A communication interference suppression method based on cache forwarding

Abstract

The present invention discloses a communication interference suppression method based on cache forwarding, which belongs to the field of wireless communication; specifically: first, for a communication scenario including n base stations and m users, at least two mutually interfering users are distributed in the same antenna direction of at least one base station, and each user is judged, a base station with a maximum downlink transmission rate is selected, and the current user is scheduled to communicate with the base station. After scheduling, the original user on the base station is interfered, and the original user is continued to be judged, and the base station with a maximum downlink transmission rate is selected to schedule the original user. The above scheduling is repeated over and over again, so that each user communicates with the base station that reaches the respective maximum transmission rate, ensuring that the interference in each area is as small as possible and the frequency occupied area is average. The present invention reduces the interference of terminal users and improves the communication quality through cache scheduling.

Description

Technical Field

[0001] The invention belongs to the field of wireless communications, and in particular is a communication interference suppression method based on cache forwarding. Background Art

[0002] Communication systems are widely deployed to provide various types of communications to multiple users, such as voice, data or multimedia services; with the rise of short videos, there are higher requirements for communication quality and efficiency.

[0003] Inter-cell interference is an inherent problem in communication systems, which seriously affects system performance. The reason for this is that users using the same frequency resources in each cell will interfere with each other. When base stations BS1 and BS2 are service base stations for mobile terminals MS1 and MS2 respectively, it is assumed that the subcarrier set allocated by base station BS1 to terminal MS1 for uplink transmission is SC1, and the subcarrier set allocated by base station BS2 to terminal MS2 for uplink transmission is SC2, and the intersection of the two subcarriers SC1 and SC2 is SC. If SC is not an empty set, when base station BS2 receives the uplink signal sent by terminal MS2, the subcarriers in the set SC will simultaneously receive the wireless signal sent by terminal MS1. For terminal MS2 and base station BS2, these signals from terminal MS1 are interference signals.

[0004] Similarly, the downlink will also encounter similar interference problems as the uplink; if the interference between cells is serious, it will directly affect the system's coverage capability and system capacity, especially for users at the edge of the cell, which will directly cause them to frequently drop out of the network or be unable to access the network.

[0005] Reducing inter-cell interference is an important goal of cellular system design. From the existing research results and research projects of various standardization organizations, such as 3GPP's Long Term Evolution (LTE), IEEE's 802.16m, and 3GPP2's Enhanced Mobile Broadband (UMB), the inter-cell interference control technologies include the following three categories:

[0006] 1. Interference randomization technology

[0007] Interference randomization is a commonly used technology that reduces inter-cell interference by whitening the interference of adjacent cells. Its main advantages are: it does not affect the complexity of scheduling and receiving processing at the receiving end, but when the system is fully loaded, the improvement of system performance by interference randomization technology is limited; the representative technologies of interference randomization are base station-based scrambling codes and various frequency hopping technologies.

[0008] 2. Interference coordination technology

[0009] Interference coordination technology is mainly to effectively coordinate channel resources and their power in the spatial, temporal and frequency domains within multiple cells, thereby reducing interference between adjacent cells. Its main technologies include fractional frequency reuse (FFR), multi-base multiple input and output (MIMO) and power control technology.

[0010] 3. Interference cancellation technology

[0011] Interference cancellation technology is to decode and copy the signal of the interfering cell, and then subtract the interference signal from the cell from the received signal. The advantage is that there is no restriction on the use of cell frequency resources; but its limitation is that the target cell must know the pilot structure of the interfering cell in order to perform channel estimation on the interference source. Therefore, the signaling overhead and implementation complexity of interference cancellation technology are relatively high.

[0012] In order to ensure communication quality and enhance user experience, interference is reduced as much as possible during communication. Traditionally, the criterion for a terminal to access a base station or switch to another base station is the signal-to-noise ratio, or the criterion for a terminal to access multiple base stations is the signal-to-noise ratio. There are also access or switching criteria based on delay time, etc. This assumes that the information content cannot be changed on one or a group of base stations.

[0013] In fact, the 5G era has ushered in edge computing MEC technology, which has a large cache and cache forwarding and scheduling capabilities. For the content to be sent, it can be sent to different antennas of different base stations.

[0014] In real life, a terminal is often located in the middle of multiple base stations and can communicate with multiple base stations at the same time. Communication systems usually choose base stations with better signal-to-noise ratios to communicate with them. There are also technologies for joint communication of multiple base stations, such as COMP technology. In actual networking, the layer where multiple base stations access terminals is called the access layer, and multiple access layers concentrate information, which is called the aggregation layer. The base station of the wireless communication system contains the radio frequency part, which is called AAU in the 5G era, and includes remote units, DUs, core units CUs and other parts. Currently, there are no measures for the situation where multiple devices are in the same antenna direction in various methods to reduce interference. Summary of the invention

[0015] In view of the problem of interference caused by two terminals in the same antenna direction, the present invention proposes a communication interference suppression method based on cache forwarding, which performs appropriate scheduling by judging the communication conditions so as to reduce interference to user equipment.

