Method for connecting a device with the aid of an unlicensed band

Abstract

The application discloses a connection method of a device under the assistance of a license-exempt frequency band, and comprises the following steps: detecting the use state of each license-exempt channel; allocating the currently idle license-exempt channel to a base station user and estimating the available time of the license-exempt channel; screening the base station user to obtain a base station user that finally transmits data; and optimizing the energy consumption of the screened base station user, so as to improve the connection transmission quality of the base station user. The application can reasonably allocate the power of the user on the licensed channel and the license-exempt channel, ensure that each user can reach a basic transmission rate on the basis of the spectrum resource and power constraints and coexistence with Wi-Fi users, improve the transmission quality of the user, and ensure the fairness of the user in the system.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to a method for connecting devices using unlicensed frequency bands. Background Technology

[0002] In urban cellular networks, the scarcity of licensed spectrum has become a major bottleneck for improving network speeds. However, unlicensed channels under Wi-Fi suffer from low spectral efficiency due to a lack of efficient resource management systems. In contrast, New Radio (NR) offers much more efficient resource management. Therefore, considering the use of unlicensed frequency bands (NR-U) is a primary method to address spectrum resource shortages. To alleviate the shortage of licensed spectrum resources, Licensed Assisted Access (LAA) has been introduced to allow base station users to share unlicensed channels with Wi-Fi users.

[0003] However, the impact on Wi-Fi users should also be considered when base station users utilize unlicensed frequency bands. Intuitively, the more unlicensed channels a base station user uses, the higher the spectral efficiency on those channels. However, this leads to a decrease in performance for Wi-Fi users. Therefore, in NR-U systems, there is an inherent trade-off between spectral efficiency and the impact on Wi-Fi users. That is, when base station users use unlicensed frequency bands, they may "collide" with Wi-Fi users, and the channel's transmission rate may be affected. Summary of the Invention

[0004] The purpose of this invention is to provide a connection method for devices using unlicensed frequency bands. This invention can reduce the probability of data packet collisions between base station users and Wi-Fi users, while also ensuring the transmission rate of the unlicensed channel and improving transmission quality.

[0005] The technical solution of the present invention: a method for connecting devices under unlicensed frequency band assistance, comprising the following steps:

[0006] S1: Detect the usage status of each unlicensed channel;

[0007] S2: Allocate the currently available unlicensed channels to base station users and estimate the available time of the unlicensed channels;

[0008] S3: Filter the base station users to obtain the final base station users for data transmission;

[0009] S4: Optimize the energy consumption of the selected base station users to improve the connection and transmission quality of the base station users.

[0010] In the aforementioned connection method for devices assisted by unlicensed frequency bands, the method for screening base station users is a binary search method, which includes the following steps:

[0011] S31.1: Estimate the channel gain for each base station user;

[0012] S31.2: Sort base station users from high to low according to channel gain to generate user sequence;

[0013] S31.3: Set feasibility conditions;

[0014] S31.4: Perform a cyclical filtering in the user sequence to select all base station users that meet the feasibility conditions.

[0015] In the aforementioned method for connecting devices using unlicensed frequency band assistance, the cyclic screening includes the following steps:

[0016] S31.4.1: Let the number of users that can be connected be the middle number of users in the total number of user sequences. Determine whether the middle number of users meets the feasibility condition: If the first half of the users in the user sequence meets the feasibility condition, the maximum number of users remains unchanged, and half of the users are taken as the minimum number of users to generate a new user sequence; If the middle number of users does not meet the feasibility condition, the minimum number of users remains unchanged, and the middle number of users is transformed into the maximum number of users to generate a new user sequence.

[0017] S31.4.2: Repeat S31.4.1 in the new user sequence until the difference between the maximum and minimum values ​​in the final generated user sequence is less than or equal to 1. Determine whether the number of base station users in the middle meets the feasibility condition. If it does, then in the user sequence of S31.2, take out all the base station users at the beginning of the previous sequence with that number of users. If it does not meet the condition, then in the user sequence of S31.2, take out all the base station users at the beginning with that number of users minus 1 as the endpoint.

[0018] In the aforementioned connection method for devices assisted by unlicensed frequency bands, the method for screening base station users is a genetic algorithm, which includes the following steps:

[0019] S32.1: Set feasibility conditions;

[0020] S32.2: Randomly initialize the number of base station users with connections, and determine whether the feasibility condition is met under the current number of connections. If it is met, then treat the number of connections as a possibility of connection.

