WO2004084565A1

WO2004084565A1 - A method of detecting the random access collision of multi-user equipment

Info

Publication number: WO2004084565A1
Application number: PCT/CN2004/000219
Authority: WO
Inventors: Feng Li; Tiezhu Xu; Libao Zhang; Xiaolong Ran
Original assignee: Da Tang Mobile Communications Equipment Co., Ltd.
Priority date: 2003-03-18
Filing date: 2004-03-18
Publication date: 2004-09-30
Also published as: CN1275489C; CN1533203A

Abstract

The invention relate to a method of detecting the random access collision of user equipment (UE), which apply to a mobile communication system consisted of base station and a group of UE, the base station and UE use N orthogonal or quasi-orthogonal pseudo-random sequence as a group to perform random access. The detecting method includes: the base station perform the correlation operation to the random access signal received at the same moment with each pseudo-random sequence in order, obtain the related correlation window; and find out the biggest correlation peak value in the correlation result window, then partition the correlation peak value window and edge window; setting a threshold, compare it with the correlation result in the edge window of the correlation peak value window and correlation result window not including the correlation peak value window, when the condition is met, it is determined that more than one user equipment use the pseudo-random sequence attended in the correlation operation of the correlation result window to perform random access, then exist the access collision problem for two or more than two UE select the same pseudo-random sequence in the same frame to access the same base station.

Description

Method for detecting multi-user terminal random access conflict Technical field

The present invention relates to a wireless mobile communication technology, and more particularly, to a method for detecting a user terminal (UE) random access mobile communication system. A base station applying the method can detect multiple user terminals in the same frame. Possible access conflicts in access. Background of the invention.

Figure 1 shows a base station (BS) and n (n is a positive integer) user terminals.

(UE01, UE02 UEn). -In this mobile communication system consisting of at least one base station and a group of user terminals, using code division multiple access (CDMA) technology, if multiple user terminal uplinks (that is, from user terminal UE to base station BS) The synchronization of wireless links (1001, 1002, 100n) in the figure will greatly improve the communication performance of the entire system. The 2001 and 2002 200n in the figure indicate the downlink from the base station to each user terminal.

Referring to FIG. 2, in an uplink-synchronized CDMA system, the uplink synchronization of each user terminal is generally established through the following steps: (1) each user terminal sends a specific uplink synchronous random access signal on the uplink; (2 ) At the base station, the uplink timing information of each user terminal is obtained by detecting each uplink synchronous random access signal, and the base station then transmits a timing synchronization adjustment command (synchronization adjustment information) to each user terminal through a specific downlink channel (FACH); (3) Each user terminal adjusts its own timing according to this command, and accesses on a specific access channel (RACH). .

Due to the situation that multiple user terminals are allowed to access at the same time, the uplink synchronous random access signal of each user terminal usually uses an orthogonal or quasi-orthogonal pseudo-random sequence code (PN). In a mobile communication system using a pseudo-random sequence code to achieve random access by multiple user terminals, The orthogonality of the sequence code allows the base station to detect the simultaneous access of user terminals by detecting the uplink synchronization signals sent by each user terminal in the environment of a mobile channel.

In the mobile communication system composed of at least one base station and a group of user terminals shown in FIG. 1, a group (N) of orthogonal or quasi-orthogonal pseudo-random sequence codes ^, m ₂ ... _N (vector) can be allocated To the base station, one of the pseudo-random sequence codes will be selected by one of the user terminals in the group. The set of orthogonal or quasi-orthogonal pseudo-random sequence codes satisfies the following related characteristic relationships:

—. ―

m, ·, ι, 1 ― 1 ~ Ν

In the formula, it represents a dot product, and the result of the dot product of any two different (i ≠ j) orthogonal or quasi-orthogonal pseudo-random sequence code vectors in this set of (N) orthogonal or quasi-orthogonal pseudo-random sequence codes is 0 Or approximately 0; the point multiplication result of any two of the set of (N) orthogonal or quasi-orthogonal pseudorandom sequence codes (i = j) orthogonal or quasi-orthogonal pseudorandom sequence codes is a constant L .

The uplink synchronous random access signal sent by the user terminal contains a pseudo-random sequence code. In theory, the base station can use direct sequence convolution (linear correlation) or matched filtering, etc. using the relevant characteristics of the pseudo-random sequence code. A variety of mature related operation methods, and a series of corresponding judgment conditions are combined to detect the uplink synchronization signal of each user terminal.

