a schematic diagram of a test apparatus according to an embodiment of the present invention; FIG. 8B is a schematic diagram of a test apparatus according to an embodiment of the present invention; Another test device schematic diagram; Fig. 9 is a test point test path diagram obtained by using a regular icosahedron for three times of triangulation; Fig. 10 is a test point test path diagram obtained by using a regular icosahedron for two times of triangulation; A list of angular distributions of test points is planned twice in accordance with an embodiment of the present invention. Figure 12 is a list of angular distributions of planned test points for three times in accordance with an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) The following is a description of the preferred embodiments of the present invention, Firstly, a spatial RF performance measurement method for a wireless communication product is provided. As shown in FIG. 1, the method may generally include the following processes: a spherical coordinate system establishing step (S102), and a test point selecting step (S104) ), test step (S106), and data processing steps (S108). Each processing step will be further described in detail below.

(I) Spherical coordinate system establishment For the wireless RF performance test of wireless communication products, the spherical coordinate system defined by the x, y, and z axes is established with the measured wireless communication products as the origin. The Θ angle is the angle between the test point and the positive direction of the z-axis. The φ angle is the angle between the positive X-axis and the projection point of the test point on the x and y planes. See Figure 2. The measured wireless communication product is placed on a first rotating shaft or a second rotating shaft of a testing device, and the corresponding relationship between the two rotating shafts of the testing device and the space spherical coordinates is shown in Fig. 3;

(II) Test point selection Use the normal N-facet to triangulate the entire sphere to obtain the test of the uniform hook on the spherical surface.

The so-called triangulation means that the unit sphere is first divided into a regular tetrahedron, a regular octahedron, a regular dodecahedron, or a regular icosahedron. Each surface corresponds to a spherical triangle, and then the midpoint of the three sides of the spherical triangle is connected. A spherical triangle is divided into four spherical triangles, and the vertices of the triangular mesh are taken as test points. So recursively divide until the number of triangles required is the number of test points. The vertices of these triangles are distributed as evenly as possible over the entire sphere. Therefore, as long as sufficient test points are obtained, the spatial RF performance total transmit power (TRP) and omnidirectional receive sensitivity (TIS) of the mobile terminal or other wireless devices can be evaluated. Because the test points are evenly distributed on the sphere, the number of test points required for TRP and TIS tests can be greatly reduced, thus reducing test time. For example, on the spherical surface as shown in Figure 2, select the test point by the following process: First, positive

The icosahedron triangulates the entire sphere, and the purpose of the spherical triangulation is to evenly distribute the test points on the sphere. When the sphere is evenly triangulated, the unit sphere may be first divided into a regular tetrahedron or a regular octahedron, or a regular dodecahedron, a regular hexahedron or an icosahedron. Here, taking the regular 20-faced body as an example, the description is shown in Fig. 4 and Fig. 5. In Fig. 4, 1 and 12 are spherical vertices, 2-11 are respectively two regular pentagon vertices, and points 2 to X are respectively The positive angle is 26.565 degrees; in Figure 5, the triangles 1-2-3 are respectively triangle 4 1 1 -4-6, 4-2-5, 6-5-3, 4-5-6 The triangle, in turn, class 4 is divided to obtain the required number of measurement points, and the test points are selected at the vertices of each spherical triangle. In Fig. 6, 1 is the test point, and 2 is the triangle after triangulation. Each face corresponds to a spherical triangle, and then connects the midpoint of the three sides of the spherical triangle. Each of the spherical triangles is divided into four spherical triangles, so recursively divided until the required number of triangles is reached. Test points are selected at the vertices of each spherical triangle. Figure 6 shows the distribution of test points obtained by performing triangulation three times. 162 test points can be obtained. These test points are distributed as evenly as possible on the spherical surface with the device under test as the midpoint. The measurement of the point can accurately give the same TRP value as the method on CTIA. It can accurately evaluate the spatial RF performance TRP of the device under test, but the test point is reduced from 264 points specified by the CTIA standard to 162 points, thus reducing the measurement time by about 38%. For the TIS test, only two rounds of triangulation are required, and 42 points are measured. As shown in Fig. 7, the receiving performance of the test equipment can be fully evaluated. The measured result is the same as the TIS result obtained by the CTIA test method, and every 30 times specified by the CTIA. The degree angle test reduces the number of points by 18 points, which reduces the measurement time by 30%. At the same time, since the test points are evenly distributed on the spherical surface, the integral processing of the test results in the CTIA standard is avoided, and only the measurement results are linearly averaged, which simplifies the test result processing algorithm, thereby saving the result processing time. Since the results of the previous processing of the test are used, the measurement results for Θ equal to 0 and 180 degrees cannot be covered in the evaluation of the entire test result, but this is avoided by linear averaging.

