SCMA Encoding Matrix Diversity Order Configuration

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Solution Overview

Problem

The existing multiple-access techniques in mobile communication systems, such as SCMA, face challenges in improving multiuser detection performance due to identical diversity orders for encoding modes, limiting network capacity and resource utilization.

Innovation Solution

A method and device for configuring a code superposition-based multiuser encoding mode, where a network device determines and configures different columns in a preconfigured encoding matrix for User Equipments (UEs) to enable each UE to transmit data with varying diversity orders, based on received power and interference levels, thereby enhancing multiuser detection performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If SCMA technique uses identical diversity orders for encoding modes of multiple users, then the encoding structure is simplified, but the multiuser detection performance deteriorates

Engineering Contradiction:
Improveencoding structure complexityVSAvoidmultiuser detection performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies local quality by assigning different diversity orders to different users' encoding modes within the same SCMA system. Specifically, the network device configures different columns from a preconfigured encoding matrix for different users, where each column corresponds to a different diversity order. This allows the system to maintain simplified overall structure while providing differentiated diversity orders locally for each user, thereby improving multiuser detection performance without significantly increasing system complexity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the diversity order parameter of encoding modes for different users. The network device determines received power levels of different users and configures encoding modes with diversity orders adapted to each user's channel conditions. Users with better channel conditions receive encoding modes with lower diversity orders, while users with poorer conditions receive higher diversity orders, optimizing overall system performance.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If orthogonal mode is used for multiple users, then interference between users is reduced, but network capacity and resource utilization deteriorate

Engineering Contradiction:
Improveinterference between usersVSAvoidnetwork capacity
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent introduces asymmetry by using non-orthogonal encoding modes for different users in SCMA. Instead of assigning orthogonal resources to each user, the system assigns different sparse code patterns with different diversity orders, creating an asymmetric encoding structure that allows multiple users to share the same time-frequency resources without complete orthogonality, thereby increasing network capacity while managing interference through the sparse code structure.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent implements dynamic resource allocation by having the network device dynamically determine and configure encoding modes for different users based on their received power levels and channel conditions. The network device can adaptively assign different columns from the encoding matrix to different users, allowing the system to dynamically optimize resource utilization and network capacity while maintaining acceptable interference levels through the sparse code structure.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3236634B1Method and device for configuring and determining a code superposition-based multiuser encoding mode
Publication Date: 2020.01.08 CHINA ACAD OF TELECOMM TECH
  • EP3236634B1 patent drawingFigure 1~2
  • EP3236634B1 patent drawingFigure 3~5
  • EP3236634B1 patent drawingFigure 6~7

AI summary

A method and a device for configuring and determining a code superposition-based multiuser encoding mode are provided. The configuring method includes steps of: determining, by a network device, UEs by which an identical transmission resource is to be multiplexed; and configuring, by the network device, different columns in a preconfigured encoding matrix formed through multiuser code superposition for the UEs, so as to enable each UE to transmit data in accordance with an encoding mode corresponding to the column configured by the network device, at least two columns in the encoding matrix having different diversity orders.