User scheduling method for orthogonal and non-orthogonal hybrid multiple access mechanism based on spectrum efficiency management

Abstract

The invention discloses a user scheduling method for an orthogonal and non-orthogonal hybrid multiple access mechanism based on spectrum efficiency management. The method comprises the following steps: step 1, a base station collects channel gain information of users in a network; step 2, the base station adopts a Stackelberg game mechanism to make a decision for multi-user hybrid multiple access, so that effective management of spectrum efficiency in the network is achieved; step 3, the base station updates a threshold value of the spectrum efficiency required by the network, and if the actual spectrum efficiency of the network is greater than or equal to the threshold value, the multiple access decision scheduling strategy of the user in the step 2 is not changed; and if the actual spectrum efficiency of the network is smaller than the threshold value, returning to the step 1 and the step 2, and carrying out user scheduling of the hybrid multiple access mechanism again. According to the method, the Stackelberg game method is adopted to effectively manage the spectrum efficiency of the orthogonal and non-orthogonal hybrid multiple access mechanism, the characteristics of the non-orthogonal multiple access technology and the orthogonal multiple access technology are combined, and the method physically conforms to the scene of practical application and can be effectively applied to engineering practice.

Description

Technical Field

[0001] The present invention relates to the technical field of multiple access in wireless communication, and in particular to a user scheduling method oriented to an orthogonal and non-orthogonal hybrid multiple access mechanism based on spectrum efficiency management. Background Art

[0002] In wireless networks, how to improve spectrum efficiency on limited spectrum resources is one of the key contents of wireless network communication research. With the application of non-orthogonal multiple access technology in the network, different users are allocated different powers so that they can share the same subcarrier to achieve simultaneous transmission of superimposed information to multiple users. At the receiving end, the interference signal is deleted through the successive interference cancellation (SIC) technology, so as to achieve the coexistence of multiple users on a single subcarrier and improve the system capacity, thereby significantly improving the spectrum efficiency. Especially in an environment with a large number of users and complex channel conditions, the advantages of NOMA technology are more obvious. However, non-orthogonal multiple access technology dynamically allocates resources according to the needs and channel conditions of different users. For example, for users with good channel quality, less power is allocated; while for users with poor channel quality, more power is allocated to ensure that all users can obtain good communication quality. This makes it impossible for users with better channels to give full play to their channel advantages, thereby reducing the total system throughput to a certain extent. In addition, NOMA technology also has problems such as intra-cluster interference, which makes it possible for users with better channel gain to increase intra-cluster interference in NOMA when they require higher QoS. Therefore, the present invention focuses on network scenarios of orthogonal and non-orthogonal hybrid multiple access mechanisms, conducts in-depth theoretical analysis and application exploration of key user scheduling technologies based on spectrum efficiency management, aiming to provide a unique and efficient solution.

[0003] In future wireless networks, a single multiple access method is not suitable for application scenarios where user QoS requirements change rapidly and user service requirements are diverse, which is not conducive to the robustness of the system. Therefore, how to design a multi-user scheduling method for orthogonal and non-orthogonal hybrid multiple access mechanisms based on different channel gains and requirements of users to achieve effective management of system spectrum efficiency is a difficult problem that needs to be solved urgently. Summary of the invention

[0004] Purpose of the invention: The present invention provides a user scheduling method for orthogonal and non-orthogonal hybrid multiple access mechanisms based on spectrum efficiency management, which improves the flexible selection of multi-user access mechanisms.

[0005] Technical solution: The user scheduling method for orthogonal and non-orthogonal hybrid multiple access mechanisms based on spectrum efficiency management described in the present invention comprises the following steps:

[0006] Step 1: The base station collects channel gain information of users in the network;

[0007] Step 2: The base station uses the Stackelberg game mechanism to make decisions for hybrid multiple access of multiple users, thereby achieving effective management of spectrum efficiency in the network;

[0008] Step 3: The base station updates the network required spectrum efficiency threshold. If the actual network spectrum efficiency is greater than or equal to the threshold, the multiple access decision scheduling strategy of the user in step 2 remains unchanged. If the actual network spectrum efficiency is less than the threshold, return to steps 1 and 2 and perform user scheduling of the hybrid multiple access mechanism again.