In the system shown in FIG. 1, when a user terminal uses a randomly selected pseudo-random sequence code to access and establish a connection with a base station, two or more user terminals may select the same frame in the same frame. A case where a pseudo-random sequence code is accessed simultaneously with the same base station. In the random access process, the base station distinguishes each user terminal accessed in the same frame according to the pseudo-random sequence code. Therefore, when the above situation occurs, the base station cannot distinguish these users who have selected the same pseudo-random sequence code. Terminal, causing a conflict when a user terminal randomly accesses. If in the case of a conflict, the base station still normally responds to the user terminal in conflict, It is inevitable that reception confusion occurs between these user terminals and the base station, causing interference between the conflicting user terminals and the conflicting user terminals to other user terminals, and affecting the work of the entire system. Especially in an interference-limited system such as time division-synchronous code division multiple access (TD-SCDMA), when there is severe multipath interference and multiple access interference in a mobile channel, the performance of the entire system will be reduced.

If a conflict occurs, the base station can accurately and effectively detect the conflicting multi-user terminal, so that the base station can handle the conflicting user terminal reasonably, and the interference caused by the conflicting user terminal can be avoided to affect the normal operation of the system. Situation, increase system capacity. Summary of the Invention

The purpose of the present invention is to design a method for detecting random access conflicts of multiple user terminals. Based on detecting random access user terminals, and then detecting user conflicts in access conflicts, the base station can learn that In the frame, there may be two or more user terminals that select the same pseudo-random sequence code for simultaneous access.

The technical solution for achieving the purpose of the present invention may be as follows: A method for detecting random access conflicts of multiple user terminals, which is applied to a mobile communication system composed of at least one base station and a group of user terminals, the base station and the group The user terminal uses a set of N orthogonal or quasi-orthogonal pseudo-random sequence codes as the random access of the user terminal, and detects the pseudo-random sequence code selected by each randomly accessed user terminal, where N is a positive integer, It is characterized by the following steps:

A. The base station correlates the received random access signal of the user terminal containing the pseudo random sequence code information selected by the access user terminal at the same time with a pseudo random sequence code in the local pseudo random sequence code group of the base station. Operation to obtain a corresponding correlation result window, and the correlation operation starts from any pseudo-random sequence code in the pseudo-random sequence code group and continues until all N pseudo-random sequence codes are operated;

B. Find the maximum correlation peak point in each correlation result window; C. According to the position of each correlation peak point, divide the correlation peak window in the corresponding correlation result window;

D. Set a threshold for conditional comparison with the corresponding correlation result in each correlation peak window, or conditional comparison with the corresponding correlation result in the side window except the correlation peak window for each correlation result window. When the judgment condition is satisfied, It is determined that the pseudo-random sequence code participating in the related operation in step A is randomly selected by two or more user terminals to access, and there is an access conflict.

The technical solution to achieve the objective of the present invention may also be as follows: A method for detecting random access conflicts of multiple user terminals is applied to a mobile communication system composed of at least one base station and a group of user terminals, the base station and the A group of user terminals uses a group of N orthogonal or quasi-orthogonal pseudo-random sequence codes as the random access of the user terminal, and detects the pseudo-random sequence code selected by each randomly accessed user terminal, where N is a positive integer It is characterized by including the following steps:

A1. The base station correlates the received random access signal of the user terminal containing the pseudo-random sequence code information selected by the access user terminal to a pseudo-random sequence code in the local pseudo-random sequence code group of the base station at the same time. To obtain the corresponding relevant result window;

• B1. Find the maximum correlation peak point in the correlation result window;

C1. According to the position of the correlation peak point, a correlation peak window is divided in the correlation result window;

D1. Set the threshold and compare the conditions with the corresponding correlation results in the correlation peak window and the correlation result window except the correlation peak window. When the conditions are met, it is determined that the pseudo-random sequence code participating in the correlation operation in step A is two. Or two or more user terminals randomly select access, and there is an access conflict.

The step A1 starts from any pseudo-random sequence code in the pseudo-random sequence code group to perform related operations with the random access signal of the user terminal; and when the step D1 meets or does not meet the conditions, both Return to step A1, from the pseudo-random sequence code group, select another pseudo-random sequence code different from the pseudo-random sequence code of the current operation to perform related operations with the random access signal of the user terminal until all N pseudo-random operations are completed. The serial code. In the step, A1, the number N of pseudo-random sequence codes in the pseudo-random sequence code group is a variable number or a fixed number of at least 1.

