TWI223510B - System and method for multi-path simulation - Google Patents

Abstract

The present invention provides a system and method for multi-path simulation that employs a shielded anechoic chamber to avoid external electromagnetic interference and other uncontrollable transmission paths generated in testing, and divides and adjusts a signal into multiple simulation signals to simulate the attenuation and delay generated in multi-path transmission of the signal. The shielded anechoic chamber includes a turntable, controlled by a control unit, for carrying a wireless communication device to be tested and for changing the reception azimuth of the device, thereby measuring the electric wave transceiving of the device.

Description

1223510 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to a multi-path (mul ti-path) simulation system and method ', particularly a shielded anechoic chamber using a shielded anechoic chamber to avoid external electromagnetic interference, and A multi-path simulation system and method for adjusting a signal distribution into multiple analog signals to simulate the attenuation and delay of this signal when it is transmitted on multiple paths. [Previous Technology] In recent years, with the rapid development of wireless communication technology, the application of mobile phones and wireless local area networks (WLANs) has become increasingly common. Compared with continuous line signal transmission with only a fixed transmission path, wireless signal transmission has a multi-path characteristic. The so-called multi-path means that when a wireless signal propagates in space ’, due to the characteristics of the space, such as walls, obstacles, etc., it will cause the signal to be reflected, so there are multiple radio wave transmission paths between the transmitting end and the receiving end. For the receiving end, these signals arriving from different paths have multi-path effects such as inter-symbol interference and fading due to phasedifference between each other, increasing the complexity of signal transmission. Degree and instability, and this multi-path effect is a phenomenon that exists in most real environments. However, for manufacturers of wireless communication equipment, such as telephone handsets, telephone base stations, wireless interface cards (network interface card), wireless bridges (access points), etc., traditionally they are more accurate in the near future. Master the test conditions in the 'environment' like an open space, come

Page 5 1223510 V. Description of the invention (2) The signal transmission of the proposed product is completely unable to provide a reliable test report for the product. Because in this kind of environment, it is usually difficult to avoid electromagnetic interference (EMI) from the outside and generate unnecessary reflection paths; and in actual test operations, it may also be limited by space characteristics and lack flexibility. Or although a channel emulator is used to simulate the actual environment, the cable emulator's cable mode test system excludes the antenna of the wireless communication device under test and cannot test important antenna diversity. ) Performance, and cannot provide a complete and fair test report for the product. Therefore, 'it is really urgent and convenient to simulate this multi-path characteristic' and then test the strain performance of its products under the actual use environment as an important basis for design and development. In view of this, the present invention proposes a multi-path simulation system and method, which can not only avoid external electromagnetic interference and generate redundant reflection paths, but also is not limited by the communication space in operation, so as to achieve the purpose of simulating and controlling the real radio wave space. . [Summary of the Invention] The main object of the present invention is to provide a multi-path simulation system, which includes a signal simulation unit, which can adjust a signal distribution to N analog signals, so as to simulate the signals generated when the N paths are transmitted. Attenuation and delay, where N is an integer greater than one. The simulation system also includes a shielded anechoic chamber, which contains n antennas, which are coupled to the signal simulation unit and are used to transmit the N analog signals.

1223510 V. Description of Invention (3). A second object of the present invention is to provide a multi-path simulation method, which at least includes generating a signal; adjusting and assigning this signal to N analog signals, in order to simulate the attenuation and Delay, where N is an integer greater than one; using N antennas to respectively transmit ^ analog signals, wherein the N antennas are located in an anechoic chamber; and using communication devices in the anechoic chamber to receive the N analog signals. The present invention uses an anechoic chamber to avoid electromagnetic waves from the outside world; disturbances and unwanted reflections are produced. The inner wall of the radio wave dark room consists of: inside: most of its energy is absorbed, and the reflected signal can be reduced. The transmission attenuation between the two channels and its analog signal is actually what the signal =. The transmission attenuation reaches a level equivalent to the transmission delay. 1 = bad size Limitations can be simulated more; II. 1 dark room described means, the present invention can achieve simulation straight ^; special round. With the purpose of the former, it is more possible to _ from this can produce, only "/ workshop and control this radio space

