CN103138855B - A kind of radio network information channel analog based on outfield measured data and method - Google Patents

Abstract

The present invention provides a method and device for constructing a wireless network channel simulation environment in a laboratory. The method includes: collecting channel fading data of each base station and each user terminal in the wireless network, and analyzing each channel fading data to form a channel simulation When performing channel simulation on a scene, the signal sent by the corresponding base station antenna is received according to the simulated scene, and the received signal is channelized with the parameter channel number corresponding to the scene, and then output from the corresponding output port. By adopting the technical solution of the present invention, the signal can be processed in the baseband, and the radio frequency data can also be processed, and the slow fading of the external field signal can be simulated, and the multipath fast fading can also be simulated, and the channel simulation of the network level can be provided, and it can be used for The simulated channel scripts all come from the real field environment, so that the actual field environment can be simulated more realistically, and the field test can be realized in the laboratory.

Description

A wireless network channel simulation device and method based on field measured data

technical field

The invention relates to the field of wireless communication, in particular to a simulation device and method for complicated external field wireless network channels.

Background technique

The electromagnetic wave propagation characteristics of wireless channels are related to the propagation environment (geographical features, buildings, electromagnetic interference, frequency bands, etc.). In general, we believe that wireless channels have two characteristics: large-scale fading and small-scale fading, among which large-scale fading describes The attenuation or path loss of the average received signal power caused by the mobile station moving over a large distance has two influencing factors: path loss and shadow fading. Path loss refers to the propagation loss of radio waves in space; shadow fading refers to the shadow area of electromagnetic field that will be generated when radio waves are blocked by tall obstacles during propagation. When the mobile station passes through the shadow area, it will cause the median signal field strength In general, there is no direct signal between the base station and the mobile station, and the received signal is usually a superimposed signal after the transmitted signal has undergone several times of diffraction, scattering, reflection, transmission, and refraction. The phenomenon that the path reaches the receiving end is called multipath propagation. Multipath propagation causes signal waveform broadening, resulting in frequency selective fading; the Doppler effect affects the time-varying characteristics of the channel, and the Doppler frequency offset caused by the moving speed causes the signal spectrum to spread within a certain range, resulting in time selection Sexual decline. This kind of small-scale fading will cause the power fading of tens of dB of the signal. At the same time, the wireless network channel is also affected by various electromagnetic interference and co-frequency interference in networking.

The complexity and time-varying nature of wireless network channels make wireless network planning and system parameter configuration more difficult, making system testing unable to cover various complex scenarios in practical applications. After the wireless communication equipment (such as base station, terminal) completes various performance index tests in the laboratory research and development stage, it needs to conduct network testing in the actual wireless channel environment. In order to verify the stability and maturity of wireless communication equipment, it is generally necessary to open up a large Large-scale test bureaus to verify the rationality of network planning and system parameter settings, and fully expose the defects of products in practical applications. This verification and testing method has a long development cycle and a large investment, which is not conducive to quickly verifying the commercial capabilities of wireless products.

In the prior art, one of them proposes a wireless channel simulation method and device, which can perform multipath fading processing on the baseband signal, but it cannot handle the slow fading of the signal, nor can it process the signal at radio frequency; the other The prior art proposes a multipath fading test system and test method for mobile terminals in a mobile communication network, which is characterized in measuring the wireless network channel, but does not care about the channel characteristics of the measurement; there is also a prior art that proposes a MIMO The channel simulation device considers the time and frequency fading and spatial selective fading at the same time, and can simulate multi-dimensional space parameters, but it is only a simulation calculation of theoretical parameters, which is quite different from the real external field environment.

Synthesizing existing technologies, the simulation of wireless channels is divided into soft simulation and hard simulation. Among them, the soft simulation is based on the classic channel model in the industry, and simulates and approximates the wireless channel through mathematical modeling. The defect is that these channel models only model the classic application scenarios, and cannot truly reproduce the diversity and complexity of the channel. ;The hard simulation is based on the wireless channel simulator. The wireless channel simulator can generate channel parameters according to the channel model, and can also download the collected data of the actual channel. This method has a better simulation effect for point-to-point wireless channel simulation, but it does not The simulation ability of the channel is poor, and it is generally completed by cascading multiple wireless channel simulators (as shown in Figure 1). Due to the large size of the channel simulator and the synchronization problem between signals, even cascading can only Realize small-scale network simulation.

