A method for reducing interference

Abstract

The invention relates to a method for reducing (minimising) interference between at least one first user equipment (50) connected to the first base station (10) and at least one second user equipment (60) connected to the second base station (30) located in the vicinity of a cell edge (80) area to be implemented by a smart repeater (70) located in the cell edge (80).

Description

[0001] A METHOD FOR REDUCING INTERFERENCE

[0002] TECHNICAL FIELD

[0003] The invention relates to a method for reducing interference by other user equipment or base stations to signals transmitted between a base station and user equipment.

[0004] PRIOR ART

[0005] Base stations and user equipment are the basic components of wireless communication networks. Data communication between these components is one of the key elements of modern communication technology. When a data request or message is sent, a complex communication process begins between the user equipment and the base stations. The user equipment generates a data request transmitted to the surrounding base stations. Base stations process the received signals, direct them when necessary and ensure that they are transmitted back to the user with appropriate frequency and power levels. However, various problems may arise in this process. For example, signal weakening due to buildings or obstacles can reduce communication quality or disconnect the connection completely. Frequency conflicts can prevent or slow down data transmission in dense areas or areas where multiple networks are used together. Additionally, user density is another important factor; when many users are connected simultaneously, network performance may decrease and connection interruptions may occur.

[0006] Today, a flexible and efficient infrastructure is required to meet the rapidly developing needs of wireless communication technologies. Various methods have been developed for this. One of these methods is Time Division Duplexing (TDD). TDD uses the same frequency band for both uplink and downlink transmission, but divides them sequentially over time. For example, while the base station sends data during one time period, user equipment sends data in the next time period. This approach ensures efficient use of spectrum and allows for fast data exchange. Another method is Frequency Division Duplexing (FDD). FDD uses different frequency bands for uplink and downlink data transmission. For example, while the base station sends data in a certain frequency band, user equipment send data in a different frequency band. This approach realises communication using fixed up and down transmission bands.

[0007] Dynamic Time Division Duplexing (D-TDD) is an advanced telecommunications technology particularly useful in wireless communications, which dynamically allocates uplink and downlink channels based on real-time demand. This approach contrasts with traditional fixed allocations in TDD (Time Division Duplexing) or FDD (Frequency Division Duplexing), providing greater flexibility and efficiency in spectrum utilization. D-TDD dynamically adjusts uplink and downlink data transmission according to the needs of the network. For example, in increasing downlink demands, more time slots can be allocated to downlink data transmission to eliminate the imbalance between uplink and downlink data transmission.

[0008] Dynamic Time Division Duplexing (D-TDD) offers several advantages over both TDD and FDD methods. First of all, D-TDD provides flexibility and adaptability. This technology manages communication resources more dynamically by providing flexibility in time domain. This enables rapid adaptation to changing traffic conditions and efficient use of transmission resources. Additionally, D-TDD provides many advantages such as low latency and improved spectrum utilization. This offers a more flexible, efficient and performance-oriented approach in wireless communication systems, providing a significant advantage especially for systems that want to better adapt to changing traffic conditions and demands. This adaptive approach improves network performance, delivering better data speeds and reduced latency.

[0009] However, implementing D-TDD brings some challenges. In particular, cross-link interference (CLI) occurring between adjacent cells can negatively affect the performance in the system. CLI causes signal interference from adjacent base stations. In particular, when a user equipment is located at a cell boundary, these equipment can receive interference signals from another user equipment in adjacent cell called UE-to-UE CLI. Also, a base station can have direct line-of-sight, and when a base station (aggressor) performs downlink transmission, it can create interference to a base station performing uplink reception called gNB-to-gNB CLI. This may cause interference to the communication signals and thus reduce the quality of communication.

[0010] For further development and deployment of this technology, many methods for reducing CLI are proposed in 3GPP standards and academic literature such as scheduling and power control.