Various I green wide shell tests or S tests are performed in the quasi-real radio wave space of the line experiment 1 to obtain various near-inverted and non-inverted measurements. In addition, another object of the present invention is to evaluate the results. Diversity gain (diVersity gain) 仏 A single day to measure the switching of communication devices 飨 grip bucket #, /, this communication device has a neutral, "normal line r type, and is placed in-electric wave = line mode; b. Generation-test Redundant number 3. The communication device is set to single-day subtraction amplitude; d. This test signal is used; with: weekly signal attenuation-attenuation-σ Zhouzheng is N analog signals, using the mode on page 7 1223510 V. Description of the invention (4) = Attenuation and delay of this test signal when N paths are transmitted, where N is an integer greater than one; e • Using N located in radio waves = the N analog signals; f • The communication device receives this N analog signals; ^ IK receives one of the signal parameters and obtains a reference value; h. Passes the two radios to the antenna diversity mode and attenuates the test signal by the second attenuation i 田 ΐ 曾 Γ: the signal received by the device The parameter is equal to the reference value; and the difference between the attenuation amplitudes of the second diversity antenna is the antenna of the communication device. Your review committee can further understand the present invention, and will use the accompanying drawings to describe the present invention in detail. The implementation is as follows. Understanding and [Embodiment] This section will use specific examples to simulate the implementation of the system and method = clear multi-path, which is the measurement of the diversity gain of wireless communication devices. One application example of χ 'block diagram: Figure t, the preferred embodiment of the simulation system of a square-diameter wireless communication space (N ^ greater than = is used to simulate N road devices U, used to generate-signal; model Including:-the signal is generated to the machine blunt generating device 11, and this signal is distributed; 敕 Λ: Wuxin 'is coupled to simulate this signal in this N distribution ^ weekly is N analog signals, late; Generation of attenuation and extensions generated by the switch; and an anechoic chamber 14 and a generating device 11 to control the interference and excess reflection paths, and to isolate the electrical j from the external electromagnetic interference generated to the 14 internal unwanted reflections Effect Page 1223510 V. Description of the invention (5) is minimized. The signal simulation unit 12a includes:-an attenuation set 121 for generating an attenuation signal by using the signal ^ generated by the device 11;-the power is Power divider 122 is coupled to the attenuation device ΐ2ι, and this t = number is allocated to N sub-attenuation signals; N attenuators 123a are coupled to the power knife configuration state 122, which are used to attenuate the N sub-attenuations. The attenuation of the signal when the signal is transmitted on N paths; n delays = (delay llne) 124, which are coupled to N attenuators 123 & and are used to delay the delays generated by the N attenuation of 123a attenuated by each of the N path transmissions. In another embodiment, two analog-direct paths are selected from the N paths, and the reference path may be omitted: 2. When N is equal to 2, 'a phase shifter is added to the reference path: 'y'; U e, Γ) 乂 For the reference path when it is attenuated by the attenuator 1 2 3 a and then the output is “phase ί.” Phase adjustment is performed to simulate the signal transmission through the two paths; ι 图 可The V-control half-control unit 13 "is coupled to the attenuation device 121, and the attenuation unit 1 is a step attenuator. The attenuation range is adjusted by the step-by-step method, which is convenient for adjusting the signal to generate a medium signal. Wireless communication space transfer process ::: 成 = Subtract. The larger the constant attenuation range, the larger the signal transmission wheel is: giant ($-evening, the control unit 13a can also be coupled to 1'1 attenuator 23a degree 3. No), to control the N attenuators separately The attenuation amplitude of 1 23a is 1223510 V. Explanation of the invention (6) ------ The inside of the anechoic chamber 1 4 contains: n antennas 丨 4 1, each of which consumes N of the lu fl nucleus 1 2 a Li green changed 194, 丨, / eight W a iN delay lines 1 z 4 to transmit N analog signals respectively; and a communication device 42 to receive the N analog signals. Among these, the N antennas 1 to 24 are directional antennas, such as a horn antenna, to form an antenna array. The radio wave to 14 further includes a quiet zone 143 for placing the communication device 142. The quiet zone 143 is generated by the characteristics of the anechoic chamber 14. In this area, the signal transmitted by the antenna 141 is indirectly except for the part that the antenna 141 directly transmits to the communication device 142 (that is, the direct path without reflection). The reflected signal of the path is minimized. Therefore, if the flood-passing device 14 is placed in the silent area 1 43, a better simulation effect can be obtained. The anechoic chamber 14 further includes a turntable 144 that can carry the communication device 142 to change the azimuth of the signal received by the communication device 142. Since the change of this bit affects the signal receiving characteristics of the communication device 142, when using the analog system 10 a to test the communication device 1 4 2 to be tested, the receiving position can be adjusted by the turntable 1 4 4 to measure the communication device 丨42 Receiving characteristics in different directions, such as antenna diversity effect and radiation pattern. In addition, in order to obtain a better simulation effect for the simulation system 10a, the signal _ generating device 11 adopts a Golden Sample, which is a communication device 142, and its characteristics are far in line with the technical standards and specifications that the communication device 142 should follow. 'The resulting signal is of better quality and meets testing needs. In addition, a vector signal generator (vect〇r signal

