KR-20260062424-A - BASE STATION, AND METHOD FOR DETERMINIGG DOWNLINK RETRANSMISSION POWER

Abstract

The present invention relates to a method for controlling downlink retransmission power according to downlink transmission failure factors in a Massive MIMO (Multiple-Input and Multiple-Output) operating environment.

Inventors

• 김용옥

Assignees

• 에스케이텔레콤 주식회사

Dates

Publication Date

20260507

Application Date

20241029

Claims (11)

1. Memory containing instructions; and A base station characterized by including a processor that, by executing the above command, determines whether the transmission failure is due to insufficient transmission power based on the channel state information of the terminal when a transmission failure is confirmed from the HARQ-ACK information of the terminal for downlink transmission, and if the transmission failure is due to insufficient transmission power, determines the transmission power for downlink retransmission to be higher than the previous downlink transmission time.
2. In Article 1, The above channel status information is, It includes a received SINR (Signal to Interference plus Noise Ratio) of a PUCCH (Physical Uplink Control Channel) in which HARQ-ACK information is received from the above terminal, The above processor is, A base station characterized by determining the transmission failure factor as insufficient transmission power when the reception SINR of the above PUCCH is below a predefined threshold.
3. In Article 1, The above channel status information is, It includes a received SINR (Signal to Interference plus Noise Ratio) of the PDSCH (Physical Downlink Shared Channel) in which downlink transmission is performed for the above terminal, The above processor is, A base station characterized by determining the transmission failure factor as insufficient transmission power when the reception SINR of the PDSCH calculated at the terminal is found to be below a predefined threshold.
4. In Paragraph 3, The above processor is, A resource set for receiving HARQ-ACK information from the above terminal is set as a first resource set and a second resource set different from the first resource set, and A base station characterized by receiving a failure response (NACK) of HARQ-ACK information from the terminal through a dedicated resource set designated as the first resource set or the second resource set when the received SINR of the above PDSCH is less than a predefined threshold.
5. In Article 1, The above processor is, A base station characterized by selecting a Redundancy Value (RV) containing more source bits (Systematic bits) for downlink retransmission when transmission failure factors are determined to be insufficient transmission power.
6. In a method for determining downlink retransmission power performed at a base station, A determination step for determining whether the cause of transmission failure is insufficient transmission power based on the channel state information of the terminal when a transmission failure is confirmed from the HARQ-ACK information of the terminal regarding downlink transmission; and A method for determining downlink retransmission power, characterized by including a determination step of determining the transmission power for downlink retransmission to be higher than the previous downlink transmission point when a transmission power shortage is determined due to the transmission failure factor mentioned above.
7. In Article 6, The above determination step is, A method for determining downlink retransmission power, characterized by confirming the received SINR (Signal to Interference plus Noise Ratio) of a PUCCH (Physical Uplink Control Channel) receiving HARQ-ACK information from the terminal as channel status information, and determining the transmission failure factor as insufficient transmission power when the received SINR of the PUCCH is below a predefined threshold.
8. In Article 1, The above determination step is, A method for determining downlink retransmission power, characterized by checking the received SINR (Signal to Interference plus Noise Ratio) of a Physical Downlink Shared Channel (PDSCH) for which downlink transmission is performed for the terminal using the channel status information, and determining the transmission failure factor as insufficient transmission power when the received SINR of the PDSCH calculated at the terminal is less than a predefined threshold.
9. In Article 8, The above method is, The method further includes a setting step of setting a resource set for receiving HARQ-ACK information from the terminal as a first resource set and a second resource set different from the first resource set. The above terminal is, A downlink retransmission power determination method characterized by transmitting a failure response (NACK) of HARQ-ACK information to the base station through a dedicated resource set designated as the first resource set or the second resource set when the received SINR of the above PDSCH is less than a predefined threshold.
10. In Article 6, The above method is, A method for determining downlink retransmission power, characterized by further including a selection step for selecting a Redundancy Value (RV) containing more source bits (Systematic bits) for downlink retransmission, when transmission power shortage is determined as the transmission failure factor, compared to when the transmission failure factor is not transmission power shortage.
11. A computer program stored on a medium to execute the method of any one of claims 6 to 10, combined with hardware.