[0011] The coverage enhancement for 5G systems is discussed as a critical challenge in 3GPP standards. RF repeaters have been there for years to widen the coverage area, but they work independently and create interference. The usage of RF repeaters allows the coverage area to be expanded by increasing the transmission distance. It is widely used to improve communication quality, especially in remote areas or areas with weak signals. However, there are some risks to using RF repeaters. While these repeaters amplify and retransmit the signals, they may also amplify the noise and create unintended interference. Interference can cause signal degradation or interference and negatively affect communication quality. Therefore, RF repeaters need to be carefully positioned and managed. If they are not properly planned or located, the risk of interference may increase and adversely affect the performance of the communication system.

[0012] Application WO2023131455A1 discloses the system and method for transmitting data by a communication device and an infrastructure equipment in a wireless communication network. The system includes a repeater, a first radio node and a terminal. The first radio node provides a wireless access interface to communicate with the terminal. The repeater provides monitoring from the first radio node of a first indication that the first radio node supports a network-controlled repeater. When the first indicator is detected, first control information is received from the first radio node and the repeater is operated in network controlled repeater mode for the first radio node and based on the first control information, and when the first indicator is not detected, the repeater is operated in autonomous repeater mode. Thus, data transmission is ensured efficiently. However, the mentioned system is insufficient to fully prevent interference.

[0013] All the problems mentioned above have made it necessary to make an innovation in the relevant technical field as a result.

[0014] BRIEF DESCRIPTION OF THE INVENTION

[0015] The present invention relates to a method to eliminate the above-mentioned disadvantages and bring new advantages to the relevant technical field.

[0016] An object of the invention is to provide a method for reducing interference caused by other base stations and user equipment during data exchange between the base station and the user equipment.

[0017] A further object of the invention is to provide a method for increasing the signal strength.

[0018] To achieve all the objects mentioned above and that will emerge from the following detailed description, a method for reducing interference between at least one first user equipment connected to the first base station and at least one second user equipment connected to the second base station located in the vicinity of a cell edge area to be implemented by a smart repeater located in the cell edge. Accordingly, it comprises the following steps in case it comprises the steps of receiving a first time division duplex configuration from the first base station, receiving a second time division duplex configuration from the second base station, comparing the first time division duplex configuration with the second time division duplex configuration and detecting slots where cross-link interference is likely to occur, detecting cross-link interferences by measuring interference levels at the slots where cross-link interference is likely to occur based on the comparison of the first time division duplex configuration and the second time division duplex configuration, receiving the first signal generated from the first user equipment to be transmitted to the first base station in the uplink direction from the first user equipment in case it is determined that the interference from the first user equipment to the second user equipment is greater than the reference interference, directing the first received signal to be transmitted to the first base station, receiving the second signal generated from the second base station to be transmitted to the second user equipment in the downlink direction from the second base station in case it is determined that the interference from the first user equipment to the second user equipment is less than the reference interference, directing the second received signal to be transmitted to the second user equipment.

[0019] A possible embodiment of the invention is characterized comprising the steps of; the method further comprises steps of receiving the signal transmitted from the first user equipment to the first base station in case it is detected that at least two user equipment connected to the second base station operating in the downlink direction are exposed to interference from the first user equipment, directing the received signal from the first user to be transmitted to the first base station.

[0020] BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a drawing illustrating schematic view of the data transmission direction between the first base station and the first user equipment.

[0022] Figure 2 is a drawing illustrating schematic view of the data transmission direction between the second base station and the second user equipment.

[0023] REFERENCE NUMBERS GIVEN IN THE FIGURE

[0024] 10 First base station

[0025] 20 First cell

[0026] 30 Second base station

[0027] 40 Second cell

[0028] 50 First user equipment

[0029] 60 Second user equipment

[0030] 70 Smart repeater

[0031] 80 Cell edge DETAILED DESCRIPTION OF THE INVENTION

[0032] In this detailed description, the subject matter is explained with references to examples without forming any restrictive effect only in order to make the subject more understandable.

[0033] The invention relates to a method to be realized by a smart repeater provided between a base station and a user equipment. The mentioned method provides for the reduction of interference to the signals transmitted between the base station and the user equipment by other user equipment or base stations. In the method disclosed herein, the interference that occurs when at least two base stations and at least one user equipment connected to each base station communicates with the base stations is reduced. However, the invention is not limited to this description. The method has been developed in such a way that the interference caused by the base stations and the user equipment within the coverage area of the said base stations during the communication is reduced by smart repeater (70). In a possible embodiment of the invention, it is preferred to use network-controller repeater (NCR) as a smart repeater (70).

