CN102158242B - System and method for testing antijamming capability of wireless communication products operating at ISM (Industry, Science and Medical) frequency range - Google Patents

Abstract

The invention provides a system and method for testing antijamming capability of wireless communication products operating at ISM (Industry, Science and Medical) frequency range, which relates to the method and the method for testing antijamming capability of wireless communication products and solves the problem that the antijamming capability of wireless communication products operating at ISM frequency range can not be tested. The system works as follows: signals transmitted by a transmitter are input into a receiver after passing through a first adjustable attenuator and a first combiner; signals transmitted by a signal source are input into the receiver after passing through a second adjustable attenuator and a second combiner. The method comprises the steps of: simulating signals of common radio communication systems near and in communication product working frequency bands through a signal source; and observing error code conditions of a receiver to be tested by adopting receiver error coder characteristic testing equipment to obtain a desired signal power and an interference signal power of each system and further realize quantitative analysis on the antijamming capability of the wireless communication products operating at ISM frequency range. The invention is applicable to testing the antijamming capability of the wireless communication products operating at ISM frequency range.

Description

System and test method for testing anti-interference ability of ISM frequency band wireless communication products

technical field

The invention relates to a system and a testing method for testing the anti-interference ability of wireless communication products.

Background technique

In order to reduce the mutual interference between different radio communication systems, the International Telecommunication Union has allocated corresponding frequency bands for each wireless communication system, and stipulated the power range of the transmitter and the spectrum template of the transmitted signal. However, the ISM frequency band is an exception. Since there is no authorization restriction, this frequency band is used by many short-distance communication products, so the mutual interference between these products and the interference of other frequency band radio communications to these products have become problems that cannot be ignored. The meaning of the mentioned ISM frequency band is the same in all countries, namely: 2.4GHz frequency band.

A wireless communication receiver actually working in the ISM frequency band is in an open electromagnetic environment, and wireless signals of other common radio communication systems will interfere with the receiver. It is very difficult to test these interference signals in the actual environment. On the one hand, some signals are sudden and difficult to capture with instruments; How much interference each signal alone causes to the receiver.

Agilent provides corresponding test instruments for Wi-Fi, Bluetooth and ZigBee currently working in the ISM frequency band. These instruments can measure every indicator of each product transmitter and receiver, but there is currently no test instrument that can analyze The anti-interference ability of ISM frequency band products.

Contents of the invention

The invention aims to solve the problem that the anti-jamming ability of ISM frequency band communication products cannot be tested, thereby providing a method for testing the anti-interference ability of ISM frequency band wireless communication products.

The system for testing the anti-interference ability of ISM frequency band wireless communication products, which includes No. 1 adjustable attenuator, combiner, No. 2 adjustable attenuator, signal source and receiver bit error characteristic test equipment, and the ISM frequency band wireless communication products to be tested It includes a transmitter and a receiver, the signal transmitting end of the transmitter is connected to the signal receiving end of the No. 1 adjustable attenuator, and the attenuated signal output end of the No. 1 adjustable attenuator is connected to the No. 1 attenuating signal input end of the combiner; The signal transmitting end of the signal source is connected to the signal receiving end of the No. 2 adjustable attenuator, and the attenuated signal output end of the No. 2 adjustable attenuator is connected to the No. 2 attenuating signal input end of the combiner; the signal output end of the combiner It is connected with the signal receiving end of the receiver, and the bit error signal input end of the receiver bit error characteristic test equipment is connected with the bit error signal output end of the receiver.

Based on the described test ISM frequency band wireless communication product anti-jamming ability test method of above-mentioned system, it is realized by the following steps:

Step 1. Power up the transmitter, receiver, signal source and receiver bit error characteristic test equipment after debugging, the transmitter transmits the signal to the calibrated No. 1 adjustable attenuator, and attenuates through the No. 1 adjustable attenuator Then input to the combiner; use the signal source to transmit broadcast system signal, analog communication system signal, public cordless telephone system signal, public communication system signal, satellite communication system signal, special communication system signal, wireless access system signal and special radio Apply the system signal to adjust the reference attenuation value of the No. 2 adjustable attenuator after calibration, and use the receiver bit error characteristic test equipment to observe the bit error situation of the receiver. When the preset bit error rate range is reached, stop adjusting the No. 2 adjustable attenuator. Adjustable attenuator to obtain useful signal power and interference signal power of various system signals received by the receiver at this time;