1223510 V. Description of the invention (7) generator) If necessary, a power amplifier (power is used as the signal generating device 11) can generate more accurate and more diverse signals as required. Please refer to Figure 1A again, the control unit 丨 3 a is also coupled to the turntable 44 to control the rotation angle of the turntable 1 4 4. The control unit 3a is also coupled to the communication device 1 4 2 to obtain the characteristics of the signal received by the communication I 1 14 2. This Signal characteristics can include: signal strength, signal quality, frame error rate, and throughput. Through the control unit 13a, in addition to controllable, In addition to generating the signal and adjusting the attenuation range of the signal, the turntable 144 can also be controlled to measure the antenna diversity effect and radiation field shape in different directions, and obtain the characteristics of the received signal for subsequent analysis steps. Figure 1B It is a block diagram of another preferred embodiment of the multi-path simulation system of the present invention. Compared with FIG. 1A, the first multi-path simulation system 10b uses a subtractor 123b to combine the attenuation device 121 in FIG. 1A with attenuation The functions of 123a are merged. Therefore, in the signal analog unit i2b, the function Ϊ = ΐ is connected to the signal generating device 11 and the signals generated by it are divided into N sub-signals; N attenuators 123] 3 are coupled to the power distribution Cry 122, when attenuating this N sub-signals 'to simulate the signal on N roads: exclusive reduction, N delay' line (deiay Hne) i24 and 1j lightly connected to ν; ΐ: Do not use Delay the N sub-floods attenuated by the N attenuators 123b to simulate the ground generated during the transmission of each signal path. In this preferred embodiment, the delay on one of the hometown test paths can be omitted. Line 124. And when N is equal to 2, refer to

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V. Description of the invention (8)

A phase shifter is added to the path to reduce the phase difference of the sub-signals. It is used to adjust the reference path via the attenuator 1231) 'in order to simulate the transmission of signals on the two paths, and in the separate formula, the composition and description of the heavy path are better. The operation method of the operation room 1 4 includes a number of methods: 21 to 22, 22, 3, 3, a, and 1, 1 to 3, and 1 to 3, and 2 to reduce the cost. Regarding the control unit 13b, the control unit 13 shown in FIG. 1A is used. As for the radio wave dark operation ', it is the same as that in Fig. 1A. = How to use the aforementioned simulation system 10a to implement the present simulation method. Fig. 2 is an operation flowchart of the multi-path simulation embodiment of the present invention. As shown in Fig. 2, this method generates a signal by the device 11; the device 121 attenuates the signal, @ generates an attenuation signal, and · the distributor 1 22 distributes the attenuation signal into N sub-attenuations. ^ Attenuator 123a Attenuate the N sub-attenuation signals separately to simulate the attenuation of the signal when it is transmitted on N paths; Second, the N: delay line 124 delays the N sub-attenuation signals, respectively, and produces a delay of * :. When the signal is transmitted in N paths, the N analog signals are transmitted using N antennas 1 to 41 respectively, and the N analog signals are received using communication device 142. In step 27, it is also possible to control the rotation angle of the turntable 144 by means of the control unit ▲ to change the orientation of the communication device 1 4 2 receiving the signal.

1223510 V. Description of the invention (9) In this preferred embodiment, it is also possible to select _to test paths among N paths. In step 25, N-1 delay lines 1 24 are used to delay the reference paths. N-1 sub-attenuation signals on the rest of the path (ie, the sub-attenuation signals on the reference path are not delayed). And, when N is equal to 2, add a step between steps 2 ^ 5 and 26, using a phase shifter on the reference path, ^ pair 1 " on the second test position by 1 2 3 a The sub-attenuated signal after subtraction is phase-cycled to simulate the phase difference generated when the signal is transmitted on two paths. — In another preferred embodiment, the aforementioned simulation system is used to implement the multi-path simulation method of the present invention. The difference from the flow in Fig. 2 lies in steps 22 to 25, where step 22 is omitted; in step 23, the signal is divided into N sub-signals by the power splitter 122; in step 24, N is used Each attenuator 1 2 3b attenuates the N sub-signals; and in step 25, the N sub-signals are delayed by N delay lines 丨 24 to generate N analog signals. By using the multi-path simulation systems 10a and 10b of the present invention, various signals can be tested for receiving wireless signals. A method for measuring the diversity gain of a wireless communication device using the analog systems 10a and 10b will be discussed below. The communication device 142 in the simulation systems 10a and 10b here is a communication device having a switchable to a single antenna mode or an antenna diversity mode. Fig. 3 is a flow chart of using the multi-path simulation system of the present invention to measure antenna diversity gain. As shown in Figure 3, this flow includes the following steps: v 31 by control mode; element 1 3 a sets the communication device 1 4 2 to a single antenna mode