[0034] As is well known in the art, smart repeater (70) provides the data exchange between wireless networks' base stations and user equipment to be strengthened. The smart repeater (70) receives the signals coming from the base station, strengthens them and retransmits them over the intended region / direction of transmission. Thus, the coverage area increases significantly. Smart repeater (70) includes a control unit, a receiver unit, a transmitter unit and power supply. Additional functions in smart repeaters make it superior and smarter than traditional repeaters, including time division duplex (TDD) information access, on / off status, and multi-beam operation. To incorporate these features, a control unit is added to NCR that performs simple baseband processing to retrieve the side information from the control signals sent by the base station. The control unit helps to improve its performance, it can exploit TDD information for efficient amplification and forward relaying or beamform the signals toward the users and base station by utilising the received side control information. Besides, with on / off information, it can turn off to save power and avoid the unnecessary amplification of noise signals. Control unit allows increasing the frequency and power range of the signal, expanding the network coverage area and improving the signal quality. The power supply meets the energy needs of smart repeaters (70). The forwarding unit of the smart repeater consists of receiver, amplifier and transmitter units. The task of the forwarding unit is amplifying and forwarding the incoming signal in accordance with the sidelink information provided by the control unit without performing baseband processing on the forwarded signal.

[0035] An exemplary operating scenario of the invention is described as follows.

[0036] In a first coverage area (20) (first cell), there is a first base station (10) operating in the uplink direction. There is a first user equipment (50) that provides data exchange with the first base station (10). In a second coverage area (40) (second cell), there is a second base station (30) operating in the downlink direction. There is a second user equipment (60) that provides data exchange with the second base station (30).

[0037] There could be cell edge areas where the cell coverage regions of two base stations can intersect due to the deployment scenario of the network. If first user equipment (50) and second user equipment (60) are close to the cell edge (80), interference may occur between first user equipment (50) and second user equipment (60) and between first base station (10) and second base station (30). Smart repeater (70) is placed in this cell edge (80) area. Thus, communication can be easily established with each base station and each user equipment. Especially the signal which is weakened due to the presence of buildings etc. between the base station and the user equipment that block the coverage area is strengthened.

[0038] As shown in Figure 1 , smart repeater (70) placed in the cell edge (80) area firstly ensures that a first time division duplex configuration is received from first base station (10). Smart repeater (70) provides the reception of a second time division duplex configuration from second base station (30). These operations are performed by means of a control unit provided in smart repeater (70). The control unit ensures data exchange between base station and user equipment through receiver unit and transmitter unit. Control unit enables the detection of cross-link interference by comparing the first time division duplex configuration with the second time division duplex configuration. Because cross-link interference occurs at points where two base stations operate in different directions of transmission. Thus, control unit can determine in advance that interference will occur at these times depending on the transmission direction. Control unit ensures that the first signal is received to be transmitted from first user equipment (50) to first base station (10) in uplink direction, if it is determined / informed that the interference made by first user equipment (50) to second user equipment (60) is greater than the reference interference. Thus, while the received power of the signal coming from the first user equipment (30) to the first base station (60) is increased, the output power of the first user equipment is reduced. This reduces the interference generated by the first user equipment to the second user equipment (30). Furthermore, it increases the received power of the first base station making the transmission more robust against gNB-to-gNB CLI. Forwarding unit directs the received signal to be transmitted to first base station (10) via transmitter unit.

[0039] As shown in Figure 2; if control unit detects / gets informed that the interference from the first user equipment to the second user equipment is less than the reference interference, it ensures that the second signal is received from the second base station (30) to be transmitted to the second user equipment (60) in the downlink direction. The control unit ensures that the second signal received through the receiver unit is directed to be transmitted to the second user equipment (60). Thus, while signal strength of the second user equipment from the second base station (30) is increased, the output power of the second base station (30) is reduced. Additionally, the interference from the second base station (30) to the first base station (10) is reduced.

