NOMA Resource Allocation Using Orthogonal Latin Squares
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Solution Overview
Problem
Non-orthogonal multiple access (NOMA) systems face significant challenges in managing multiple access interferences due to resource allocation methods, which degrade system performance and make it difficult to achieve efficient data transmission, especially in 5G mobile communication systems supporting high data rates and low-latency applications.
Innovation Solution
The proposed solution involves an operation method for base stations and terminals in NOMA-based communication systems, where NOMA resources such as spreading codes and subcarrier mapping patterns are allocated using a mutually-orthogonal Latin square matrix to minimize cross-correlation between resources, thereby reducing multiple access interference. This method ensures that NOMA resources are dynamically allocated to satisfy specific conditions, ensuring orthogonal or different resource usage among terminals, thereby reducing interference variability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If NOMA resources are allocated to multiple terminals simultaneously on the same time, frequency, and space resources, then frequency efficiency and cell capacity are improved, but multiple access interference increases and system performance deteriorates
Solution Approach 1:
The patent applies dynamics by making the NOMA resource allocation time-varying and adaptive. The base station dynamically adjusts the allocation of spreading codes, subcarrier mapping patterns, and other NOMA resources based on channel conditions, terminal locations, and traffic demands. This dynamic allocation allows the system to optimize frequency efficiency while adapting interference management strategies to current system state, resolving the contradiction between high cell capacity and interference control.
Solution Approach 2:
The patent implements local quality by assigning different NOMA resource characteristics to different terminals and resource blocks. Specifically, different spreading codes with varying cross-correlation properties, different subcarrier mapping patterns, and different power allocation ratios are assigned based on local channel conditions, terminal requirements, and interference scenarios. This localized optimization enables simultaneous high capacity and controlled interference in different parts of the system.
2Productivity
If the same NOMA resources are reused across different terminals, then resource utilization efficiency is improved, but interference variability increases and system reliability decreases
Solution Approach 1:
The patent applies periodic action through structured resource sequence patterns. NOMA resources are allocated in periodic sequences where spreading codes, subcarrier mapping patterns, and other resources are systematically reused across terminals and time slots according to predetermined patterns. This periodic structure ensures that resource utilization remains high while interference variability is controlled through the regular, predictable nature of the allocation patterns, thereby maintaining system reliability.
3Speed
If non-orthogonal resource allocation is used to increase data transmission rate, then frequency efficiency is improved, but multiple access interference management becomes more complex
Solution Approach 1:
The patent applies parameter changes by systematically varying key NOMA parameters including spreading code indices, subcarrier mapping patterns, cyclic shifts, and power allocation ratios. These parameter changes are controlled and coordinated across multiple terminals to achieve non-orthogonal resource allocation that increases data transmission rates. The base station manages these parameter variations centrally, transforming the complexity of non-orthogonal allocation into a controllable parameter optimization problem that maintains high throughput while managing interference effectively.
Data Source
AI summary
An operation method of a terminal in a non-orthogonal multiple access (NOMA) based communication system includes receiving information on a NOMA resource sequence allocated by a base station from the base station; and transmitting data to the base station by using a NOMA resource indicated by the information on the NOMA resource sequence in each data symbol or each data symbol group. Also, the NOMA resource sequence may indicate at least one NOMA resource in a NOMA resource set.