[0016] The communication interference suppression method based on cache forwarding has the following specific steps:

[0017] First, in a communication scenario including n base stations and m users, there are at least two users that interfere with each other distributed in the same antenna direction of at least one base station. By continuously scheduling each user, each user communicates with another different base station respectively, so as to reduce interference to other users.

[0018] There are two users u1 and u2 that interfere with each other distributed in the same antenna direction of base station A. First, select user u1 for scheduling and determine whether there is a base station B that meets the conditions. If so, user u1 will communicate with it. Otherwise, user u1 remains at the original base station A and user u2 is selected for scheduling. If it is determined that there is a base station C that meets the conditions, user u2 will communicate with it. Otherwise, both users u1 and u2 remain stationary and continue to communicate with the original base station A.

[0019] The above judgment process is also applicable when there are three or more users interfering with each other distributed in the same antenna direction of the base station;

[0020] The specific process of selecting a base station that meets the conditions through scheduling is as follows:

[0021] For user u1, count the base stations that communicate with user u1 at the same time, and determine whether there are other users in the antenna direction of each base station;

[0022] When there is only one base station communication antenna with no other users among the base stations communicating with user u1, user u1 directly selects this base station as the optimal base station; if there are multiple base stations with no other users in the communication antenna direction, the maximum downlink transmission rate is calculated and the base station with the highest speed is selected for data transmission;

[0023] Maximize the total downlink transmission rate of the system C max The calculation formula is:

[0024]

[0025] Where n is the number of base stations in the system; m is the number of users in the system; B ij is the bandwidth of the downlink communication link between the i-th base station and the j-th user, and satisfies B i is the total bandwidth that can be allocated to the i-th base station;

[0026] P ij is the received power of the downlink communication link between the i-th base station and the j-th user; P ij ≥0, j;

[0027] σ kj The interference power received by the jth user from other kth users; σ kj≥0,

[0028] N j is the link noise power received by the jth user; N j ≥0,

[0029] Otherwise, when there are other users on the communication antennas of each base station communicating with user u1, traverse each base station to find the base station B with the maximum downlink transmission rate, and schedule user u1 to communicate with it;

[0030] Finally, when user u1 arrives at base station B through scheduling and interferes with the original user u3 on base station B, it continues to repeatedly determine whether u3 can communicate with other qualified base stations D through scheduling, and repeats the above scheduling so that each user communicates with the base station that reaches its maximum transmission rate, ensuring that the interference in each area is as small as possible and the frequency occupancy area is average.

[0031] The advantages of the present invention are:

[0032] 1) A communication interference suppression method based on cache forwarding can reduce interference to terminal users and improve communication quality.

[0033] 2) A communication interference suppression method based on cache forwarding, based on a directional antenna, can suppress interference between two terminals that originally interfere with each other in the same antenna direction through cache scheduling, thereby improving communication quality.

[0034] 3) A communication interference suppression method based on cache forwarding. When there are multiple terminal users in the same antenna direction, the interference reduction and communication resource fairness are comprehensively considered, and the content to be sent is appropriately scheduled to different antennas of different base stations, so that the interference in each area is as small as possible, the frequency occupancy area is averaged, and the fairness of communication resources is guaranteed.

[0035] 4) A communication interference suppression method based on cache forwarding. When the probability distribution of communication demand is known, the reserved spectrum resources in each area are not evenly distributed, but distributed according to the probability distribution of communication demand. The fairness of communication resources can be ensured by scheduling the content to be sent to the antenna of the base station with richer spectrum resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A flow chart of a communication interference suppression method based on cache forwarding according to the present invention;

[0037] Figure 2 This is an example before the improvement of interference suppression under the directional antenna of the present invention;

[0038] Figure 3This is an improved example of interference suppression under the directional antenna of the present invention;

[0039] Figure 4 This is an example before the improvement of the communication buffer scheduling based on the radio wave interference intensity area criterion of the present invention;

[0040] Figure 5 This is an example of the improved communication cache scheduling based on the radio wave interference intensity area criterion of the present invention;

[0041] Figure 6 This is an example of the communication cache scheduling before improvement based on actual needs of the present invention;

[0042] Figure 7 This is an example of the improved communication cache scheduling based on actual needs of the present invention DETAILED DESCRIPTION

[0043] The specific implementation method of the present invention is further described in detail below in conjunction with the accompanying drawings.

