KR-20260064068-A - TERMINAL, AND UPLINK SCHEDULING METHOD

Abstract

The present invention relates to a method for applying a Modulation and Coding Scheme (MCS) table that is more suitable for a wireless channel environment in units of Transmission Time Intervals (TTI) of the uplink.

Inventors

• 이경빈

Assignees

• 에스케이텔레콤 주식회사

Dates

Publication Date

20260507

Application Date

20241031

Claims (7)

1. In the terminal, Memory containing instructions; and A terminal characterized by including a processor that, by executing the above command, transmits a Power Headroom Report (PHR) to a base station and determines a Modulation and Coding Scheme (MCS) for uplink transmission using a 64QAM table or a 256QAM table based on Downlink Control Information (DCI) received from the base station for the transmission of the PHR.
2. In Article 1, The above DCI is, It includes DCI format 0, which is a scheduling information type for PUSCH (Physical Uplink Shared Channel), and The above processor is, A terminal characterized by using a 64QAM table or a 256QAM table depending on the bit value of a specific field defined in the above DCI format 0.
3. In Article 1, The above base station is, Based on a reference value set at the base station for the above PHR, if the value of the above PHR is less than or equal to the reference value, it is decided to use a 64QAM table at the terminal, and A terminal characterized by deciding to use a 256QAM table in the case where the value of the above PHR exceeds a reference value.
4. In an uplink scheduling method performed at a terminal, Transmission step of transmitting PHR (Power Headroom Report) to a base station; A receiving step of receiving DCI (Downlink Control Information) from the base station regarding the transmission of the above PHR; and An uplink scheduling method characterized by including a decision step of determining a Modulation and Coding Scheme (MCS) for uplink transmission using a 64QAM table or a 256QAM table based on the above DCI.
5. In Article 4, The above DCI is, It includes DCI format 0, which is a scheduling information type for PUSCH (Physical Uplink Shared Channel), and The above decision step is, An uplink scheduling method characterized by using a 64QAM table or a 256QAM table depending on the bit value of a specific field defined in the above DCI format 0.
6. In Article 1, The above base station is, Based on a reference value set at the base station for the above PHR, if the value of the above PHR is less than or equal to the reference value, it is decided to use a 64QAM table at the terminal, and An uplink scheduling method characterized by deciding to use a 256QAM table at the terminal when the value of the above PHR exceeds a reference value.
7. A computer program stored on a medium to execute the method of any one of claims 4 to 6, combined with hardware.

Description

Terminal, and Uplink Scheduling Method The present invention relates to a method for applying a Modulation and Coding Scheme (MCS) table that is more suitable for a wireless channel environment in units of Transmission Time Intervals (TTI) of the uplink. In mobile communication systems, an MCS (Modulation and Coding Scheme) table is used to set the uplink transmission speed according to the wireless channel environment. There are MCS-tables that support up to 64QAM and tables that support up to 256QAM. When using a 64QAM table, the maximum transmission speed is lower compared to a 256QAM table, and when using a 256QAM table, the channel environment is not subdivided compared to a 64QAM table, so the transmission speed cannot be set efficiently in cases of poor channel environment. Therefore, in order to optimize transmission speeds based on the wireless channel environment in each region where base stations are installed, a method is needed to select and use an MCS-table according to the situation. However, previously, the MCS-table to be referenced for the currently implemented uplink channel was transmitted via the MCS-table information within the RRC message, and the terminal had to use the MCS-table information configured to be referenced continuously as long as it was in the RRC connected state. Therefore, if the wireless channel environment changes, transmission performance over the uplink channel may deteriorate due to the use of an unsuitable MCS-table. 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 terminal according to an embodiment of the present invention. FIG. 3 is a flowchart for explaining an uplink scheduling method 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 technology for optimizing and operating transmission speeds according to the wireless channel environment for each region where base stations are installed. The process of converting information into electrical signals for storage and transmission, and changing the amplitude, frequency, and phase information of a carrier signal according to the desired information, is called modulation. In other words, modulation is the process of converting signal strength, displacement, frequency, or phase into an appropriate waveform form to match the channel characteristics of the transmission medium. In particular, digital modulation refers to the process of converting a digital signal to be transmitted into a signal suitable for channel characteristics by matching digital information to one of several possible signals. Representative digital modulation schemes include QPSK, 16QAM, 64QAM, and 256QAM. Using this modulation method, the terminal transmits data to the base station, and the base station can receive and demodulate the transmitted data. However, due to the recent explosive increase in the number of terminals and data usage, the volume of data transmission and reception between terminals and base stations is increasing, and there is a growing demand for modulation schemes capable of processing large amounts of data traffic at high speeds. The base station selects one of various modulation methods considering the uplink channel conditions and notifies the terminal via an RRC message, and the terminal confirms and uses the received uplink information to transmit data. In other words, mobile communication systems use a table that supports up to 64QAM and an MCS (Modulation and Coding Scheme)-table that supports up to 256QAM to set the transmission speed according to the wireless channel environment. When using a 64QAM table, the maximum transmission speed is lower compared to a 256QAM table, and when using a 256QAM table, the channel environment is not subdivided compared to a 64QAM table, so the transmission speed cannot be efficiently set in cases of poor channel environment. Therefore, in order to optimize transmission speeds based on the wireless channel environment in each region where base stations are installed, a method is needed to select and use an MCS-table according to the situation. However, in the past, which modulation coding configuration table to refer to for the currently implemented uplink channel was transmitted through the MCS-table information within the RRC message, and the terminal had to use the MCS-table information that was set to be referenced once continuously when in the RRC connected state. Therefore, if the wireless channel environment changes, transmission performance over the uplink channel may significantly degrade due to the use of an unsuitable MCS-table. Accordingly, in one embodiment of the present invention, a method is proposed to apply an MCS-table suitable for a wireless channel environment in units