[0021] S32.3: Repeat S32.2, list all possible connections and calculate the fitness value for each possibility;

[0022] S32.4: Sort all possibilities according to their fitness values ​​to obtain a set of feasible solutions;

[0023] S32.5: Perform crossover or mutation processing on the feasible solution set to generate a new feasible solution set and calculate the fitness value of all possibilities in the new feasible solution set;

[0024] S32.6: Sort all possibilities in the new feasible solution set according to fitness value, repeat S32.5 in the new feasible solution set, and record the number of iterations;

[0025] S32.7: Stop the loop when the number of iterations reaches the preset number of iterations, and obtain the final set of feasible solutions.

[0026] In the aforementioned method for connecting devices using unlicensed frequency band assistance, the cross-connection process is as follows:

[0027] Two sets of possibilities are randomly selected from the feasible solution set and cut into two segments at the same position. The segments of the two sets of possibilities are then swapped to form a new feasible solution set.

[0028] In the aforementioned method for connecting devices using unlicensed frequency band assistance, the mutation processing is as follows:

[0029] In the feasible solution set, the user's connection state in each set of possibilities is inverted to generate a new feasible solution set.

[0030] In the aforementioned method for connecting devices with unlicensed frequency band assistance, the energy consumption optimization method includes the Lagrange multiplier method.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] In this invention, before allocating unlicensed channels, the usage status of each unlicensed channel is detected, and idle unlicensed channels are allocated to base station users, thereby reducing the probability of data packet collisions between base station users and Wi-Fi users. After allocating unlicensed channels, base station users need to be screened to maximize the number of connectable base station users. Then, energy consumption optimization is performed on base station users to reduce the energy consumption of unlicensed channels and improve their transmission rate. In summary, this invention can rationally allocate power for users on licensed and unlicensed channels, ensuring that each user can reach a basic transmission rate while considering spectrum resources and power constraints and coexisting with Wi-Fi users, thus improving user transmission quality and ensuring fairness for users in the system. Attached Figure Description

[0033] Figure 1 This is a flowchart of the connection method in this invention;

[0034] Figure 2 This is a schematic diagram of the interaction between the base station and the user equipment of the present invention;

[0035] Figure 3 This is a schematic diagram of the user equipment in this invention;

[0036] Figure 4 This is a schematic diagram of the base station structure in this invention. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0038] Example: Connection method of devices under unlicensed frequency band assistance, as shown in the appendix. Figure 1 As shown, it includes the following steps:

[0039] S1: Detect the usage status of each unlicensed channel. Because the system uses a DCF mechanism during transmission, Wi-Fi users transmit on unlicensed channels, while NR-U users transmit data through licensed channels, unlicensed channels, and NR-U. When base station users upload data, they may occupy unlicensed channels, potentially causing signal collisions with Wi-Fi users. Therefore, when allocating unlicensed channels to base station users, it is necessary to check the usage status of each unlicensed channel beforehand.

[0040] S2: Allocate currently available unlicensed channels to base station users and estimate the availability time of the unlicensed channels. (See attached...) Figure 2 As shown, since there is competition between base station users and Wi-Fi users accessing the base station through the unlicensed channel, the base station detects whether the unlicensed channel is idle and allocates the idle channel to base station users, thus enabling the sharing of the unlicensed channel in the Wi-Fi system. While sharing the unlicensed channel, it is necessary to obtain the access probability of the Wi-Fi user on the corresponding unlicensed channel, the access probability of the base station user on the corresponding unlicensed channel, the probability of data packet collision for the Wi-Fi user, and the probability of data packet collision when the base station user sends data packets on the corresponding unlicensed channel. Based on these probabilities, the maximum available time coefficient α for the base station user on the unlicensed channel is derived, and the available time for the base station user on the unlicensed channel is estimated based on the maximum available time coefficient α.

[0041] In this embodiment, as shown in the appendix Figure 3 and attached Figure 4As shown, the user's equipment includes a transmitting unit, a receiving unit, and a processing unit, while the base station includes a transmitting unit, a receiving unit, a processing unit, and an unlicensed frequency band listening unit. The base station allocates unlicensed and licensed channels to users. On licensed channels, the channel is divided into N sub-channels of equal bandwidth. On unlicensed channels, the number of unlicensed channels is set to be the same as the number of Wi-Fi nodes. The base station allocates available time for users on unlicensed channels. Therefore, for users, their transmission rate consists of two parts: the channel transmission rate on the allocated licensed channel and the transmission rate on each unlicensed channel. If the collision probability does not exceed a predefined collision threshold, fair coexistence between base station users and Wi-Fi users can be guaranteed. Since the collision probability is related to the channel access probability of base station users, and the channel access probability is determined by the backoff window size w, the collision probability can be controlled by adjusting w, thereby controlling the available unlicensed time.