The steps and related operations in A1 include:

1) the base station performs Fourier transform on the received access signal from the user terminal;

2) base

Get Fourier transform results:

3) The base station uses the Fourier transform result obtained in step 1) and the Fourier transform result obtained in step 2) to obtain a relevant operation result through a dot multiplication operation, and performs an inverse Fourier transform on the relevant operation result;

Obtaining a correlation result window in steps A1 and A1 includes: taking a norm for each element in the inverse Fourier transform result obtained in step 3), and deriving a correlation result window from the norm.

The norm taking includes the correlation power result or the correlation absolute amplitude result derived from the norm in the form of power or absolute amplitude.

In the step 3), the correlation operation result is obtained by performing a correlation operation including direct sequence correlation or matched filter correlation in a correlator.

In step B and Bl †, when the correlation result window in the form of power is obtained, the point with the highest power is found in the correlation power window as the correlation peak point; when the correlation result window in the form of absolute amplitude is obtained , Find the point with the largest absolute amplitude in the correlation absolute amplitude window as the correlation peak point.

The step (\ C1) includes: 1) giving the correlation peak window window length through the simulation process; 2) giving the relationship between the window length on both sides of the maximum correlation peak point and the correlation peak window window length through the simulation process; 3) according to Step 1) and the result of step 2), divide the position of the correlation peak window containing the maximum correlation peak point; 4) According to the result of step 3), obtain the position and size of the side window outside the correlation peak window in the correlation result window.

In the step 2), the window length on the side of the maximum correlation peak point is the window length of the correlation peak window. 1/3, the window length on the other side of the maximum correlation peak point is 2/3 of the correlation peak window window length.

The steps D and D1 include:

dll) take the maximum correlation peak, and / or the effective value of the maximum correlation peak, and / or the average value of the correlation results within the correlation peak window, and / or the average effective value of the correlation results within the correlation peak window;

dl2) traverse all correlation result values in the correlation result window except the correlation peak window, and / or valid values of the correlation results;

dl 3) The maximum correlation peak obtained by step dll and / or the average of the correlation results within the correlation peak window are subtracted from all correlation result values obtained by traversing step d 12 or the effective value of the maximum correlation peak obtained by step d 11 , And / or the average effective value of the correlation results within the correlation peak window is subtracted from the effective values of all the correlation results obtained in step dl2 to obtain the differences; dl4) The threshold T c corresponding to each difference is set through the simulation process , And compare with each difference, when the difference is less than the threshold T c, it is determined that the condition 1 is satisfied and continue to perform the following steps; when the difference is greater than or equal to the threshold T c, it is determined that the condition 1 is not satisfied, and the execution of the following is stopped Step dl5) Count the number that meets condition 1;

dl 6) The threshold T2 corresponding to the above number is set through the simulation process and compared with the number counted in step dl5. When the counted number is greater than the threshold T2, it is determined that the condition is satisfied, otherwise it is determined that the condition is not satisfied.

The invention is a method for detecting random access conflicts of multiple user terminals. In a wireless mobile communication system composed of at least one base station and a group of UBs, a set of (N) orthogonal or quasi-orthogonal pseudo-random sequence codes are allocated to the base station and the group of user terminal equipment, and each user terminal randomly One of the pseudo-random sequence codes is selected for random access. If two or more UBs randomly select the same pseudo-random sequence code in the same frame, a problem that the base station cannot identify each UE will occur, and a multi-UE access conflict will occur. In this case, if the base station does not detect the collision and directly responds to the UE, it will cause mutual interference between these conflicting UEs and these The interference of the conflicting UE to other UEs will seriously affect system performance.

By using the method provided by the present invention, an access conflict occurring when multiple UEs access the same frame can be detected, so that the system can reasonably deal with the conflicting UEs, which will avoid interference caused by the conflicting UEs and improve system performance.