[0040] In an alternative embodiment of the invention, if more than one user equipment is connected to a base station operating in the downlink direction, where there is another user equipment connected to a second base station operating in the uplink, and the UL user equipment interferes with the downlink users, the smart repeater control unit decides to connect to the base station operating in the uplink direction and provide signal transmission in the uplink direction. Here, the data received from the user equipment located closest to the base station operating in the uplink direction is transmitted to the base station. Thus, interference from the user equipment connected to the base station that operates in UL to user equipment connected to the base station that operates in DL is reduced.

[0041] In order to achieve all the objects stated above and arising from the above detailed description, the present invention relates to a method for reducing (minimising) interference between at least one first user equipment (50) connected to the first base station (10) and at least one second user equipment (60) connected to the second base station (30) located in the vicinity of a cell edge area (80) to be implemented by a smart repeater (70) located in the cell edge (80). This method is characterized by including the following steps;

[0042] - receiving a first time division duplex configuration from the first base station (10),

[0043] - receiving a second time division duplex configuration from the second base station (30),

[0044] - comparing the first time division duplex configuration with the second time division duplex configuration and detecting slots where cross-link interference is likely to occur,

[0045] - detecting cross-link interferences by measuring interference levels at the slots where cross-link interference is likely to occur based on the comparison of the first time division duplex configuration and the second time division duplex configuration,

[0046] - receiving the first signal generated from the first user equipment (50) to be transmitted to the first base station (10) in the uplink direction from the first user equipment (50) in case it is determined that the interference from the first user equipment (50) to the second user equipment (60) is greater than the reference interference,

[0047] - directing the first received signal to be transmitted to the first base station (10),

[0048] - receiving the second signal generated from the second base station (30) to be transmitted to the second user equipment (60) in the downlink direction from the second base station (30) in case it is determined that the interference from the first user equipment to the second user equipment is less than the reference interference,

[0049] - directing the second received signal to be transmitted to the second user equipment (60).

[0050] A possible embodiment of the invention is that this method includes the step of receiving the signal transmitted from the first user equipment (50) to the first base station (10) in case it is detected that at least two user equipment connected to the second base station (10) operating in the downlink direction are exposed to interference from the first user equipment (50), directing the received signal to be transmitted to the first base station (10).

[0051] The scope of protection of the invention is specified in the attached claims and cannot be limited to those explained for sampling purposes in this detailed description. It is evident that a person skilled in the art may exhibit similar embodiments in light of the above-mentioned facts without drifting apart from the main theme of the invention.

Claims

CLAIMS1. A method for reducing (minimising) interference between at least one first user equipment (50) connected to the first base station (10) and at least one second user equipment (60) connected to the second base station (30) located in the vicinity of a cell edge area to be implemented by a smart repeater (70) located in the cell edge (80) characterised in that; it comprises the steps of- receiving a first time division duplex configuration from the first base station (10),- receiving a second time division duplex configuration from the second base station (30),- comparing the first time division duplex configuration with the second time division duplex configuration and detecting slots where cross-link interference is likely to occur,- detecting cross-link interferences by measuring interference levels at the slots where cross-link interference is likely to occur based on the comparison of the first time division duplex configuration and the second time division duplex configuration,- receiving the first signal generated from the first user equipment (50) to be transmitted to the first base station (10) in the uplink direction from the first user equipment (50) in case it is determined that the interference from the first user equipment (50) to the second user equipment (60) is greater than the reference interference,- directing the first received signal to be transmitted to the first base station (10),- receiving the second signal generated from the second base station (30) to be transmitted to the second user equipment (60) in the downlink direction from the second base station (30) in case it is determined that the interference from the first user equipment to the second user equipment is less than the reference interference,- directing the second received signal to be transmitted to the second user equipment (60).

2. The method according to claim 1 , is characterized in that the method further comprises steps of receiving the signal transmitted from the first user equipment (50) to the first base station (10) in case it is detected that at least two user equipment connected to the second base station (30) operating in the downlink direction are exposed to interference from the first user equipment (50), directing the received signal to be transmitted to the first base station (10).

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