Contents of the invention

In order to solve the above problems, the present invention proposes a method and device for constructing a wireless network channel simulation environment in the laboratory, using the data collected from the actual channel environment to simulate the signals between the base station and the mobile station group in the laboratory External field environment processing, through the control of channel scripts, can flexibly realize various interference simulation tests in single-antenna, multi-antenna (MIMO: multiple input multiple output) channels and complex network environments, and best match the actual channel environment in the external field. The laboratory builds a virtual wireless network environment to test and evaluate the performance of system products, and plays the test function of the scale experiment bureau.

The purpose of the present invention is to propose a method and device for wireless network channel simulation in the laboratory, through the channel data collection of the actual network environment, reconstruct and reflect the real characteristics of the actual wireless network in the laboratory, and construct a virtual wireless network. Network environment test, evaluate the performance of system products.

The present invention provides a wireless network channel simulation method based on field measured data, including:

Collect the channel fading data of each base station and each user terminal in the wireless network, and analyze the channel fading data to form the channel parameters required for channel simulation; when performing channel simulation for a scene, receive the corresponding base station antenna according to the simulated scene The sent signal is channelized with the parameter channel number corresponding to the scene, and then output from the corresponding output port.

Further, before channelizing the received signal, generate a corresponding test script according to the scene to be simulated, including an input script, an output script and a channel script;

The input script refers to the base station number and antenna number that need to be used in the current scene;

The output script is a group of terminals and antenna numbers in the current scene;

The channel script is channel parameters, including slow fading, fast fading of each multipath, and relative time delay of each fast fading.

Further, the method further includes: receiving a signal sent by a corresponding base station antenna according to the input script, and buffering the received baseband data in an order in which the antenna is arranged.

Further, if the radio frequency signal sent by the antenna of the base station is received, the radio frequency signal is converted into baseband data and then buffered.

Further, performing channelization processing on the received signal refers to:

Read the buffered signals and corresponding channel parameters according to the input script, and then perform operations in the following manner:

Multiply the baseband data by the slow decay value to get W1, and then multiply the fast decay values of each path by W1, if there are n fast decay values, then each fast decay value is multiplied by W1 to get W21, W22...W2n , and then, use the fast decay time delay of each path to perform delay processing on the corresponding W2i to obtain W31, W32...W3n respectively, and finally perform superposition processing on W31, W32...W3n;

The 1≤i≤n.

Further, the outputting the processed signal from the corresponding output port refers to outputting the processed signal from the corresponding terminal port according to the output script.

The present invention also provides a wireless network channel simulation device based on field measured data;

The device includes a channel script management control background, a channelization processing module, an input baseband control module and an output baseband control module;

The channel script management control background is used to analyze the received channel data collected in the field to obtain the channel parameters required for channel simulation;

The input baseband control module is used to receive and cache the baseband data sent by the base station antenna;

The channelization processing module is used to read the baseband data of the corresponding scene and the corresponding channel parameters, perform channelization processing on the baseband data according to the channel parameters, and send the processed signal to the output baseband control module;

The output baseband control module is used to output the processed signal to the corresponding terminal port.

Further, the device also includes a channel data classification delivery module, which is used to extract corresponding channel parameters according to the simulated scene and form a test script;

The test scripts include input scripts, output scripts and channel scripts;

The input script refers to the base station number and antenna number that need to be used in the current scene;

The output script is a group of terminals and antenna numbers in the current scene;

The channel script is channel parameters, including slow fading, each multipath fast fading, and the relative time delay of each fast fading;

The channel data classification delivery module is also used to deliver the input script to the input baseband control module, deliver the output script to the output script control module, and deliver the channel script to the channelization processing module.