With the detection method of the present invention, a random access conflict of a user terminal can be detected at any time. The method of the present invention makes use of the orthogonality of orthogonal or quasi-orthogonal pseudo-random sequence codes. One or more pseudo-random sequence codes in a randomly selected or designated pseudo-random sequence code group) performs a correlation operation (a total of N correlation operations) with each pseudo-random sequence code in the pseudo-random sequence code group, and Find the maximum correlation peak point and other correlation peak points in the results of each correlation operation among the N correlation operation results, and then compare the threshold Tc with the maximum correlation peak point or Other peak points to determine whether the two peak points are multipaths of the same UE or belong to two different UEs respectively. If it is determined that the threshold Tc is satisfied, and then the relevant peak point that satisfies the threshold T2 belongs to two different UEs, it can be determined that there is a UE random access conflict in the access signal.

At the same time, in order to improve the accuracy of conflict detection, one or more comparison thresholds (T c) may be given, which are related to the maximum correlation peak point and / or other correlation peak points other than the maximum correlation peak point and / or these correlation peak points. Compare the average value and effective value in a certain window range, and count the number of midpoints of the correlation results that exceed a certain threshold in the correlation results, and give one or more thresholds to determine the correlation result window. The time difference between the correlation result point that satisfies a given threshold and the maximum correlation peak point, determines whether the correlation result point that satisfies the given threshold is a multipath of the maximum correlation peak point or a signal from another UE.

Compared with the prior art, using the detection method provided by the present invention, as long as one or more reasonable detection thresholds are given, conflicts in multi-UE random access can be detected, and after the base station properly handles the conflicting UEs, Can effectively avoid interference caused by access conflicts and improve The performance of the entire system, especially interference-limited systems such as TD-SCDMA. Brief description of the drawings

FIG. 1 is a structural block diagram of a mobile communication system composed of a base station and n user terminals (UE);

FIG. 2 is a schematic diagram of a random access process of a user terminal; FIG. 4 is a schematic diagram of a division of a correlation peak window and a side window in a correlation window and a comparison with a given threshold condition. Mode of Carrying Out the Invention

The present invention is described in detail below with reference to the drawings.

In a wireless mobile communication system consisting of at least one base station and a group of user terminals, the base station and each user terminal in the group of user terminals are assigned a same set of orthogonal pseudo-random sequence codes ^, ₂ ... _mN , N is the number of orthogonal pseudo-random sequence codes in the group. When multiple user terminals randomly select a code from the set of orthogonal pseudo-random sequence codes for access, the base station receives a random access signal ^ sent by multiple UEs to multiple UEs of the base station in the same frame, and the signal includes Pseudo-random sequence code information randomly selected by each UE. When multiple UEs perform random access in the same frame, it may happen that two or more UEs randomly select the same pseudo-random sequence code. The present invention utilizes the orthogonality of the pseudo-random sequence codes, and correlates each pseudo-random sequence code ^ (i = l ~ N) in the pseudo-random sequence code group with the mixed signal ^ to obtain a correlation result ^ ,. The maximum correlation peak point and other correlation peak points found in the correlation result are compared with a set threshold to determine whether these peak points that satisfy the comparison condition are multipath of the same UE or belong to different UEs. If it is determined that the relevant peak point that satisfies the comparison condition belongs to multiple different UEs, it can be determined that a UE exists in the access signal Random access conflict, that is, it is determined that two or more UEs randomly select the same pseudo-random sequence code for access, and it is detected that a UE random access conflict exists.

It should be noted that, in order to improve the accuracy of conflict detection, one or more comparison thresholds may be given, which are related to the maximum correlation peak point and / or to other correlation peak points other than the maximum correlation peak point and / or to these correlation peak points. Compare the average and effective values of the correlation results within a certain window range, and count the number of midpoints of the correlation results that exceed a certain threshold in the correlation results, and give one or more thresholds to determine the correlation The time difference between the correlation points that satisfy a given threshold or thresholds in the result window or between these correlation points that meet the threshold or thresholds One multipath of a point is also a signal from another UE.

Referring to FIG. 3, an implementation process of a base station detecting a random access conflict of a user terminal is shown. In the TD-SCDMA system, the conflict detection method provided by the present invention is adopted, and matching filtering is used as a correlation operation, and random access conflicts of multiple UEs are detected according to a correlation operation result.

