Wireless Node Reference Signal Phase Coordination

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Solution Overview

Problem

Existing wireless communication systems face challenges in coordinating interference alignment across multiple cells, particularly in scenarios with loose coordination and limited backhaul resources, leading to inefficiencies in interference suppression and scheduling of transmissions.

Innovation Solution

A method where a wireless node transmits a reference signal with a specific phase from multiple antennas, indicating desired radio conditions for reception, which is received by other nodes to facilitate interference alignment and scheduling, allowing for adaptive precoder weight selection to minimize interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If interference alignment is implemented across multiple cells, then interference suppression capability is improved, but coordination complexity and backhaul resource requirements increase

Engineering Contradiction:
Improveinterference suppression capabilityVSAvoidcoordination complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

A network node acts as an intermediary by receiving reference signals from wireless nodes, determining appropriate precoder weights for interfering transmissions, and transmitting control signals to coordinate interference alignment across cells. This intermediary approach enables distributed interference management without requiring direct complex coordination between all transmitting nodes

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

Wireless nodes transmit reference signals that provide feedback information about desired radio conditions and interference characteristics. The network node uses this feedback to determine precoder weights that align interference, creating a closed-loop system that adapts to changing channel conditions while maintaining coordination efficiency

Inventive Principle:
Principle #23Feedback

2Measurement precision

If reference signals are transmitted continuously for interference alignment, then interference management accuracy is improved, but network resource consumption increases

Engineering Contradiction:
Improveinterference management accuracyVSAvoidnetwork resource consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

Reference signal transmission is performed periodically or event-driven rather than continuously. The wireless node transmits reference signals at specific intervals or when channel conditions change, maintaining adequate measurement accuracy while significantly reducing network resource consumption compared to continuous transmission

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

Reference signals are transmitted in advance before actual data transmissions occur. This preliminary action allows the network node to determine appropriate precoder weights ahead of time, ensuring accurate interference management is ready when needed without requiring continuous signal transmission

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3259853B1Wireless node, radio node and methods for transmitting and receiving a reference signal
Publication Date: 2023.04.12 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3259853B1 patent drawingFigure 1
  • EP3259853B1 patent drawingFigure 2
  • EP3259853B1 patent drawingFigure 3

AI summary

A method in a first wireless node (120) for transmitting a reference signal is provided. The first wireless node (120) operates in a wireless communications network (100). The first wireless node (120) transmits the reference signal from at least two transmit antennas of the first wireless node (120). The reference signal is transmitted with a phase between the at least two transmit antennas indicating a desired phase related to radio conditions for reception of a transmission from a first radio node (1 11) at the first wireless node (120). The reference signal is to be received and taken into account by one or more other radio nodes (1 12) in the wireless communications network (100), e.g. when scheduling transmissions to other wireless nodes (122).