a々351 05. Description of the invention (10) 32 Makes the signal 33 34 Makes a test signal for the clothing 11; Uses the clothing reduction device 121 to measure this test. -彳 o J ^ 5 Tigers reduce the first reduction amplitude; the whole number is N; Er Wu 2a assigns the time-delayed test signals to each other to adjust the timing of each test signal to simulate the KN path transmission of this test signal 3 5 36 37 38

The attenuation and delay produced by the inch; f thousand months J uses N antennas 丨 4 1 to transmit the N analog signals ·, the communication device 142 receives the N analog signals 2, j is measured by the control unit 13a and the communication device 142 The received message is a reference value; $ the control unit 13a switches the communication device 42 to the antenna diversity mode 39 and attenuates the test signal by the second attenuation amplitude, so that the communication device = 2 receives the signal parameter equal to the reference And the calculation of the first and second attenuation by the control unit 1 3 a is the diversity gain of the communication unit 142. ^ Another] Adjusting the rotation angle of the turntable 144 with the L unit 13a can change the orientation of the signal received by the communication device 142. Repeat steps 3 1 to 3 9 for different orientations to learn the receiving direction of the communication device 1 4 2 Diversity gain results in! 1 f response 1 In addition, the aforementioned signal parameters can be information such as signal strength, Λ mouth muzzle, or data throughput. Figure 4 is a flow chart of measuring the antenna diversity gain using the multi-path simulation system of the present invention. In the analog system 丨 〇b, the adjustment method of its distribution type is different from the analog system 10a, but it does not affect the calculation of the diversity gain. As shown in Fig. 4, this flow includes the following steps: 41 The communication device 142 is set to a single antenna mode by the control unit 13b

Page 1223510 i. Description of invention (11); 42 Make the signal generating device 11 generate a test signal; 4 3 Use the signal simulation unit 1 2 b to adjust this test signal distribution to n analog saying $ 虎 'to simulate this Attenuation and delay of the test signal during N transmissions; 44 Use N antennas 1 4 1 to transmit the N analog signals; 4 5 Enable the communication device 1 4 2 to receive the N analog signals; 4 6 Borrow The control unit 1 3 b measures the number of signal meters received by the communication device 1 4 2 to obtain a reference value; & > 4 7 The control device 1 3 b switches the communication device 1 4 2 to the antenna diversity mode, and Repeat steps 4 2 to 4 6 so that the ® signal parameter received by the communication device 1 4 2 is equal to the reference value; and 48 to change steps 41 to 48 by the same degree of path difference. General modification, it is stated that the present invention patent should control the single-path to single-value, that is, variable communication, and the range of the system described by the strength of the number is not inconsistent with the implementation, I would like to ~ ~ "《开 开 q: 5¾ The analog signal in one antenna mode and antenna diversity mode is communication Built-in antenna 142 of diversity gain. The control unit 13b is used to adjust the rotation angle of the turntable 144. The azimuth of the signal received by the device 142 is repeated, and the steps are repeated to determine the influence of the azimuth of the reception on the diversity gain. And signal ^ inflammation, signal quality or data throughput and other information. The present invention is described in detail by using preferred embodiments, but is not limited thereto. Anyone who is familiar with this skill can use the artisan's thinking to protect the scope of the patent application. In summary, the specificity of the patent law has met the requirements of the Patent Law.