Step 2, change the output power of the signal source, and repeat step one N times; said N is an integer; obtain the useful signal power and the interference signal power of various system signals received by the receiver under different signal source output powers; then Execute step three;

Step 3. Change the type of interference signal output by the signal source, and repeat step 1 to step 2; obtain the useful signal power and interference signal power of various system signals received by the receiver under different signal source output signal forms;

Step 4. According to the actual use environment of the product, select the corresponding radio wave propagation model. Under the condition that the output power of the transmitter and the output power of the signal source are known, through the various system signals received by the receiver in steps 1 to 3 The useful signal power and the interference signal power are used to calculate the distance between the transmitter and the receiver and the distance between the receiver and the signal source when the receiver is in the preset bit error rate range under the interference environment of various systems, so that Realize the quantitative analysis of the anti-interference ability of ISM frequency band wireless communication products.

Before the test, the transmitter is debugged. The modulation process is: use a power meter to calibrate the output power of the transmitter, and use a spectrum analyzer to test the output power spectrum of the transmitter; until the output power of the transmitter and the output power spectrum of the transmitter When all meet the predetermined requirements, the commissioning of the transmitter is completed.

Before the test, calibrate the No. 1 adjustable attenuator and the No. 2 adjustable attenuator. The calibration method is: use a vector network analyzer to calibrate the No. 1 adjustable attenuator in the working frequency band of the ISM band wireless communication product to be tested. attenuator and the second adjustable attenuator for calibration.

Obtaining the useful signal power of various system signals received by the receiver in step one is obtained by the following formula, which is: useful signal power received by the receiver=transmitter output power-No. 1 adjustable attenuation Baseline attenuation value of the attenuator - long transmission line loss - combiner loss - transmission line loss between the transmitter and the No. 1 adjustable attenuator - transmission line loss between the receiver and the combiner.

Obtaining the interference signal power of each system received by the receiver in step 1 is obtained by the following formula, which is: interference signal power received by the receiver=signal source output power-signal source and No. 2 adjustable Transmission line loss between attenuators - Attenuation value of No. 2 adjustable attenuator - Transmission line loss between No. 2 adjustable attenuator and combiner - Combiner loss - Transmission line loss between combiner and receiver .

The radio wave propagation model described in step 4 is a free space propagation model, and the free space propagation model is:

Loss _free-space ＝32.45+201g M(MHz)+201g D(km)

In the formula: D refers to the distance between the transmitter and the receiver, the unit is km; M refers to the carrier frequency of the communication signal, the unit is MHz.

Beneficial effects: the invention can realize the anti-jamming performance test of ISM frequency band communication products with high accuracy.

Description of drawings

Fig. 1 is a schematic structural diagram of the system of the present invention.

Detailed ways

Specific embodiments 1. This specific embodiment is described in conjunction with FIG. 1, a system for testing the anti-interference ability of ISM frequency band wireless communication products, which includes No. 1 adjustable attenuator 2, combiner 3, and No. 2 adjustable attenuator 4 , signal source 5 and receiver bit error characteristic testing equipment 7, the ISM frequency band wireless communication product to be tested comprises transmitter 1 and receiver 6, and the signal transmitting end of transmitter 1 is connected with the signal receiving end of No. 1 adjustable attenuator 2 , the attenuated signal output end of No. 1 adjustable attenuator 2 is connected with the No. 1 attenuated signal input end of combiner 3; the signal transmitting end of signal source 5 is connected with the signal receiving end of No. 2 adjustable attenuator 4, and No. 2 The attenuated signal output end of the adjustable attenuator 4 is connected to the No. 2 attenuated signal input end of the combiner 3; the signal output end of the combiner 3 is connected to the signal receiving end of the receiver 6, and the receiver bit error characteristic test equipment 7 The error signal input end of the receiver 6 is connected with the error signal output end of the receiver 6.

The working principle is as follows: According to the working frequency band of the communication product, by analyzing which frequency spectrum of the existing common radio communication system will coincide with the working frequency band of the communication product, and then connect the signal source 5 to the second adjustable attenuator 4 to simulate different common radio communication The distance between the system and the receiver, and finally analyze the impact of various common radio communication systems on the communication receiver.

