Rate Splitting for MU-MIMO Interference Management

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current wireless communication technologies, such as LTE and NR, face challenges in efficiently managing interference between multiple user equipment (UEs) in multi-user multiple-input multiple-output (MU-MIMO) systems, particularly when UEs are not spatially aligned, leading to suboptimal performance and throughput.

Innovation Solution

The implementation of rate splitting techniques using first and second layers, where data is allocated into distinct parts and multiplexed, with the first part being transmitted without interference rejection for multicasting and the second part using interference rejection for unicasting, allowing UEs to decode their specific data even when they are not spatially aligned.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If interference rejection techniques are used for all data parts in MU-MIMO systems, then spatially aligned UEs can achieve good performance, but UEs that are not spatially aligned cannot decode their data effectively

Engineering Contradiction:

Improvedata decoding reliabilityVSAvoidadaptability to different UE spatial alignments

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The data is divided into two distinct parts: a first part that is common to multiple UEs and does not require interference rejection, and a second part that is specific to individual UEs and uses interference rejection techniques. This segmentation allows the system to handle both spatially aligned and non-spatially aligned UEs effectively, as each part can be processed according to its specific requirements.

Inventive Principle:

Principle #1Segmentation

2Reliability

If rate splitting is implemented with separate first and second layers, then UEs can decode their specific data effectively, but the system complexity increases

Engineering Contradiction:

ImproveUE data decoding effectivenessVSAvoidsystem complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The transmission is divided into two layers: a first layer carrying a first part of data that can be decoded by multiple UEs, and a second layer carrying a second part of data with UE-specific information. This segmentation enables effective data decoding while managing system complexity through structured organization of data parts and layers.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different quality levels are applied to different parts of the data transmission. The first part uses a more robust transmission mode suitable for multiple UEs, while the second part uses enhanced interference rejection techniques for specific UEs. This local differentiation optimizes performance while controlling overall system complexity.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS11611416B2Rate splitting using first layers and second layers

Publication Date: 2023.03.21 QUALCOMM INC

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a transmitter device may allocate data associated with a user equipment (UE), of two or more UEs, into at least one of a first part, a second part, or a combination thereof; multiplex the first part of the data associated with the UE with a first part of data associated with one or more other UEs, of the two or more UEs, to form multiplexed data; map the multiplexed data to a first set of layers; and map the second part of the data associated with the UE and a second part of the data associated with the one or more other UEs to a second set of layers. Numerous other aspects are provided.