[0009] Furthermore, in step 2, in the game, the base station, as the leader of the two parties in the game, sells spectrum efficiency resources, while non-orthogonal multiple access and orthogonal multiple access, as the buyers in the game, followers, obtain benefits by purchasing limited spectrum efficiency.

[0010] Furthermore, the seller utility function in the game model is defined as the revenue obtained by the base station from selling limited spectrum efficiency resources to the hybrid multiple access mode. The seller utility function is expressed as

[0011]

[0012] Furthermore, the utility function of non-orthogonal multiple access as one of the buyers in the game model is defined as the difference between the rate obtained by the user to obtain the base station spectrum efficiency resources and the price paid. The utility function of non-orthogonal multiple access as a buyer is expressed as

[0013]

[0014] Furthermore, the utility function of OFMA as one of the buyers in the game model is defined as the difference between the rate obtained by the user to obtain the spectrum efficiency resources of the base station and the price paid. The utility function of OFMA as a buyer is expressed as

[0015]

[0016] Furthermore, in step 3, the final Stackelberg equilibrium is obtained by the game leaders and followers playing games according to the rules, that is, the optimal unit resource pricing β is obtained by maximizing the utility function representing the interests of the base station and the orthogonal and non-orthogonal multiple access technologies with a mutually competing relationship. * , the buyer takes the seller's optimal price β * Get the optimal power allocation ( and ), the optimal bandwidth of non-orthogonal multiple access and orthogonal multiple access technology ( and ) and optimal user scheduling decision

[0017] Furthermore, in step 3, the base station updates the network required spectrum efficiency threshold value. If the network actual spectrum efficiency is greater than or equal to the threshold value, the user's multiple access decision scheduling strategy obtained by the above Stackelberg game remains unchanged; if the network actual spectrum efficiency is less than the threshold value, it is necessary to re-perform the Stackelberg game for the user scheduling of the hybrid multiple access mechanism.

[0018] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: The present invention adopts the Stackelberg game method to achieve effective management of the spectrum efficiency of orthogonal and non-orthogonal hybrid multiple access mechanisms, combines the characteristics of non-orthogonal multiple access and orthogonal multiple access technologies, physically conforms to the scenarios of real applications and can be effectively applied to engineering practice. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the method flow of the present invention. DETAILED DESCRIPTION

[0020] like Figure 1 As shown, a user scheduling method for orthogonal and non-orthogonal hybrid multiple access mechanisms based on spectrum efficiency management includes the following steps:

[0021] Step 1: The base station collects channel gain information of users in the network;

[0022] Step 2: The base station uses the Stackelberg game mechanism to make decisions for hybrid multiple access of multiple users, thereby achieving effective management of spectrum efficiency in the network;

[0023] Step 3: The base station updates the network required spectrum efficiency threshold. If the actual network spectrum efficiency is greater than or equal to the threshold, the multiple access decision scheduling strategy of the user in step 2 remains unchanged. If the actual network spectrum efficiency is less than the threshold, return to steps 1 and 2 and perform user scheduling of the hybrid multiple access mechanism again.

[0024] In step 2, the Stackelberg game mechanism is to model the user's non-orthogonal and orthogonal hybrid multiple access problems as an economic game model for solution.

[0025] In the game, the base station, as the leader, sells spectrum efficiency resources, while non-orthogonal multiple access and orthogonal multiple access, as the followers, obtain benefits by purchasing limited spectrum efficiency.