Further, the device further includes a radio frequency processing module, configured to convert the received radio frequency signal sent by the base station antenna into baseband data and send it to the input baseband control module.

Further, the input baseband control module receiving and buffering the baseband data sent by the base station antenna refers to: the input baseband control module receives the signal sent by the corresponding base station antenna according to the input script, and buffers the received signal according to the order of antenna sorting.

Further, the channelization processing by the channelization processing module refers to: the channelization module reads the cached baseband data and corresponding channel parameters, multiplies the baseband data by the slow decay value to obtain W1, and then uses the fast decay values of each path to obtain W1 respectively Multiply by W1, if there are n fast decay values, then each fast decay value is multiplied by W1 to get W21, W22...W2n, then, use the fast decay time delay of each path to delay the corresponding W2i respectively Get W31, W32...W3n, and finally superimpose W31, W32...W3n;

The 1≤i≤n.

Further, the said output baseband control module outputting the processed signal to the corresponding terminal port refers to: the output baseband control module outputs the processing result from the corresponding terminal port according to the output script.

Compared with the prior art, the wireless network channel simulation device proposed by the present invention has the following advantages: support point-to-point simulation (single-input-single-output situation) and network-level simulation (multiple-input-multiple-output situation) simultaneously; It can also process radio frequency data, which can not only simulate the slow fading of external field signals, but also simulate multipath fast fading at the same time, and can provide network-level channel simulation, and the channel scripts used for simulation are all derived from the real external field environment , so that the actual field environment can be simulated more realistically, so that the field test can be realized in the laboratory.

Description of drawings

Fig. 1 is the schematic diagram that channel emulator builds wireless network in the prior art;

Fig. 2 is a schematic structural diagram of a wireless network channel simulation device of the present invention;

Fig. 3 is the flowchart of network channel simulation in the method embodiment of the present invention;

FIG. 4 is a schematic diagram of a channel parameter matrix in an embodiment of the present invention;

FIG. 5 is a structural diagram of channelization processing in an embodiment of the present invention;

Fig. 6 is a point-to-point channel simulation example diagram in application example 1 and application example 2 of the present invention;

FIG. 7 is a schematic diagram of a wireless network structure in Application Example 3 of the present invention.

detailed description

The present invention provides a wireless network channel simulation device and method based on field measured data, collects channel fading data of each base station and each user terminal in the wireless network, and analyzes each channel fading data to form parameters required for channel simulation ; When channel simulation is performed on a scene, the signal sent by the corresponding base station antenna is received according to the simulated scene, and the received signal is channelized with the parameters corresponding to the scene, and then output from the corresponding output port.

Device embodiment

The basic structure of the wireless network channel simulation device of the present invention is shown in Figure 2, including a channel script management control background, a channel data classification delivery module, a channelization processing module, an input baseband control module, an output baseband control module and a radio frequency processing module Composition, the functions of each part are described as follows:

Channel script management control background (such as computer, server, etc.): used to analyze the channel data collected by the field channel data acquisition system, determine the power delay distribution, angular power spectrum distribution, channel spatial correlation, large-scale fading characteristics, etc. of the multipath channel , the actual channel network in the field is abstracted into specific large-scale fading parameters and small-scale fading parameter groups. The large-scale fading parameters are to smooth the collected data, and then extract its amplitude characteristics; characteristics, separate out its channel multipath components, and then extract the power and delay information. That is, a data combination capable of characterizing fast fading and slow fading parameters of an actual channel is generated.

Channel data classification delivery module: generate test scripts based on the data generated in the background according to the current channel processing needs (that is, according to the current simulated scene), including input scripts (that is, input control parameters), output scripts (that is, output control parameters) and Channel script (that is, channel parameters); and send the input script, output script and channel script to the input baseband control module, output baseband control module and channelization processing module respectively; wherein, the input script is the base station that needs to be used in the current scene number and antenna number; the output script is a group of UEs and antenna numbers in the current scenario; the channel script includes parameters such as slow fading, fast fading of each multipath, and relative delay of each fast fading.