Step 301: The base station receives an access signal from a user terminal in the same frame including a pseudo-random sequence code randomly selected by each user terminal, and performs Fourier transform (FFT) on the signal:

Steps 302 and 303: The base station performs Fourier transform (FFT) on each pseudo-random sequence code in the local orthogonal pseudo-random sequence code group (total N), for example, starting from the first code i = 1 (can be from any One code starts):

M _i = FFTim ^, (i = 1 ~ N)

In step 304, the base station uses a matched filtering method to perform a correlation operation on the signals ^ and ^ signals (both sequence signals) that have undergone the FFT transformation in the foregoing steps, that is, performing a dot multiplication operation to obtain a correlation operation result. (Vector): Y _t = W ^ SIG

Step ^305, the correlation operation result of inverse Fourier sorrow (IFFT) transform, the result is obtained (vector):

= IFFT (i)

Step 306: Take the norm of each element in the vector: = | ξ. |, Where Ι Ι represents taking the norm of each element in the vector to obtain a form including power or absolute amplitude (but not limited to this) The correlation result window, where is the correlation result window in the form of power (hereinafter only the correlation result window in the form of power is described, the correlation result window in the form of absolute amplitude has the same process);

Step 307: Determine the size and position of the peak point (peak) in the correlation power (or absolute amplitude) window (Pi window), the size and position of the peak window Lp (equal to L1 + L2) (Pwb and Pwe), the side window wsl, The size and position of Ws2, and the specific determination process will be described with reference to FIG. 4:

1) The window length Lp of the peak window is given by simulation. The length should be set on the basis of several major multipaths that can contain the signal, and the window of the remaining side windows other than the peak window is given by simulation. Long Ws l and Ws2 ;.

2) Find the maximum power point in the relevant power window, that is, the peak point Peak, and based on the peak point Peak, according to the window length Lp of the peak window obtained by the simulation, Lp = LI + L2, Ll = Lp / 3 and L2 = 2Lp / 3 (designed for the characteristic of multipath delay), determine the beginning and end positions of the peak window (see Pwb and Pwe) and the side windows on both sides (see Wsl and Ws2); step 308 , Given a suitable threshold Tc through the simulation process, traverse all relevant power (or absolute amplitude) point values Ps ide in the side window except the peak window, and the statistics that exist in the side window (Wsl, Ws2) satisfy the following conditions Number of related power points count (when the number of statistically relevant power points that can satisfy the condition is zero, the detection can be ended, and it is not necessary to make a comparison with condition 2 in the following steps): peak-Ps ide <Tc (Condition 1);

Step 309, a suitable threshold T2 is given through the simulation process, and the statistical result count is compared with the given threshold T2: count> T2 (condition 2);

Step 310: If the above condition 2 is satisfied, it is determined that the Pside that satisfies the condition 1 is a relevant peak point of access by another UE, and there is an access conflict at this time, that is, there are two (or more than two) in the same frame. ) The UE selects the same pseudo-random sequence code for random access, and a collision occurs;

Steps 311 and 312, if the above condition 2 does not hold, then i = i + 1 and determine whether i is less than or equal to N. When i is greater than N, it indicates that all N pseudo-random sequence codes have been operated on, and the detection ends. Process, when i is less than or equal to N, return to step 303, and perform the related operations shown in the corresponding steps on the next (such as i + 1) pseudo-random sequence code (step 303 related operations to N pseudo-random sequence codes, It can be performed one by one in sequence, or one by one out of sequence. The key is to operate the N pseudo-random sequence codes once).

In the implementation, there may be multiple determinations for condition 1, and one of them may be selected or several of them may be executed to replace step 308. For example, replace peak with the average value of the relevant power points in the correlation peak window (window length L p); replace p ea k with the power RMS value at the peak point position or the power average value of the relevant power points in the correlation peak window, respectively Compare with the statistic value (instead of Ps ide) of all relevant power points outside the correlation peak window (window length L p) (side window) to obtain the number of correlation points that satisfy condition 1, and the corresponding threshold T at this time c The simulation process must be adjusted accordingly, and the threshold T2 in Condition 2 must be adjusted accordingly.

The average value involved can be calculated according to the length of the correlation peak window (L p); the effective value involved is the value after interference is removed.

Through the above method for detecting random access conflicts, it is possible to quickly and accurately detect When multiple UEs in a frame randomly access the same pseudo-random sequence code, the base station can process the conflicting UEs reasonably, and avoid the interference caused by the conflicting UEs from affecting the entire system.

