Open-Loop Spatial Multiplexing Reduces Feedback Overhead

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing wireless communication systems face challenges in achieving efficient open-loop spatial multiplexing for radio access virtualization, particularly in reducing feedback overhead and enhancing performance without channel state information (CSI) feedback.

Innovation Solution

The implementation of a system and method for open-loop spatial multiplexing using a processor to spread spreading sequences over multiple antenna ports, employing low-density signature (LDS) structures and message passing algorithms (MPA) for decoding, which allows for simultaneous transmission and reception across multiple antennas without requiring CSI feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If closed loop multi-user MIMO is used to improve performance, then system capacity and user experience are enhanced, but feedback overhead increases significantly

Engineering Contradiction:

Improvesystem performanceVSAvoidfeedback overhead

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The patent segments the MIMO transmission into multiple layers with different spreading sequences, allowing independent processing and reduced coordination overhead between transmit points while maintaining performance benefits

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a centralized processor as an intermediary that coordinates between multiple transmit points and the UE, managing the spreading sequences and reducing the feedback burden on individual transmit points while maintaining system performance

Inventive Principle:

Principle #24Intermediary (Mediator)

2Loss of information

If open loop CoMP is used to reduce feedback overhead, then feedback requirements are minimized, but system gain is limited

Engineering Contradiction:

Improvefeedback overheadVSAvoidsystem gain

Core Design Contradiction:

Loss of informationVSReliability

Solution Approach 1:

The patent changes the parameter of spreading sequence length and density to optimize the balance between feedback overhead and system gain, using variable signature lengths to adapt to different channel conditions and user requirements

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent combines open-loop transmission with structured spreading sequences to create a composite transmission scheme that achieves both reduced feedback overhead and enhanced system gain by integrating multiple transmission techniques

Inventive Principle:

Principle #40Composite materials

3Productivity

If transmit point virtualization is implemented to enhance radio access network capacity, then network capacity and UE experience are improved, but system complexity increases

Engineering Contradiction:

Improvenetwork capacityVSAvoidsystem complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent creates a universal processor that handles multiple transmit points and multiple users simultaneously, providing multi-functional capabilities that reduce overall system complexity while enhancing network capacity through resource virtualization

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentEP2923457B1Systems and methods for open-loop spatial multiplexing schemes for radio access virtualization

Publication Date: 2018.04.04 HUAWEI TECH CO LTD

Figure 1~2
Figure 3~4
Figure 5

AI summary

System and method embodiments are provided for open-loop spatial multiplexing for radio access virtualization. In an embodiment, a system includes a plurality of antenna ports and a processor coupled to the plurality of antenna ports and configured to spread a spreading sequence over at least a portion of the plurality of antenna ports in a spatial domain, wherein the processor is configured to cause the antenna ports to transmit multiple spreading sequences simultaneously by sequence superposition.