The input baseband control module is used to extract the required base station antenna data from the received input data according to the cached input script, and arrange and cache according to the antenna requirements, that is, according to the actual scene to be simulated, select the base station involved in the scene The baseband data sent by the antennas, and the data sent by each antenna are stored in different buffers for use by the channel processing module. For example, a scene involves base station 1, base station 2, and base station 4, and base station 1 includes antenna 1, and base station 2 includes Antenna 1 and antenna 2, base station 4 includes antenna 3, and the input baseband control module arranges the baseband data sent by these 4 antennas into 1234 in sequence.

Channelization processing module: read the baseband data of the corresponding antenna in the corresponding buffer in real time according to the input control parameters, and at the same time read the channel parameters corresponding to the current scene for calculation, and send the calculation result to the output baseband control module;

Specifically, the operation method is: multiply the baseband data by the slow decay value to obtain W1, and then multiply the fast decay values of each path by W1 respectively. If there are n fast decay values, each fast decay value is multiplied by W1 to obtain W21, W22...W2n, and then use the fast decay time delay of each path to perform delay processing on the corresponding W2i to obtain W31, W32...W3n respectively, and finally perform superposition processing on W31, W32...W3n.

The output baseband control module is used to output the received calculation result to the corresponding UE antenna according to the actual scene, that is, to output the channel-processed signal of the antenna involved in the scene to the corresponding UE antenna.

The radio frequency processing module is used to convert the received radio frequency signal sent by the base station antenna into a baseband signal and send it to the input baseband control module when the radio frequency part of the base station and the UE needs to process the radio frequency signal; The signal is converted into a radio frequency signal and sent to the UE.

If the base station and the UE only have the baseband part, then the device can be directly connected through an optical fiber, and directly communicate with the base station and the UE at the baseband part.

method embodiment

The implementation steps of the wireless network channel simulation device of the present invention are shown in Figure 3, and the specific process is:

Step S1, collect the channel fading data of each base station and each user terminal (or channel collection device) in the actual wireless network, the movement route of the user terminal should cover the entire wireless network environment as much as possible, and the collection time should be long enough;

Step S2, analyzing and processing the collected channel data to obtain various channel parameters required for channel processing.

For each channel data, the actual channel data in the external field is abstracted into ideal channel parameters, and parameters such as slow fading, fast multipath fading, and relative time delay of each fast fading are obtained; specifically, for large-scale fading characteristics, it is necessary to analyze the data Perform smoothing to eliminate the influence of interference noise, and then extract its amplitude characteristics; for small-scale fading features, according to the characteristics of the signal frequency, it is necessary to separate the channel multipath components, extract the power delay information, and finally make a channel parameter matrix table, such as Figure 4 shows.

Step S3: Generate a test script according to the current scene to be simulated, and distribute the data by classification;

Specifically, according to the scene currently to be simulated, corresponding data is extracted from the background to generate a test script, including an input script (ie, input control parameters), an output script (ie, output control parameters) and a channel script (ie, channel parameters); and the input The script, output script and channel script are sent to the input baseband control module, output baseband control module and channelization processing module respectively; among them, the input script is the base station number and antenna number that need to be used in the current scene; the output script is the A group of UEs and antenna numbers below; the channel script includes parameters such as slow fading, fast fading of each multipath, and relative delay of each fast fading. Then send the input script to the input baseband control module, send the output script to the output baseband control module, and send the channel script to the channelization processing module.

As shown in FIG. 4 , the numbers corresponding to the right side of the base stations in the vertical column are the input port numbers, and the numbers corresponding to the lower side of the UEs in the horizontal row are the output port numbers. The corresponding H value in the middle of the table indicates the channel value under the corresponding input-output mapping relationship, and each H value includes the slow fading, multipath fast fading and the time delay corresponding to the fast fading of the channel data. Finally, this part will store the input number, output number, slow decay value, fast decay value of each path, and fast decay delay into different buffer buffers, and read them when waiting for channel processing.

Step S4: Receive and store the signal from the corresponding base station antenna according to the input script; specifically, determine the antenna port of the base station according to the input script, and then receive the signal sent by the port. If the received radio frequency signal is received, first convert the radio frequency signal into The baseband signal is stored later, if the baseband signal is received, it is stored directly, and the storage is stored in the order of the antennas specified in the input script.