[0042] S3: To maximize the number of connected base station users while controlling their energy consumption, an optimization objective was designed. The optimization objective is: Where I represents the total number of connected users, P represents the total energy consumption of the connected users, and p (L) The power allocated to a user on the licensed channel, p (U) Power allocated to users on unlicensed channels The bandwidth factor allocated to users on unlicensed channels. Let w be the time coefficient available for a user in the unlicensed channel, and w be the backoff window size. To achieve the above optimization objective, it is first necessary to filter the base station users to obtain the final base station users for data transmission. In this embodiment, the total number of base station users is I, and the set of base station users can be represented as i = {1, 2, ..., I}. The method for filtering base station users is either binary search or a genetic algorithm. The binary search method includes the following steps:

[0043] S31.1: Estimate the channel gain for each base station user;

[0044] S31.2: Sort base station users from largest to smallest according to channel gain, generate user sequence, and initialize I. min =0, I max =I, where I min The minimum number of users, I max This represents the maximum number of users.

[0045] S31.3: Set feasibility conditions, the feasibility conditions are as follows:

[0046] S31.4: Perform a cyclic filtering in the user sequence to select all base station users that meet the feasibility conditions; the number of cycles is initialized to j=1, M(j)=I. max The cyclical filtering includes the following steps:

[0047] S31.4.1: Let the number of users that can be connected be the middle number of users extracted from the user sequence, where the middle number of users is... Determine if the median number of users meets the feasibility condition: If the median number of users does not meet the feasibility condition, the minimum number of users remains unchanged, and the median number of users is taken as the maximum number of users, thus obtaining I. max =M(j), generate a new user sequence; if the first half of the users in the user sequence meet the feasibility conditions, then the maximum number of users remains unchanged, and the median number of users is taken as the minimum number of users, that is, I. min =M(j), generating a new user sequence;

[0048] S31.4.2: Repeat S31.4.1 in the new user sequence until the difference between the maximum and minimum values ​​in the final generated user sequence is less than or equal to 1. Determine whether the number of base station users in the middle meets the feasibility condition. If it does, then in the user sequence of S31.2, take out all the base station users at the beginning of the previous sequence with that number of users. If it does not meet the condition, then in the user sequence of S31.2, take out all the base station users at the beginning with that number of users minus 1 as the endpoint.

[0049] Genetic algorithms include the following steps:

[0050] S32.1: Set feasibility conditions. In the genetic algorithm, the feasibility conditions are the same as those in the bisection method, both being...

[0051] S32.2: Randomly initialize the number of base station users with connections, and determine whether the feasibility condition is met under the current number of connections. If it is met, then treat the number of connections as a possibility of connection.

[0052] S32.3: Repeat S32.2, list all possible connections and calculate the fitness value for each possibility;

[0053] S32.4: Sort all possibilities according to their fitness values ​​to obtain a set of feasible solutions;

[0054] S32.5: Perform crossover or mutation processing on the feasible solution set to generate a new feasible solution set and calculate the fitness value of all possibilities in the new feasible solution set; the crossover processing is: randomly select two sets of possibilities in the feasible solution set, cut them into two segments at the same position, and exchange the segments of the two sets of possibilities to form a new feasible solution set. The mutation processing is: invert the user's connection state in each set of possibilities in the feasible solution set to generate a new feasible solution set;

[0055] S32.6: Sort all possibilities in the new feasible solution set according to fitness value, repeat S32.5 in the new feasible solution set, and record the number of iterations;

[0056] S32.7: Stop the loop when the number of iterations reaches the preset number of iterations, and obtain the final set of feasible solutions.