Description

Base Station and Method for Determining Downlink Retransmission Power The present invention relates to a method for controlling downlink retransmission power according to downlink transmission failure factors in a Massive MIMO (Multiple-Input and Multiple-Output) operating environment. In 5G NR systems, Massive MIMO (Multiple-Input and Multiple-Output) technology begins to be applied in earnest, and Radio Units (RUs) with more than 32 antennas are installed. As these RU devices support high-power transmission, interference caused by coverage overlap in RU devices, including Massive MIMO antennas, and excessive power consumption due to high-power devices are new issues in mobile communication networks that did not exist before in 5G NR systems. Regarding this, while transmission power regulation is a good means to resolve these issues, base stations may face transmission power shortage issues because it is difficult to accurately determine the SINR (Signal to Interference plus Noise Ratio) required by terminals. In particular, if insufficient transmission power is the cause of a downlink transmission failure, a situation may arise where downlink retransmissions also fail consecutively, leading to serious service-related issues such as call disconnection or data stall. FIG. 1 is an exemplary diagram for explaining a mobile communication system environment according to an embodiment of the present invention. FIG. 2 is a configuration diagram for explaining a base station according to an embodiment of the present invention. FIGS. 3 and 4 are flowcharts for explaining a method for determining downlink retransmission power according to an embodiment of the present invention. Hereinafter, various embodiments of the present invention will be described with reference to the attached drawings. The present invention relates to a technique for controlling downlink retransmission power in a Massive MIMO (Multiple-Input and Multiple-Output) operating environment. In 5G NR systems, Massive MIMO technology has begun to be applied in earnest, and Radio Units (RUs) with more than 32 antennas are being installed and operated in commercial networks. These RUs supporting Massive MIMO are high-power devices, and when operated at maximum power, coverage between cells overlaps, which can cause interference with adjacent cells. Additionally, high power consumption due to high power usage can also be a problem. Therefore, during downlink transmission, it is necessary to adjust transmission power based on the terminal's channel status, cell congestion, and traffic requirements per terminal. Generally, for strong-field terminals with good channel conditions, transmission power may be allocated at a lower level, while for weak-field terminals with poor channel conditions, transmission power may be allocated at a higher level to ensure reception performance. In addition, if transmission power is artificially lowered during allocation, more time and frequency resources are consumed to secure an equivalent data rate. Therefore, if the cell is congested and time/frequency resources are insufficient, transmission power is allocated to the maximum to conserve time/frequency resources, whereas otherwise, transmission power is reduced to maximize the use of time/frequency resources. For terminals with high traffic demands, high-speed transmission is required to minimize transmission time, so the maximum transmission power can be allocated. As described above, transmission power for downlink transmission of the base station can be adjusted according to the situation, thereby enabling efficient reduction of the impact of adjacent cell interference and downlink transmission power consumption. As such, while transmission power regulation is a good means to resolve various issues arising in mobile communication systems, such as interference and excessive power consumption, base stations find it difficult to accurately determine the Signal to Interference plus Noise Ratio (SINR) required by terminals, which can lead to transmission power shortage issues. In particular, if insufficient transmission power is the cause of a downlink transmission failure, a situation may arise where downlink retransmissions also fail consecutively, leading to serious service-related issues such as call disconnection or data stall. Accordingly, in one embodiment of the present invention, a novel method is proposed to control the entire downlink transmission area according to the transmission failure factor in the event of a downlink transmission failure. In this regard, FIG. 1 illustrates an exemplary mobile communication system environment according to one embodiment of the present invention. As illustrated in FIG. 1, in a mobile communication system environment (e.g., 5G NR) according to one embodiment of the present invention, a base station (100) may be included that maintains or increases transmission power depending on the transmission failure factor during downlin