Step S5: output the processed signal after the channelization processing. As shown in Figure 5, this part is the core part of the device, and the specific steps are as follows:

First, read the input data stored in the buffer, and read the corresponding channel script (that is, channel parameters), and then perform calculations on the input data according to the channel parameters; the calculation method is: multiply the baseband data by the slow decay value to obtain W1, and then Multiply the fast decay value of each path by W1, if there are n fast decay values, each fast decay value is multiplied by W1 to get W21, W22...W2n, then, use the fast decay time delay of each path to correspond to Delay processing of W2i to obtain W31, W32...W3n respectively, and finally perform superposition processing on W31, W32...W3n;

Finally, according to the output script, the channelized data is sent to the corresponding output port.

further,

If the test script required by the current scene changes in real time, it is necessary to generate the test script in real time according to the current scene, and process the signal by receiving corresponding signals and reading corresponding channel parameters according to the test script.

Several implementation modes are given below to illustrate some typical application situations of the present invention:

Application example 1: Point-to-point channel simulation.

As shown in Figure 6, in the case of only one base station and one UE, the transmitting antenna of the base station sends radio frequency data to the air interface, and the radio frequency unit of this device converts the received radio frequency data into baseband data and sends them to the input baseband control module Then, according to the needs of the test, select the H value formed by the antenna port of the base station and the terminal port required in the corresponding scene, compose the H value into a test script from the channel script management control background, send the module through the channel data classification, and decompose it into The input script, the output script and the channel script are respectively sent to the input baseband control module, the output baseband control module and the channelization processing module; the channelization processing module performs comprehensive calculation on the above data according to the aforementioned channel processing algorithm, and then outputs to the radio frequency processing module, and finally sent to the air interface; finally, the UE receives the channelized data. By controlling the changes of background scripts, channel conditions in various scenarios can be simulated.

Application example 2: Channel simulation of baseband signals.

As shown in Figure 6, when there is no radio frequency equipment, the base station or UE can also carry out the simulation test by the wireless network channel simulation device of the present invention; at this time, the radio frequency unit of the present invention can be bypassed, the baseband signal of the base station and the The input baseband processing module of the invention is directly connected by optical fiber; similarly, the output baseband processing module and UE without radio frequency are also connected by optical fiber direct connection. Similarly, channel changes in various scenarios can also be simulated through background script changes.

Application example 3: Wireless network simulation in the case of three cells and two UEs.

As shown in Figure 7, in the case of three base stations and two UEs, the transmitting antennas of the three base stations send radio frequency data to the air interface, and the radio frequency unit of this device converts the received radio frequency data into baseband data and sends them to the input The baseband control module, the baseband control module numbers and sorts the incoming baseband data according to certain rules, base station 1, base station 2, and base station 3; then, according to the needs of the test, a certain test script is managed from the channel script to control the background, and through the channel data Classified distribution modules are decomposed into input scripts, output scripts and channel scripts, and are sent to the input baseband control module, output baseband control module and channelization processing module; Input different base station signal combinations into the channel processing module; the channelization processing module performs comprehensive calculations on the above data according to the channel processing algorithm mentioned above, and sends them to the output baseband processing module; the output baseband processing module converts the processed data according to the script output number The data is sent to the corresponding air interface through the radio frequency processing module; finally, each UE receives the data processed by the corresponding base station or several base stations through channelization. By controlling the changes of background scripts, various scenarios of two UEs in a network of 3 base stations can be simulated, including cell handover, interference changes in adjacent areas, enhanced comp at the cell edge, etc.

Finally, it should be noted that the above description of the preferred embodiments of the present invention is relatively specific, and should not be considered as limiting the scope of protection of the present invention. The scope of protection of the present invention should be based on the appended claims.

