KR-20260066617-A - APPARATUS AND METHOD FOR LOW-COMPLEXITY DEMODULATION ALGORITHM OF MULTI-TERMINAL UPLINK TRANSMISSION SIGNAL IN WIRELESS COMMUNICATION SYSTEM

Abstract

The present disclosure generally relates to wireless communication systems, and more specifically to an apparatus and method for a low-complexity demodulation algorithm for a multi-terminal uplink transmission signal in a wireless communication system. A method of operation of a base station according to the present disclosure includes the process of receiving uplink signals from a plurality of single-antenna terminals through a plurality of receiving antennas, the process of selecting rows of a channel matrix using a randomized Kaczmarz algorithm (rKA) in a selection without replacement (SwoR) manner, and the process of selecting rows of the channel matrix includes the process of sequentially processing rows starting from the rows with the highest row selection probability value among the rows belonging to a preset lower transmission rate terminal group.

Inventors

• 곽동혁
• 김대익

Assignees

• 한국전자통신연구원

Dates

Publication Date

20260512

Application Date

20250905

Priority Date

20241104

Claims (1)

1. In a method of operation of a base station for demodulating a multi-terminal uplink signal in a wireless communication system, A process of receiving uplink signals from multiple single-antenna terminals through multiple receiving antennas, and A process of selecting rows of a channel matrix using the randomized Kaczmarz algorithm (rKA) in a selection without replacement (SwoR) manner, and A method for selecting rows of the above-mentioned channel matrix, comprising the process of sequentially processing rows with a high row selection probability value among rows belonging to a preset lower transmission rate terminal group.

Description

Apparatus and Method for Low-Complexity Demodulation Algorithm of Multi-Terminal Uplink Transmission Signal in Wireless Communication System The present disclosure generally relates to a wireless communication system, and more specifically to an apparatus and method for a low-complexity demodulation algorithm of a multi-terminal uplink transmission signal in a wireless communication system. As the number of base station antennas and the maximum number of supported layers increase in wireless communication systems, the importance of multilayer reception is growing. Furthermore, as the number of terminals simultaneously received by a base station increases, the importance of demodulating overlapping multi-terminal uplink transmission signals is also increasing. Conventional multilayer demodulation methods involve inverse matrix operations, so their complexity increases rapidly as the number of support layers increases. The most traditional demodulation methods include Maximum Likelihood (ML) and Minimum Mean Squared Error (MMSE), all of which are algorithms involving inverse matrix operations. The randomized Kaczmarz algorithm (rKA) has been proposed as a suboptimal algorithm to address the problem of increased complexity during multi-terminal uplink transmission signal demodulation. Although rKA is not optimal in terms of demodulation error performance, it does not include inverse matrix operations, so its complexity does not increase significantly despite the growing number of terminals and layers. Furthermore, as it is a variable algorithm capable of adjusting the number of iterations, it has the advantage of improving residual error performance by increasing the number of iterations according to needs and computational capabilities. rKA for uplink reception in multiple terminals can be described as a type of gradient descent performed on each row of the matrix. Several variations of algorithms exist depending on the method of sequentially selecting rows, with the most basic method being sequential based on row index. Additionally, there are variations that utilize sampling with or without replacement based on a probability proportional to the absolute value of each row in the channel matrix. However, existing rKA methods do not consider transmission rate fairness between terminals, leading to a problem where the performance of terminals with lower transmission rates is relatively degraded. Therefore, there is a need for an improved demodulation algorithm that can enhance transmission rate fairness between terminals while maintaining low complexity. FIG. 1 illustrates a flowchart of an improved randomized Katzmaz algorithm according to one embodiment of the present disclosure. FIG. 2 illustrates an operation flowchart of a base station according to one embodiment of the present disclosure. FIG. 3 illustrates an operation flowchart of a terminal according to one embodiment of the present disclosure. FIG. 4 illustrates a configuration diagram of a base station according to one embodiment of the present disclosure. FIG. 5 illustrates a configuration diagram of a terminal according to one embodiment of the present disclosure. The terms used in this disclosure are used merely to describe specific embodiments and are not intended to limit the scope of other embodiments. A singular expression may include a plural expression unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as generally understood by those skilled in the art described in this disclosure. Terms used in this disclosure that are defined in a general dictionary may be interpreted as having the same or similar meaning as they have in the context of the relevant technology, and are not to be interpreted in an ideal or overly formal sense unless explicitly defined in this disclosure. In some cases, even terms defined in this disclosure are not to be interpreted to exclude the embodiments of this disclosure. In the various embodiments of the present disclosure described below, a hardware-based approach is described as an example. However, since the various embodiments of the present disclosure include techniques using both hardware and software, the various embodiments of the present disclosure do not exclude a software-based approach. Additionally, in the detailed description and claims of the present disclosure, “at least one of A, B, and C” may mean “only A,” “only B,” “only C,” or “any combination of A, B, and C.” Additionally, “at least one of A, B, or C” or “at least one of A, B, and/or C” may mean “at least one of A, B, and C.” The present disclosure relates to an apparatus and method for a low-complexity demodulation algorithm for a multi-terminal uplink transmission signal in a wireless communication system. Specifically, the present disclosure describes a technique for improving the performance of a low-transmission rate terminal by improving the randomized Kaczm