Specific embodiment two, based on the test method of the system of a kind of test ISM frequency band wireless communication product anti-jamming ability described in this specific embodiment one, it is realized by the following steps:

Step 1. Power up the transmitter 1, receiver 6, signal source 5 and receiver bit error characteristic test equipment 7 after debugging, and the transmitter 1 transmits the signal to the calibrated No. 1 adjustable attenuator 2. No. 2 adjustable attenuator 2 is attenuated and then input to combiner 3; the signal source 5 is used to transmit the system signals as described in Table 1 respectively, and the reference attenuation value of No. 2 adjustable attenuator 4 after calibration is adjusted. The code characteristic test equipment 7 observes the bit error situation of the receiver 6, and when the preset bit error rate range is reached, the adjustment of the No. 2 adjustable attenuator 4 is stopped, and the power sum of the useful signals of each system received by the receiver 6 is obtained. Interference signal power, and recorded in Table 2;

Table 1

Table 2

Step 2, change the output power of the signal source 5, repeat step one N times; said N is an integer; obtain the power and the interference signal power of the useful signals of each system received by the receiver 6 under different signal source 5 output powers ;

Step 3, change the type of interference signal output by signal source 5, and repeat step 1 to step 2; obtain the power and interference signal power of useful signals received by receiver 6 under different signal source 5 output signal forms;

Step 4. According to the actual use environment of the product, select the corresponding radio wave propagation model. Under the condition that the output power of the transmitter is known and the output power of the signal source is known, the useful information of each system received by the receiver 6 in steps 1 to 3 The power of the signal and the power of the interference signal are calculated in the interference environment of each system and when the receiver 6 is in the preset bit error rate range, the distance between the transmitter 1 and the receiver 6 and the distance between the receiver 6 and the signal source 5 distance, so as to achieve quantitative analysis of the anti-interference ability of ISM band wireless communication products.

The debugging process of transmitter 1 is: use a power meter to calibrate the output power of transmitter 1, and use a spectrum analyzer to test the output power spectrum of transmitter 1; until the output power of transmitter 1 and the output power spectrum of transmitter 1 meet the predetermined requirements , the debugging of transmitter 1 is completed.

The calibration method of the No. 1 adjustable attenuator 2 and the No. 2 adjustable attenuator 4 is: in the working frequency band of the ISM band wireless communication product to be tested, the No. 1 adjustable attenuator 2 and the No. Calibration of attenuator 4.

Obtaining the power of the useful signals of each system received by the receiver 6 in step one is obtained by the following formula: said formula is: the useful signal power received by the receiver=transmitter output power-No. 1 adjustable attenuation Baseline attenuation value of the attenuator - long transmission line loss - combiner loss - transmission line loss between the transmitter and the No. 1 adjustable attenuator - transmission line loss between the receiver and the combiner

Obtaining the interference signal power of each system received by the receiver 6 in step one is obtained by the following formula:

The interference signal power received by the receiver = output power of signal source - transmission line loss between signal source and No. 2 adjustable attenuator - attenuation value of No. 2 adjustable attenuator - difference between No. 2 adjustable attenuator and combiner Transmission line loss between - combiner loss - transmission line loss between combiner and receiver.

The radio wave propagation model described in step 4 is a free space propagation model, and the free space propagation model is:

Loss _free-space ＝32.45+201g M+201g D

In the formula: D refers to the distance between the transmitter and the receiver, the unit is km; M refers to the carrier frequency of the communication signal, the unit is MHz.

Claims (7)

1. the system of test I SM frequency range wireless communications products antijamming capability, it is characterized in that: it comprises an adjustable attenuator (2), mixer (3), No. two adjustable attenuators (4), signal source (5) and receiver bit error performance testing equipment (7), ISM band wireless communications products to be measured comprises transmitter (1) and receiver (6), the signal transmitting terminal of transmitter (1) is connected with the signal receiving end of an adjustable attenuator (2), and the deamplification output of an adjustable attenuator (2) is connected with a deamplification input of mixer (3); The signal transmitting terminal of signal source (5) is connected with the signal receiving end of No. two adjustable attenuators (4), and the deamplification output of No. two adjustable attenuators (4) is connected with No. two deamplification inputs of mixer (3); The signal output part of mixer (3) is connected with the signal input part of receiver (6), and the bit error signal input of receiver bit error performance testing equipment (7) is connected with the bit error signal output of receiver (6).