Claims (11)

1. A wireless network channel simulation method based on field measured data, comprising: Collect the channel fading data of each base station and each user terminal in the wireless network, and analyze the channel fading data to form the channel parameters required for channel simulation; when performing channel simulation for a scene, receive the corresponding base station antenna according to the simulated scene Send the signal, and use the channel parameters corresponding to the scene to channelize the received signal and output it from the corresponding output port; Before channelizing the received signal, generate corresponding test scripts according to the scene to be simulated, including input scripts, output scripts and channel scripts; The input script refers to the base station number and antenna number that need to be used in the current scene; The output script is a group of terminals and antenna numbers in the current scene; The channel script is channel parameters, including slow fading, each multipath fast fading, and the relative time delay of each fast fading; The method further includes: receiving and buffering the baseband data sent by the base station antenna. 2. The method of claim 1, wherein: The method further includes: receiving signals sent by corresponding base station antennas according to the input script, and arranging the antennas in order to buffer the received baseband data. 3. The method of claim 1, further comprising: If the radio frequency signal sent by the antenna of the base station is received, the radio frequency signal is converted into baseband data and then buffered. 4. The method according to claim 2 or 3, characterized in that: The channelization processing of the received signal refers to: Read the buffered signals and corresponding channel parameters according to the input script, and then perform operations in the following manner: Multiply the baseband data by the slow decay value to obtain W1, and then multiply the fast decay values of each path by W1 respectively. If there are n fast decay values, each fast decay value is multiplied by W1 to obtain W21, W22...W2n, and then , use the fast decay time delay of each path to perform delay processing on the corresponding W2i to obtain W31, W32...W3n respectively, and finally perform superposition processing on W31, W32...W3n; 1≤i≤n. 5. The method according to claim 2 or 3, characterized in that: Outputting the processed signal from the corresponding output port refers to outputting the processed signal from the corresponding terminal port according to the output script. 6. A wireless network channel simulation device based on field measured data, characterized in that: The device includes a channel script management control background, a channelization processing module, an input baseband control module and an output baseband control module; The channel script management control background is used to analyze the received channel data collected in the field to obtain the channel parameters required for channel simulation; The input baseband control module is used to receive and cache the baseband data sent by the base station antenna; The channelization processing module is used to read the baseband data of the corresponding scene and the corresponding channel parameters, perform channelization processing on the baseband data according to the channel parameters, and send the processed signal to the output baseband control module; The output baseband control module is used to output the processed signal to the corresponding terminal port; The device also includes a channel data classification delivery module, which is used to extract corresponding channel parameters according to the simulated scene and form a test script; The test scripts include input scripts, output scripts and channel scripts; The input script refers to the base station number and antenna number that need to be used in the current scene; The output script is a group of terminals and antenna numbers in the current scene; The channel script is channel parameters, including slow fading, fast fading of each multipath, and relative time delay of each fast fading. 7. The device of claim 6, wherein: The channel data classification delivery module is also used to deliver the input script to the input baseband control module, deliver the output script to the output script control module, and deliver the channel script to the channelization processing module. 8. The device of claim 6, wherein: The device also includes a radio frequency processing module, which is used to convert the received radio frequency signal sent by the antenna of the base station into baseband data and send it to the input baseband control module. 9. The device according to claim 7 or 8, characterized in that: The input baseband control module receives the baseband data sent by the base station antenna and buffers means: the input baseband control module receives the signal sent by the corresponding base station antenna according to the input script, and buffers the received signal according to the antenna sorting order. 10. The apparatus of claim 7, wherein: The channelization processing of the channelization processing module refers to: the channelization module reads the cached baseband data and corresponding channel parameters, multiplies the baseband data by the slow decay value to obtain W1, and then multiplies W1 by the fast decay value of each path , if there are n fast decay values, then each fast decay value is multiplied by W1 to obtain W21, W22...W2n, and then, use the fast decay time delay of each path to delay the corresponding W2i to obtain W31, W32... W3n, and finally perform superposition processing on W31, W32...W3n; 1≤i≤n. 11. The apparatus of claim 7, wherein: The output baseband control module outputting the processed signal to the corresponding terminal port refers to: the output baseband control module outputs the processing result from the corresponding terminal port according to the output script.