[0026] In the game model, the seller utility function is defined as the revenue obtained by the base station from selling limited spectrum efficiency resources to the hybrid multiple access mode. The seller utility function is expressed as

[0027] The utility function of non-orthogonal multiple access as one of the buyers in the game model is defined as the difference between the rate obtained by the user to obtain the spectrum efficiency resources of the base station and the price paid. The utility function of non-orthogonal multiple access as a buyer is expressed as

[0028]

[0029] The utility function of OFMA as one of the buyers in the game model is defined as the difference between the rate obtained by the user to obtain the spectrum efficiency resources of the base station and the price paid. The utility function of OFMA as a buyer is expressed as

[0030]

[0031]

[0032] The seller can dynamically adjust the optimal unit spectrum efficiency resource pricing β according to the minimum spectrum efficiency threshold required in the network * Then, the buyer buys the product based on the seller's optimal price β * Adjust power allocation ( and ), the optimal bandwidth of non-orthogonal multiple access and orthogonal multiple access technology ( and ) and optimal user scheduling decision

[0033] The method of performing the game between hybrid multiple access technologies again in step 3 is only performed when the actual spectrum efficiency of the network is less than the updated spectrum efficiency threshold value.

[0034] Combination Figure 1 As shown, the design scheme of the present invention is further specifically analyzed and described.

[0035] In the wireless network described in the design of the present invention, it is assumed that there are M user terminals defined as Without loss of generality The users to the base station are arranged in descending order of channel gain, i.e. h1>…>hm >…>h M Since there are two kinds of multiple access mechanisms, orthogonal and non-orthogonal, in the wireless network studied by the present invention, it is assumed that the bandwidth width for the non-orthogonal multiple access mechanism is ω1, and the bandwidth width for the orthogonal multiple access mechanism is ω2.

[0036] In the present invention, each user is limited to only select one of the orthogonal and non-orthogonal multiple access mechanisms for data transmission, and α is defined as m ∈{0,1} is a binary indicator variable for user access decision, where α m =1 means user m chooses to access the non-orthogonal multiple access mechanism, otherwise α m =0 indicates that user m selects the orthogonal multiple access mechanism for access.

[0037] Considering that users can choose orthogonal or non-orthogonal multiple access mechanisms for data transmission, each multiple access mechanism hopes to sell its access resources to improve its respective utility. Therefore, in the hybrid multiple access mechanism provided by the present invention, there is a competitive relationship between the orthogonal and non-orthogonal multiple access mechanisms for user access. Steinberg game is a pure strategy non-cooperative sequential game model in economics. According to the priority of actions and the completeness of information mastered, the participants of the game can be divided into leaders and followers. Followers only have partial information and take the lead in action; while leaders act later because they have all the information of followers. Among them, the leader needs to consider the optimal response of followers when setting the game strategy, and followers give their own optimal resource purchase size according to the optimal decision of the leader. In the present invention, since the base station has global information, the base station is used as the leader of the game model, and the orthogonal and non-orthogonal multiple access mechanisms that only have partial information act as followers.

[0038] Let β represent the unit spectrum efficiency price sold by the base station to the multiple access mechanism. Since the purpose of purchasing resources in the game mechanism for orthogonal and non-orthogonal multiple access mechanisms (followers) is to increase the transmission rate of data services, that is,

[0039]

[0040] Where: p 1,m The base station power value purchased for the non-orthogonal multiple access technology is used to send data to user m; N0 is the noise spectral density at the user receiver; is the interference value of NOMA cluster to user m.

[0041] Therefore, the utility function of non-orthogonal multiple access technology as one of the game followers consists of two parts, namely the rate benefit and the price paid for purchasing spectrum efficiency, which is

[0042]

[0043] in: is the spectrum efficiency of the non-orthogonal multiple access mechanism; β is the unit resource pricing, so The revenue generated by base stations selling spectrum efficiency resources to non-orthogonal multiple access mechanisms is also the price paid by the non-orthogonal multiple access mechanisms.