2. based on the method for testing of the system of the described test I SM frequency range of claim 1 wireless communications products antijamming capability, it is characterized in that: it is realized by following steps:

Step 1, transmitter (1), receiver (6), signal source (5) and the receiver bit error performance testing equipment (7) that will debug after qualified power up, transmitter (1) adjustable attenuator (2) to calibration that transmits inputs to mixer (3) after an adjustable attenuator (2) decay; Adopt signal source (5) to launch the broadcast system signal respectively, the analog communication system signal, public's cordless telephone system signal, the public communication system signal, the satellite communication system signal, the personal communication system signal, wireless access system signal and extraordinary radio application system signal, adjust the benchmark pad value of No. two adjustable attenuators (4) after calibrating, adopt the error condition of receiver bit error performance testing equipment (7) observation receiver (6), when reaching default error rate scope, stop to adjust No. two adjustable attenuators (4), the available signal power and the interfering signal power of the various system signals that acquisition receiver this moment (6) receives;

Step 2, the power output of signal source (5) of changing, repeated execution of steps one N time; Described N is an integer; The available signal power and the interfering signal power of the various system signals that the receiver (6) under the power output of acquisition unlike signal source (5) receives; Execution in step three then;

The interference signal type of step 3, change signal source (5) output, repeated execution of steps one is to step 2; The available signal power and the interfering signal power of the various system signals that the receiver (6) under acquisition unlike signal source (5) the output interference signal type receives;

Step 4, actual environment for use according to product, select corresponding radio waves propagation model, known in transmitter (1) power output, under the known condition of signal source (5) power output, the available signal power and the interfering signal power of the various system signals that receive by receiver in the step 1 to three (6) calculate under the interference environment of various systems, receiver (6) is in when presetting error rate scope, distance between distance between transmitter (1) and the receiver (6) and receiver (6) and the signal source (5), thereby the antijamming capability of realization quantitative analysis ISM band wireless communications products.

3. the method for testing of the system of test I SM frequency range wireless communications products antijamming capability according to claim 2, it is characterized in that before test, to debugging of transmitter (1), its modulated process is: adopt power meter to demarcate the power output of transmitter (1), adopt the output power spectrum of frequency spectrograph test receiver (1); When the output power spectrum of the power output of transmitter (1) and transmitter (1) all satisfies pre-provisioning request, finish debugging to transmitter (1).

4. the method for testing of the system of test I SM frequency range wireless communications products antijamming capability according to claim 2, it is characterized in that before test, an adjustable attenuator (2) and No. two adjustable attenuators (4) are carried out calibration steps, its calibration steps is: in the working frequency range of ISM band wireless communications products to be measured, adopt vector network analyzer that an adjustable attenuator (2) and No. two adjustable attenuators (4) are calibrated.

5. the method for testing of the system of test I SM frequency range wireless communications products antijamming capability according to claim 2, the available signal power that it is characterized in that the various system signals that the described acquisition receiver of step 1 (6) receives obtains by following formula, and described formula is: transmission line loss-receiver between the benchmark pad value of available signal power=output power of transmitter that receiver is received-No. one adjustable attenuator-long transmission line loss-mixer loss-transmitter and the adjustable attenuator and the transmission line loss between the mixer.

6. the method for testing of the system of test I SM frequency range wireless communications products antijamming capability according to claim 2, the interfering signal power that it is characterized in that each system that the described acquisition receiver of step 1 (6) receives obtains by following formula, and described formula is: pad value-No. two adjustable attenuator and the transmission line loss-mixer loss-mixer between the mixer and the transmission line loss between the receiver of transmission line loss-No. two adjustable attenuator between the interfering signal power that receiver is received=signal source power output-signal source and No. two adjustable attenuators.

7. the method for testing of the system of test I SM frequency range wireless communications products antijamming capability according to claim 2 is characterized in that radio waves propagation model described in the step 4 is the free space propagation model, and described free space propagation model is:

Loss _free-space=32.45+20lgM+20lgD

In the formula: D is meant the distance between transmitter and the receiver, and unit is km; M is meant the carrier frequency of signal of communication, and unit is MHz.

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