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Page 16 1223510 Brief description of the drawings [Simplified description of the drawings] Figure 1A is a block diagram of a preferred embodiment of the multi-path simulation system of the present invention. Fig. 1B is a block diagram of another preferred embodiment of the multi-path simulation system of the present invention. Fig. 2 is an operation flowchart of a preferred embodiment of the multi-path simulation method of the present invention. Fig. 3 is a flow chart for measuring the antenna diversity gain using the multi-path simulation system of the present invention. Fig. 4 is an operation flowchart of another embodiment for measuring antenna diversity gain using the multi-path simulation system of the present invention. Explanation of figure numbers of the drawings: 10a-multipath simulation system 10b-multipath simulation system 11-signal generating device 12a-signal analog unit 12b-signal analog unit 1 2 1 -attenuation device 1 2 2 -power divider 1 2 3 a-Subtractor 123b-Attenuator 1 2 4-Delay line 1 3 a-Control unit

Page 1223510 Schematic description 13b- Control unit 1 4-Anechoic chamber 1 4 1-Antenna 1 4 2-Communication device 143-Silent area 144-Turntable 2 1 ~ 2 7-Operation of the multi-path simulation method of the present invention Process 3b 39-Operation of measuring antenna diversity gain using the multipath simulation system of the present invention Flow 4b 48-Operation flow of another embodiment of measuring antenna diversity gain by the multipath simulation system of the present invention

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Claims (1)