[0044] Similarly, as one of the game followers, the orthogonal multiple access technology pursues rate benefits, that is,

[0045]

[0046] Among them, p 2,m The base station power value purchased for OFTA is used for data transmission to user m; is the number of users using OFMA technology; The bandwidth width obtained by each user in orthogonal multiple access technology.

[0047] As one of the followers of the game, the utility function of the OFA technology consists of two parts: the rate benefit and the price paid for purchasing spectrum efficiency.

[0048]

[0049] in: is the spectrum efficiency of the orthogonal multiple access mechanism, so The revenue generated by selling spectrum efficiency resources to the orthogonal multiple access mechanism for the base station is also the price paid by the orthogonal multiple access mechanism. It is worth noting that if the system adopts orthogonal frequency division multiple access technology, since there will be 50% overlapping bandwidth between two adjacent subcarriers, in the utility function of the above-mentioned orthogonal multiple access technology, it is only necessary to correct the bandwidth occupied by each user according to the orthogonal frequency division multiple access technology, so the present invention is also applicable to orthogonal frequency division multiple access technology.

[0050] As the amount of resources purchased increases, the benefits it obtains also increase, but its cost function will also increase. For orthogonal and non-orthogonal multiple access technologies (followers) in the game model, its goal is to obtain the highest data transmission rate at the lowest cost in the game behavior, that is, to maximize its own utility function.

[0051] For non-orthogonal multiple access technology, there are

[0052] P1.1:

[0053] For orthogonal multiple access technology, there are

[0054] P1.2:

[0055] The seller leader in the game relationship, i.e., the base station, sells resources to the multiple access technology for data transmission to its users, so its objective function is

[0056]

[0057] Since the total downlink power of the base station is limited, there is a constraint at the base station end:

[0058]

[0059] in, The maximum downlink power of the base station.

[0060] Orthogonal multiple access can achieve higher data transmission rates, but its spectrum efficiency is lower; while non-orthogonal multiple access technology can achieve higher spectrum efficiency, but due to the intra-cluster interference within it, users with better channel gain will obtain lower transmission power. Based on the above analysis, users can dynamically adjust and balance the relationship between spectrum efficiency and data transmission rate in the network by selecting different multiple access methods. The purpose of the present invention is to make decisions on orthogonal and non-orthogonal mixed multiple access through the Stackelberg game method, so as to achieve effective management of spectrum efficiency in the network. Therefore, it is necessary to set a minimum threshold for the spectrum efficiency obtained after user scheduling in the network. The constraints are:

[0061]

[0062] Wherein, Ξ is the minimum spectrum efficiency threshold of the network.

[0063] At the same time, the bandwidth used by the network cannot be infinite, so the total bandwidth used by OFMA and NAMA technologies should be less than or equal to the maximum available bandwidth. Right now

[0064]

[0065] In the game, the base station acts as a leader to sell resources and gain profits. Therefore, the seller's goal in selling is to maximize its own utility function while considering constraints. Therefore, for the leader,

[0066]

[0067]

[0068] P1.1, P1.2 and P2 together constitute the Stackelberg game. The final Stackelberg equilibrium can be obtained by the game leaders (base stations) and followers (orthogonal and non-orthogonal multiple access technologies) playing games according to certain rules. That is, the optimal unit resource pricing β is obtained by maximizing the utility functions that represent the interests of the base stations and the orthogonal and non-orthogonal multiple access technologies that have a mutually competitive relationship. * Then, the buyer buys the product based on the seller's optimal price β * Get the optimal power allocation ( and ), the optimal bandwidth of non-orthogonal multiple access and orthogonal multiple access technology ( and ) and optimal user scheduling decision

[0069] Subsequently, the base station updates the network required spectrum efficiency threshold. If the actual network spectrum efficiency is greater than or equal to the threshold, the multiple access decision scheduling strategy of the user obtained by the above Stackelberg game remains unchanged. If the actual network spectrum efficiency is less than the threshold, it is necessary to re-perform the Stackelberg game for the user scheduling of the hybrid multiple access mechanism.

