Uplink Pre-Coding Determination via Downlink Resources

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Solution Overview

Problem

In New Radio communication systems, the existing methods for uplink transmission require significant control signaling overhead due to the slow changes in analog beams and wideband pre-coding matrices, which are typically indicated in Downlink Control Information (DCI), leading to inefficiencies in resource allocation and signaling.

Innovation Solution

A method where a terminal device determines a target downlink resource and corresponding uplink pre-coding information, allowing it to transmit an uplink signal using a predetermined relationship between downlink and uplink resources, thereby reducing the need for explicit pre-coding information in control signaling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If uplink pre-coding information is transmitted in DCI of scheduling data, then the terminal device can obtain accurate pre-coding information for uplink transmission, but a large control signaling overhead is required

Engineering Contradiction:

Improveaccuracy of uplink pre-coding informationVSAvoidcontrol signaling overhead

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent extracts the wideband pre-coding matrix indication from the DCI control signaling and removes it, keeping only the narrowband pre-coding matrix in DCI. The wideband pre-coding matrix is obtained by the terminal device through autonomous determination based on downlink channel information, thereby eliminating the signaling overhead while maintaining transmission accuracy.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The terminal device is empowered to autonomously determine the wideband pre-coding matrix through self-service mechanisms. By utilizing downlink channel information and a predetermined correspondence relationship, the terminal device independently derives the wideband pre-coding matrix without requiring network side indication, thus reducing control signaling overhead while ensuring accurate uplink pre-coding.

Inventive Principle:

Principle #25Self-service

2Adaptability or versatility

If analog beam and wideband pre-coding matrix are indicated in DCI, then the terminal device can adapt to channel changes, but the control signaling overhead increases significantly

Engineering Contradiction:

Improveadaptability to channel changesVSAvoidcontrol signaling overhead

Core Design Contradiction:

Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent segments the pre-coding information into two distinct parts: wideband pre-coding matrix and narrowband pre-coding matrix. The wideband component changes slowly and is determined autonomously by the terminal device, while the narrowband component changes rapidly and is indicated in DCI. This segmentation allows the system to maintain adaptability to channel changes while significantly reducing control signaling overhead.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The terminal device performs preliminary determination of the wideband pre-coding matrix in advance, before the actual uplink transmission. By using downlink channel information and a predetermined correspondence relationship, the terminal device pre-computes the wideband pre-coding matrix, eliminating the need for real-time indication in DCI and reducing signaling overhead while maintaining adaptability.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If beam training is performed to determine uplink transmission beam, then the terminal device can achieve optimal beamforming gain, but the time and signaling resources are consumed

Engineering Contradiction:

Improvebeamforming gainVSAvoidtime for beam training

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent inverts the traditional beam training approach by using downlink channel information to determine uplink pre-coding matrices. Instead of the terminal device transmitting multiple beams for the network to select, the network provides downlink channel information that enables the terminal to autonomously determine the appropriate uplink pre-coding matrix through a predetermined correspondence relationship, thereby reducing beam training time while maintaining beamforming gain.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The downlink channel information serves as an intermediary that bridges the gap between downlink and uplink channel characteristics. By using this intermediary information, the terminal device can infer the appropriate uplink pre-coding matrix without performing extensive beam training, thus reducing time consumption while achieving optimal beamforming performance.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS10873378B2Method and device for transmitting uplink signals

Publication Date: 2020.12.22 GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP LTD

AI summary

A method and device for transmitting an uplink signal are provided. The method includes: determining, by a terminal device, a target downlink resource for transmitting a target downlink signal among a plurality of downlink resources; determining, by the terminal device, target uplink pre-coding information according to the target downlink resource and a predetermined corresponding relationship, wherein the predetermined corresponding relationship is a corresponding relationship between downlink resources and uplink pre-coding information; and transmitting, by the terminal device, an uplink signal according to the target uplink pre-coding information.