[0057] In this embodiment, the connection status of each base station user is randomly initialized, and the connection status of the j-th base station user is set to I. j =1, and I is set to I if the user at the j-th base station is not connected. j =0, substitute the initial base station user connection status into the feasibility conditions, and determine if there is a feasible solution. If there is a feasible solution, it will be considered as a possible connection. Specifically, in this embodiment, the initial total number of users is set to 20. Finally, 10 sets of feasible solutions are found and their fitness values ​​are calculated. Among them SU i The feasible solution set for the base station user is grouped. Within each group of possible solutions, a crossover or mutation process is selected based on the fitness value. Two feasible solutions are randomly selected and compared; the one with the larger fitness value is subjected to crossover or mutation. Crossover involves randomly splitting the two parent groups of possibilities into two segments at the same position, swapping the segments to generate two new child possibilities. Mutation involves randomly inverting any 0s or 1s in each possibility group to generate a new child possibility, which helps prevent the algorithm from getting trapped in local optima to some extent. After crossover or mutation, the parent possibilities and the newly generated child possibilities are sorted by fitness value. The top 10 possibilities advance to the next iteration, and the largest feasible solution and its fitness value are identified in this iteration. The iteration stops when the preset number of iterations is reached.

[0058] S4: When addressing feasibility issues, each user connected to the base station will transmit at maximum energy consumption to ensure that the basic rate requirements are met as much as possible, thus enabling transmission and interaction with the base station. Next, energy consumption optimization needs to be performed on the selected base station users to reduce the energy consumption of their connection transmission. The energy consumption optimization method includes the Lagrange multiplier method.

[0059] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the scope of the claims of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for connecting devices under unlicensed frequency band assistance, characterized in that: Includes the following steps: S1: Detect the usage status of each unlicensed channel; S2: Allocate the currently available unlicensed channels to base station users and estimate the available time of the unlicensed channels; S3: Filter base station users to obtain the final base station users for data transmission; maximize the number of connected base station users while controlling the energy consumption of base station users; S4: Optimize the energy consumption of the selected base station users to improve the connection and transmission quality of the base station users; The method for filtering base station users is a binary search, which includes the following steps: S31.1: Estimate the channel gain for each base station user; S31.2: Sort base station users from high to low according to channel gain to generate user sequence; S31.3: Set feasibility conditions; S31.4: Perform a cyclical filtering in the user sequence to filter out all base station users that meet the feasibility conditions; The cyclical filtering includes the following steps: S31.4.1: Let the number of users that can be connected be the middle number of users in the total number of user sequences. Determine whether the middle number of users meets the feasibility condition: If the first half of the users in the user sequence meets the feasibility condition, the maximum number of users remains unchanged, and half of the users are taken as the minimum number of users to generate a new user sequence; If the middle number of users does not meet the feasibility condition, the minimum number of users remains unchanged, and the middle number of users is transformed into the maximum number of users to generate a new user sequence. S31.4.2: Repeat S31.4.1 in the new user sequence until the difference between the maximum and minimum values ​​in the final generated user sequence is less than or equal to 1. Determine whether the intermediate number of base station users meets the feasibility condition. If it does, then in the user sequence of S31.2, extract all the base station users at the beginning of the previous sequence based on this intermediate number. If it does not meet the condition, then in the user sequence of S31.2, extract all the base station users at the beginning of the previous sequence based on this intermediate number minus 1.

2. The connection method for devices under unlicensed frequency band assistance according to claim 1, characterized in that: The method for selecting base station users is a genetic algorithm, which includes the following steps: S32.1: Set feasibility conditions; S32.2: Randomly initialize the number of base station users with connections, and determine whether the feasibility condition is met under the current number of connections. If it is met, then treat the number of connections as a possibility of connection. S32.3: Repeat S32.2, list all possible connections and calculate the fitness value for each possibility; S32.4: Sort all possibilities according to their fitness values ​​to obtain a set of feasible solutions; S32.5: Perform crossover or mutation processing on the feasible solution set to generate a new feasible solution set and calculate the fitness value of all possibilities in the new feasible solution set; S32.6: Sort all possibilities in the new feasible solution set according to fitness value, repeat S32.5 in the new feasible solution set, and record the number of iterations; S32.7: Stop the loop when the number of iterations reaches the preset number of iterations, and obtain the final set of feasible solutions.

3. The connection method for devices under unlicensed frequency band assistance according to claim 2, characterized in that: The cross-processing is as follows: Two sets of possibilities are randomly selected from the feasible solution set and cut into two segments at the same position. The segments of the two sets of possibilities are then swapped to form a new feasible solution set.

4. The connection method for devices assisted by unlicensed frequency bands according to claim 2, characterized in that: The mutation process is as follows: In the feasible solution set, the user's connection state in each set of possibilities is inverted to generate a new feasible solution set.

5. The connection method for devices under unlicensed frequency band assistance according to claim 1, characterized in that: The energy consumption optimization method includes the Lagrange multiplier method.

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