Claims

1. A user scheduling method for orthogonal and non-orthogonal hybrid multiple access mechanisms based on spectrum efficiency management, characterized in that: The steps include: Step 1: The base station collects channel gain information of users in the network; Step 2: The base station uses the Stackelberg game mechanism to make decisions for hybrid multiple access of multiple users, thereby achieving effective management of spectrum efficiency in the network; Step 3: The base station updates the network required spectrum efficiency threshold. If the actual network spectrum efficiency is greater than or equal to the threshold, the multiple access decision scheduling strategy of the user in step 2 remains unchanged. If the actual network spectrum efficiency is less than the threshold, return to steps 1 and 2 and perform user scheduling of the hybrid multiple access mechanism again.

2. The user scheduling method for orthogonal and non-orthogonal hybrid multiple access mechanisms based on spectrum efficiency management as claimed in claim 1, characterized in that: In step 2, in the game, the base station, as the leader of the two parties in the game, sells spectrum efficiency resources, while non-orthogonal multiple access and orthogonal multiple access, as the buyers in the game, followers, obtain benefits by purchasing limited spectrum efficiency.

3. The user scheduling method for orthogonal and non-orthogonal hybrid multiple access mechanisms based on spectrum efficiency management as claimed in claim 1, characterized in that: In the game model, the seller utility function is defined as the revenue obtained by the base station from selling limited spectrum efficiency resources to the hybrid multiple access mode. The seller utility function is expressed as Where: p 1,m The base station power value purchased for the non-orthogonal multiple access technology is used to send data to user m; N , is the noise spectral density at the user receiver; is the interference value of NOMA cluster to user m, p 1,m The base station power value purchased for OFTA is used for data transmission to user m; is the number of users using OFMA technology; The bandwidth width obtained by each user in orthogonal multiple access technology.

4. The user scheduling method for orthogonal and non-orthogonal hybrid multiple access mechanisms based on spectrum efficiency management as claimed in claim 1, characterized in that: The utility function of non-orthogonal multiple access as one of the buyers in the game model is defined as the difference between the rate obtained by the user to obtain the spectrum efficiency resources of the base station and the price paid. The utility function of non-orthogonal multiple access as a buyer is expressed as 5. The user scheduling method for orthogonal and non-orthogonal hybrid multiple access mechanisms based on spectrum efficiency management as claimed in claim 1, characterized in that: The utility function of OFMA as one of the buyers in the game model is defined as the difference between the rate obtained by the user to obtain the spectrum efficiency resources of the base station and the price paid. The utility function of OFMA as a buyer is expressed as 6. The user scheduling method for orthogonal and non-orthogonal hybrid multiple access mechanisms based on spectrum efficiency management as claimed in claim 1, characterized in that: In step 3, the final Stackelberg equilibrium is obtained by the game leaders and followers playing games according to the rules, that is, the optimal unit resource pricing β is obtained by maximizing the utility function representing the interests of the base station and the orthogonal and non-orthogonal multiple access technologies with a mutually competing relationship. * , the buyer takes the seller's optimal price β * Get the optimal power allocation ( and ), the optimal bandwidth of non-orthogonal multiple access and orthogonal multiple access technology ( and ) and optimal user scheduling decision 7. The user scheduling method for orthogonal and non-orthogonal hybrid multiple access mechanisms based on spectrum efficiency management as claimed in claim 1, characterized in that: In step 3, the base station updates the network required spectrum efficiency threshold. If the actual network spectrum efficiency is greater than or equal to the threshold, the multiple access decision scheduling strategy of the user obtained by the above Stackelberg game remains unchanged; if the actual network spectrum efficiency is less than the threshold, it is necessary to re-perform the Stackelberg game for the user scheduling of the hybrid multiple access mechanism.

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