(3) Test step 43⁄4 Referring to Figs. 8A and 8B, Fig. 8A is a test device, 1 is a first rotating shaft, the shaft rotation range is 0-180 degrees, 2 is a second rotating shaft, and the rotation range is 0- 360 degrees, 3 is the measuring antenna. Fig. 8B is another test device, 1 is a first rotating shaft, the shaft rotation range is 0-180 degrees, 2 is a second rotating shaft, and the rotation range is 0-360 degrees. 3 is the measuring antenna. In order not to increase the mechanical difficulty of the test device, each test point is measured by sequentially rotating the test device rotation axis Θ axis Φ axis. After obtaining the test points on the spherical surface, the path planning of the test is required. After analyzing the angle values corresponding to the test points, a number of points with different φ angles are corresponding on the same corner. The closer to the big circle, the more points that need to be measured, and the fewer test points required near the poles, thus avoiding the equal angle test method in the CTIA standard that needs to measure the same number of points on any one of the height angles. To do this, test the test points corresponding to different φ ( 0-360 ) on the plane corresponding to each corner according to the order of the Θ ( 0-180 ) of the test points; Each test point is tested in the order of magnitude of φ. Among them, Figure 9 shows the TRP test points and path planning, and Figure 10 shows the TIS test points and path planning. First, rotate both axes of the test device to 0 degrees to make the state of the device under test meet the test requirements. Start the test from the point of θ = 0 degrees, after the test is completed Rotating the first axis of rotation of the test device to the next angle, corresponding to several angles of different values of φ, rotating the second axis of rotation of the test device, testing the points in turn, and so on. Point. The test points of the 2nd division and the 3rd division are shown in FIG. 11 and FIG.

(IV) Data Processing The spatial RF performance indicators TRP and TIS of mobile terminal equipment or other wireless communication products can be obtained by linearly averaging the data measured at each test point. It does not require complicated integration operations, which simplifies the calculation method. Through the invention, the distribution of the test points on the space on the spherical surface can be made as uniform as possible, and the number of test points can be reduced under the condition of satisfying the test accuracy and the accuracy requirement, thereby saving test time. The above description is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the scope of the present invention are intended to be included within the scope of the present invention.

Claims

Claim

A spatial RF performance test method for spatial RF performance testing of a wireless communication product, wherein the measured wireless communication product is placed on a first rotating shaft or a second rotating shaft of a testing device, wherein the method comprises :

a spherical coordinate system establishing step of establishing a spherical coordinate system defined by the x, y, and z axes with the measured wireless communication product as an origin;

The test point selection step is to use the normal N-facet to triangulate the entire sphere to obtain a test point uniformly distributed on the spherical surface;

a test step of rotating the first rotating shaft and the second rotating shaft of the testing device, and sequentially testing the spatial RF performance data of the test points corresponding to different φ angles on the plane corresponding to each corner according to the corner angle of each test point Wherein the corner is the angle between the test point and the positive direction of the x-axis, and the angle φ is the angle between the forward direction of the X-axis and the projection point of the test point on the x, y plane;

In the data processing step, the spatial RF performance data measured at each test point is linearly averaged to obtain the total test result.

2. The method according to claim 1, wherein in the testing step, for test points having the same angle, each test point is tested in order of magnitude of φ.

The method according to claim 2, wherein the testing step comprises: sorting according to the size of the Θ value corresponding to the test point, and the test point having the same Θ value but different φ values according to the φ value Sorting, testing the spatial RF performance data of each test point in the order of the sorted test points.

The method according to claim 1, wherein the first rotating shaft has a rotation range of 0-180 degrees, and the second rotating shaft has a rotation range of 0-360 degrees.

The method according to claim 1, wherein the test point selecting step specifically divides the spherical surface into a regular tetrahedron, a positive ^\ plane, a dodecahedron, or an icosahedron, each surface Corresponding to a spherical triangle, connecting the midpoints of the three sides of the spherical triangle, ■! Each spherical triangle of the bar is divided into four spherical triangles, and the vertices of the triangular mesh are taken as test points.

The method according to claim 1, wherein the spatial radio frequency performance data of each test point comprises at least one of the following data: transmit power, receive sensitivity.

7. The method according to claim 6, wherein the step of calculating the total test result according to the data processing step is: .. -.. Calculating the total transmit power (TRP) according to the following formula:

TRP ≡^-∑∑ [EiRP _e (θ _ι , φ _ί ) + EiRP* (θ, , _} ) and/or calculate the omnidirectional receiving sensitivity (TIS) according to the following formula:

Wherein, for the number of measurement points obtained by tri-degree triangulation, η is the L-th-triangulation to obtain the number of test points with different Θ values, and m is the same as the Θ angle obtained by the L-th-triangulation. Count the number;

& ^ ( , ^ ) is the equivalent omnidirectional radiated power horizontal polarization component value of the test point of angle ^, in milliwatts;

EiRP^ (θ _ί ,φ _ί ) is the value of the equivalent omnidirectional radiated power vertical polarization component of the test point with angle θ( , φ _} , in milliwatts; for the angle, the equivalent of the test point of ^ The value of the polarization component to the received power level, in milliwatts;

EIS _e (θ _ί , ) is the equivalent omnidirectional received power vertical polarization component of the test point with angles θ , φ _ί , in milliwatts.