1223510 VI. Scope of patent application1. A multi-path simulation system at least: a signal generating device for generating a signal; a signal simulation unit connected to the signal generating device, and adjusting the signal distribution to N analogs Signal to simulate the attenuation and delay of the signal when it is transmitted in N paths, where N is an integer greater than one; and a shielded anechoic chamber, which contains N antennas, which is coupled to the signal simulation Units for transmitting the N analog signals respectively. 2. The multi-path simulation system according to item 1 of the scope of patent application, wherein the signal simulation unit includes: a attenuation device for attenuating the signal to generate an attenuation signal; a power divider coupled to the attenuation device , The attenuation signal is divided into N sub-attenuation signals; N attenuators are coupled to the power divider, and are respectively used to attenuate the N sub-attenuation signals, so as to simulate the attenuation of the signals when they are transmitted in the N paths. ; And ^ 1 delay line ((1618λ1 丨 1 ^), respectively coupled to N-1 attenuator of the ^ attenuator, to delay ^ attenuated by the N-1 attenuator Attenuate the signal to simulate the delay of the signal when it is transmitted on the N-1 paths. 3. The multi-path simulation system as described in item 2 of the scope of patent application, where n equals 2, the two The attenuator is a first attenuator and a second attenuator. The knife is used to reduce the attenuation of a brother, a child, a farmer, and a second child. 1223510 VI. Patent Application Range No. The signal simulation unit further includes: a phase shifter coupled to the first attenuator to adjust the phase of the first sub-attenuation signal to simulate the signal The phase difference generated during the transmission of the two paths. 4. The multi-path simulation system according to item 2 of the scope of patent application, wherein the attenuation device is a step attenuator. 5 _ The multi-path simulation system as described in item 1 of the scope of patent application, wherein the signal simulation unit includes: 〃 / power distribution is coupled to the signal generating device, and the signal is divided into N sub-signals; N attenuation , Are coupled to the power splitter, and are respectively used to attenuate the N sub-flood numbers, in order to simulate the attenuation of the signal when the signal is transmitted on the n paths, and N-1 delay Une, respectively coupled To the N-1 attenuators of the N attenuators to delay the pi sub-signals attenuated by the N-i attenuators to simulate the delays respectively generated when the signals are transmitted on the N-1 paths. 6 · The multi-path simulation system as described in the item # of the patent scope. When n in 1 is equal to 2, the two attenuators are a first attenuator and a second attenuator. Attenuation ~ The _th sub-signal and a second sub-signal. The signal analog unit further includes: ^ hase shifter, coupled to the first attenuator to adjust the phase of the first sub-signal, In order to simulate the opposite cover generated when the signal is transmitted in the two paths. Page 20 1223510 6. Scope of patent application 7 · The multi-path simulation system as described in item 丨 of the scope of patent application, wherein the interior of the anechoic chamber further includes: a communication device for receiving the N analog signals. 8. The multi-path simulation system as described in item 7 of the scope of the patent application, wherein the interior of the anechoic chamber further includes: a turntable 'to carry the communication device and change the orientation of the communication device (azimuth). The multi-path simulation system described in item 7 of the patent scope, wherein the communication device is located in the Uinet zone of the anechoic chamber) 0 1 0 · If the application for a patent Ifl flute, evening j 1 4 # 围 弟 1 According to the above item, the heavy path simulation system, wherein the generation system using the Λ number is a vector signal to generate a cry. The multi-path simulation system described in item 7 above, wherein two or two. It is the selected sample of the communication device (Golden 12. — A multi-path simulation method, which contains at least. Generates a signal; assigns the §fL 5 tiger to the & path transmission ^ to N analog signals, and Simulate the attenuation and delay of the signal in the full inch of N.-, respectively. The exposure to N antennas is located in the -wave dark V. The N :: pseudo signal, "The N antennas use the radio dark Indoor_ 、 '士 1 3 · If the scope of the patent application, the signal device receives the N analog signals. The multi-path simulation method described in the item, on page 21 of I2235l0, please request a patent range m ~. The signal is using a The vector signal is generated as a result. 1 4 · The multipath simulation method as described in item 12 of the scope of patent application, wherein the signal is generated using one of the communication devices and selected samples. 1 5 · As the scope of patent application The multi-path simulation method described in item 12, wherein the signal miscellaneous adjustment adjustment includes: attenuating the signal to generate a decay signal; assigning the attenuation signal to N sub-attenuation signals' attenuating the N sub-attenuation signals To simulate the attenuation of the signal when it is transmitted on the N paths; and to delay the N sub-attenuation signals to simulate the delay of the signal when it is transmitted on the N paths. The multiple road control simulation method described in item 15, wherein when N is equal to 2, the attenuation signal will be allocated as a first sub-attenuation signal and a second sub-attenuation signal. The allocation adjustment steps of the signal further include: adjusting the The phase of the first sub-attenuation signal is used to simulate the phase difference that occurs when the signal is transmitted on the two paths. 1 7 · The multi-path simulation method described in item 15 of the patent application scope, wherein a step attenuator is used The signal is attenuated to generate the attenuated signal. # 1 8 · The multiple road control simulation method described in item 12 of the patent application scope, wherein the step of adjusting the allocation of the signal includes: · Allocating the signal into N sub-signals; Attenuate the N sub-signals to simulate when the signal is transmitted on the N paths Page 22 1223510 VI. Patent application scope separately generated attenuation; and delaying the N sub-signals to simulate the respective delays of the signal when transmitting on the N paths. 1 9. A method for measuring the diversity gain of a communication device, the communication device having a single antenna mode and an antenna diversity mode switchable, and placed in an anechoic chamber, the method includes the following steps: a. The communication device Set to the single antenna mode; b. Generate a test signal; c. Attenuate the test signal by a first attenuation amplitude; d. Adjust the test signal allocation to N analog signals to simulate the test signal on N paths The attenuation and delay generated during transmission, where N is an integer greater than one; e. Transmitting the N analog signals by using N antennas located in the anechoic chamber; f. Enabling the communication device to receive the N analog signals; g Measuring a signal parameter received by the communication device to obtain a reference value; h. Switching the communication device to the antenna diversity mode, and attenuating the test signal by a second attenuation range, so that the communication device receives The signal parameter is equal to the reference value; and i. Calculating the difference between the first and second attenuation amplitudes, which is the antenna diversity gain of the communication device. 2 0. A method for measuring the diversity gain of a communication device having a single antenna mode and an antenna diversity mode switchable, and Page 23 1223510 Placed in an anechoic chamber, the method includes the following +, a. Set the communication device to the single antenna mode b. Generate a test signal; 工, imitate No. 4 to simulate the attenuation and delay of the test The line transmits the N analog signals. C. Adjusts the test signal allocation to n mode test signals. When N paths are transmitted, N is an integer greater than one. D. N uses the sky in the anechoic chamber. E. Make the communication device to receive the n analog signals. F. Measure one of the signal parameters received by the communication device to get a test value. G. Switch the communication device to the antenna diversity mode and repeat the steps. b to f, so that the signal parameter received by the communication device is equal to the reference value; and h. one of the N paths is selected, and the selected path is different in the single antenna mode and the antenna diversity mode The difference between the analog signals is the antenna diversity gain of the communication device. 2 1 · The method described in item 19 or 20 of the scope of patent application 'In step b, the test signal is generated using a vector signal generator. 22. The method described in item 19 or 20 of the scope of patent application 'In step b, the test signal is generated using a selected sample of the communication device. 2 3 · According to the method described in item 19 of the scope of the patent application ^ In steps C and 11, the test signal is attenuated using a step attenuator. 24. The method according to item I9 or 20 of the scope of patent application ’, wherein the signal No. 24 Tribute 1223510 Page 25