[0044] Considering the interference problem between different users in the same antenna direction, the present invention proposes a communication interference suppression method based on cache forwarding. When different users are in the same antenna direction, the link noise power Nj will increase significantly and the downlink transmission rate will decrease significantly. For the current user u1, traverse the base stations in the system, and by judging the communication conditions, obtain the base station that can achieve the maximum downlink transmission rate, schedule user u1 to communicate with it, and reduce the interference between the current user and other users in the same antenna direction.

[0045] The communication interference suppression method based on cache forwarding is as follows: Figure 1 As shown, the specific steps are as follows:

[0046] First, in a communication scenario including n base stations and m users, there are at least two users that interfere with each other distributed in the same antenna direction of at least one base station. By continuously scheduling each user, each user communicates with another different base station respectively, so as to reduce interference to other users.

[0047] There are two users u1 and u2 that interfere with each other distributed in the same antenna direction of base station A. First, select user u1 for scheduling and determine whether there is a base station B that meets the conditions. If so, user u1 will communicate with it. Otherwise, user u1 remains at the original base station A and user u2 is selected for scheduling. If it is determined that there is a base station C that meets the conditions, user u2 will communicate with it. Otherwise, both users u1 and u2 remain stationary and continue to communicate with the original base station A.

[0048] The above judgment process is also applicable when there are three or more users interfering with each other distributed in the same antenna direction of the base station;

[0049] The specific process of selecting a base station that meets the conditions through scheduling is as follows:

[0050] For user u1, count the base stations that communicate with user u1 at the same time, and determine whether there are other users in the antenna direction of each base station;

[0051] When there is only one base station communication antenna with no other users among the base stations communicating with user u1, user u1 directly selects this base station as the optimal base station; if there are multiple base stations with no other users in the communication antenna direction, the maximum downlink transmission rate is calculated and the base station with the highest speed is selected for data transmission;

[0052] Maximize the total downlink transmission rate of the system C max The calculation formula is:

[0053]

[0054] Where n is the number of base stations in the system; m is the number of users in the system; B ij is the bandwidth of the downlink communication link between the i-th base station and the j-th user, and satisfies B i is the total bandwidth that can be allocated to the i-th base station;

[0055] P ij is the received power of the downlink communication link between the i-th base station and the j-th user; P ij ≥0, j;

[0056] σ kj The interference power received by the jth user from other kth users; σ kj ≥0,

[0057] N j is the link noise power received by the jth user; N j ≥0,

[0058] Otherwise, when there are other users on the communication antennas of each base station communicating with user u1, traverse each base station to find the base station B with the maximum downlink transmission rate, and schedule user u1 to communicate with it;

[0059] Finally, when user u1 arrives at base station B through scheduling and interferes with the original user u3 on base station B, it continues to repeatedly determine whether u3 can communicate with other qualified base stations D through scheduling, and repeats the above scheduling so that each user communicates with the base station that reaches its maximum transmission rate, ensuring that the interference in each area is as small as possible and the frequency occupancy area is average.

[0060] like Figure 2 As shown, it shows the situation where there are two terminal users in the same antenna direction. It is assumed that the first user UE1 is between the first antenna direction D1 of the first base station gNB1 and the second antenna direction D2 of the second base station gNB2. At this time, in terms of the received signal-to-noise ratio, it is the same whether it is sent from the first antenna direction of the first base station or the second antenna direction of the second base station. However, there is a second user UE2 in the main lobe of the first antenna beamforming of the first base station. If it is sent from the first direction of the first base station, the second user will be interfered. Therefore, it is better for the second base station to send the sent content, so as to reduce the interference to UE2.

[0061] Figure 3 That is, after the improvement of the present application, the first user UE1 communicates with the second base station; by judging the initial parameters, the number of terminals in the antenna direction between the base station and the user UE1, and whether the user UE1 can communicate with other base stations, and whether there are other terminals in the antenna direction of other base stations that the user UE1 can communicate with, the base station participating in this data transmission is selected for scheduling, and the content is sent from the optimal base station, thereby suppressing interference.

[0062] When there is interference between multiple base stations and multiple directional antenna groups, such as Figure 4 As shown in the figure, the communication status at this moment determines that the spectrum occupied in some areas is larger in terms of frequency width and power, while in some areas it is smaller. In areas with tight spectrum resources, there will be fewer communication resources, and it will be difficult for new users to obtain more communication resources. On the contrary, in areas with abundant frequency resources, it is easy for new users to obtain more communication resources. In addition, when there are multiple terminal users in the same antenna direction, comprehensive consideration is given to reducing interference and fairness of communication resources, and the content being sent is appropriately scheduled to different antennas of different base stations, so that the interference in each area is as small as possible, the frequency occupation area is average, and the fairness of communication resources is guaranteed.

