Uplink Beam Spatial Information via Downlink Reciprocity

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Solution Overview

Problem

Current communication systems face challenges in determining the uplink transmit beam's spatial information efficiently, particularly in 5G networks, where beam alignment between user equipment (UE) and base stations is critical for effective signal transmission.

Innovation Solution

The method involves using the spatial reciprocity of beams to infer the transmit angle of the uplink transmit beam based on the angle of arrival of the downlink receive beam, allowing the UE to determine the uplink transmit beam by referencing the downlink receive beam's spatial information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional beam sweeping and measurement methods are used to determine uplink transmit beam spatial information, then beam alignment accuracy can be achieved, but the process complexity and time consumption increase significantly

Engineering Contradiction:
Improvebeam alignment accuracyVSAvoidtime consumption for beam determination
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by having the network device pre-send downlink reference signals with known spatial information before the UE needs to determine uplink transmit beam direction. This allows the UE to obtain spatial parameters in advance through downlink channel measurement, eliminating the need for time-consuming uplink beam sweeping and measurement processes.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses downlink channel measurement results as an intermediary to transfer spatial information from the network device to the UE. Instead of direct uplink beam training, the UE measures the downlink channel characteristics and uses these measurements to infer the optimal uplink transmit beam direction, making the spatial information transfer more efficient.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If extensive beam sweeping and measurement are performed to ensure accurate spatial information, then communication reliability improves, but the process complexity increases

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidprocess complexity for beam determination
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The network device performs preliminary spatial configuration by sending downlink reference signals with embedded spatial information before uplink transmission. This preliminary action ensures that the UE has accurate spatial parameters available, maintaining communication reliability while avoiding complex beam sweeping procedures.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses the concept of copying by having the UE copy spatial information from downlink channel measurements to uplink transmit beam configuration. The spatial characteristics observed in the downlink channel are copied and applied to determine the uplink beam direction, simplifying the overall process while maintaining accuracy through the reciprocity of wireless channels.

Inventive Principle:
Principle #26Copying

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach simplifies the process of determining uplink transmit beams, reducing the need for extensive sweeping and measurement, and enhances communication efficiency by aligning beams effectively in 5G networks.

Implementation Method 1

The method involves using the spatial reciprocity of beams to infer the transmit angle of the uplink transmit beam based on the angle of arrival of the downlink receive beam

Methodology Applied
Scientific EffectSpatial reciprocity:

Data Source

PatentEP3944509B1Signal transmission method and apparatus
Publication Date: 2023.10.25 HUAWEI TECH CO LTD
  • EP3944509B1 patent drawingFigure 1~2
  • EP3944509B1 patent drawingFigure 3a~3b
  • EP3944509B1 patent drawingFigure 4~5a

AI summary

Embodiments of the present invention provide a signal transmission method. User equipment receives a first signal from a wireless network device; and the user equipment determines spatial information of a to-be-transmitted second signal based on the first signal, and transmits the to-be-transmitted second signal by using the spatial information. An uplink transmit beam is determined by using related information of a downlink receive beam, so that the UE can efficiently determine spatial information of an uplink signal to be transmitted by the UE.