Claims

Claim

1. A method for detecting random access conflicts of multiple user terminals, which is applied to a mobile communication system composed of at least one base station and a group of user terminals, the base station and the group of users are terminated, and each random access is detected The pseudo-random sequence code selected by the user terminal, where N is a positive integer, is characterized by including the following steps:.

A. The base station will receive the random access signal of the user terminal at the same time containing the pseudo random sequence code information selected by the access user terminal, and one of the pseudo random sequence code groups in the base station's local pseudo random sequence code group. Performing a correlation operation to obtain a corresponding correlation result window, the correlation operation starts from any pseudo-random sequence code in the pseudo-random sequence code group, and continues until all N pseudo-random sequence codes are operated;

B. Find the maximum correlation peak point in each correlation result window;

C. According to the position of each correlation peak point, divide the correlation peak value window in the corresponding correlation result window;

D. Set a threshold for conditional comparison with the corresponding correlation result in each correlation peak window, or conditional comparison with the corresponding correlation result in the side window except the correlation peak window for each correlation result window. When the judgment condition is satisfied, It is determined that the pseudo-random sequence codes involved in the related operations in step A are randomly selected for access by two or more user terminals, and there is an access conflict.

The method for detecting a random access conflict of a multi-user terminal according to claim 1, wherein in the step A, the number N of pseudo-random sequence codes in the pseudo-random sequence code group is at least Variable or fixed number of 1.

The method for detecting a random access conflict of a multi-user terminal according to claim 1, characterized in that the related operation in step A comprises:

1) The base station performs Fourier transform on the received access signal from the user terminal to obtain Get Fourier transform results;

2) The base station performs Fourier transform on the pseudo-random sequence codes in the local pseudo-random sequence code group to obtain the Fourier transform result:

Obtaining a correlation result window in step A includes: taking a norm for each element in the inverse Fourier transform result obtained in step 3), and deriving a correlation result window from the norm.

4. The method for detecting random access conflicts of multi-user terminals according to claim 3, characterized in that: said norms include powers derived from norms or correlation powers derived from norms Results or related absolute amplitude results.

The method for detecting random access conflicts of multi-user terminals according to claim 3, characterized in that: in step 3), the result of the correlation operation is performed in a correlator including direct sequence correlation or Correlation operations related to matched filtering.

6. The method for detecting a random access conflict of a multi-user terminal according to claim 1, characterized in that: in the step B, when a correlation result window in the form of power is obtained, the correlation power is Find the point with the highest power in the window as the correlation peak point. When the correlation result window in the form of absolute amplitude is obtained, find the point with the largest absolute amplitude in the correlation absolute amplitude window as the correlation peak point.

7. The method for detecting a random access conflict of a multi-user terminal according to claim 1, wherein said step C comprises: 1) giving a correlation peak window window length through a simulation process; 2) passing The simulation process gives the relationship between the window length on both sides of the maximum correlation peak point and the correlation peak window window length; 3) According to the results of step 1) and step 2), the position of the correlation peak window containing the maximum correlation peak point is divided; 4) According to the result of step 3), the position and size of the side window other than the correlation peak window are obtained in the correlation result window.

8. The method for detecting a random access conflict of a multi-user terminal according to claim 7, characterized in that in the step 2), the window length on the side of the maximum correlation peak point is the window length of the correlation peak window 1/3, the window length on the other side of the maximum correlation peak point is 2/3 of the correlation peak window window length.

9. The method for detecting a random access conflict of a multi-user terminal according to claim 1, wherein the step D comprises:

dl 3) The maximum correlation peak obtained in step dl l and / or the average value of the correlation results in the correlation peak window are subtracted from all correlation result values obtained in step d 12 traversal, or the maximum correlation peak obtained in step d 11 is valid. Value, and / or the average effective value of the correlation results within the correlation peak window, respectively minus the effective values of all correlation results obtained in step dl2 to obtain each difference; dl4) Set the threshold T c corresponding to each difference through the simulation process And compare with each difference, when the difference is less than the threshold T c, determine that condition 1 is satisfied and continue to perform the following steps; when the difference is greater than or equal to the threshold T c, determine that the condition 1 is not satisfied; stop performing the following steps; dl5) Count the number of conditions 1;

616) The threshold T2 corresponding to the above number is set through the simulation process and compared with the number counted in step dl5. When the counted number is greater than the threshold T2, it is judged that the judgment condition is satisfied, otherwise it is judged that the judgment is not satisfied. condition.