[0063] like Figure 5 The figure shows the improved communication cache scheduling based on the radio wave interference intensity area criterion. According to different communication resources and the initial parameters, the number of terminals in the antenna direction between the base station and the user, whether the user can communicate with other base stations, and whether there are other terminals in the antenna direction of other base stations that the user can communicate with. The base station participating in the data transmission is selected, and the scheduling is performed to send the content from the optimal base station, thereby suppressing interference.

[0064] Communication cache scheduling based on actual needs, such as Figure 6 and Figure 7As shown in the figure, when the demand probability distribution diagram is known, the target distribution is not average, but the frequency occupancy of each area meets the demand statistics. That is, more spectrum resources are reserved in areas with high demand for communication resources. In actual situations, when there are multiple terminal users in the same antenna direction, comprehensive consideration is given to reducing interference and fairness of communication resources, and the content being sent is appropriately scheduled to different antennas of different base stations, so that the interference in each area is as small as possible, the frequency occupancy area is average, and the fairness of communication resources is guaranteed. Figure 6 In case of interference, Figure 7 This is the improved situation.

[0065] The present invention enables two terminals originally in the same antenna direction to send content by selecting a qualified base station through scheduling, so that the two terminals communicate with two different base stations respectively. By scheduling and balancing communication resources, communication pressure is relieved, interference of terminal users is reduced, and communication efficiency and quality are improved.

[0066] When spectrum resources in different areas are uneven, by scheduling the content to be sent to the antennas of base stations with more abundant spectrum resources, the frequency occupancy rate in each area can be averaged, ensuring the fairness of communication resources.

[0067] When the probability distribution of communication demand is known, the reserved spectrum resources in each area are not evenly distributed, but are distributed according to the probability distribution of communication demand. The fairness of communication resources can be ensured by scheduling the content to be sent to the antennas of base stations with richer spectrum resources.

Claims

1. A communication interference suppression method based on cache forwarding, characterized in that: The specific steps are as follows: First, in a communication scenario including n base stations and m users, at least two users interfering with each other are distributed in the same antenna direction of at least one base station. For the current user causing interference, the downlink transmission rate between the user and each base station is calculated, and the base station with the maximum downlink transmission rate is selected to communicate with the user. The specific process of scheduling users to select the base station with the maximum downlink transmission rate is as follows: For user u1, count the base stations that communicate with user u1 at the same time, and determine whether there are other users in the antenna direction of each base station; When there is only one base station communication antenna with no other users among the base stations communicating with user u1, user u1 directly selects this base station as the optimal base station; If there are no other users in the communication antenna directions of multiple base stations at the same time, the maximum downlink transmission rate is calculated and the base station with the highest speed is selected for data transmission; Maximize the total downlink transmission rate of the system C max The calculation formula is: Where n is the number of base stations in the system; m is the number of users in the system; B ij is the bandwidth of the downlink communication link between the i-th base station and the j-th user, and satisfies B i is the total bandwidth that can be allocated to the i-th base station; P ij is the received power of the downlink communication link between the i-th base station and the j-th user; σ kj The interference power received by the jth user from other kth users; N j is the link noise power received by the jth user; Otherwise, when there are other users on the communication antennas of each base station communicating with user u1, traverse each base station to find the base station B with the maximum downlink transmission rate, and schedule user u1 to communicate with it; Finally, when user u1 arrives at base station B through scheduling and interferes with the original user u3 on base station B, it continues to repeatedly determine whether u3 communicates with other base stations D that meet the maximum downlink transmission rate through scheduling, and repeats the above scheduling so that each user communicates with the base station that reaches its respective maximum downlink transmission rate, ensuring that the interference in each area is small and the frequency occupancy area is average.

2. A communication interference suppression method based on cache forwarding as claimed in claim 1, characterized in that: At least two users that interfere with each other are distributed in the same antenna direction of the at least one base station, specifically as follows: There are two users u1 and u2 that interfere with each other distributed in the same antenna direction of base station A. First, select user u1 for scheduling and determine whether there is a base station B that meets the maximum downlink transmission rate. If so, user u1 communicates with it. Otherwise, user u1 stays at the original base station A and does not move. User u2 is selected for scheduling. If it is determined that there is a base station C that meets the maximum downlink transmission rate, user u2 communicates with it. Otherwise, both users u1 and u2 do not move and continue to communicate with the original base station A. If there are three or more users that interfere with each other distributed in the same antenna direction of the base station, the above judgment process is also applicable.

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