Downlink Uplink Reference Signal Association for 5G Positioning

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Solution Overview

Problem

Wireless communication systems, particularly in 5G and MIMO systems operating at high frequencies, face significant propagation loss issues due to the high frequency bands, which affect data transfer rates and positioning accuracy.

Innovation Solution

The solution involves associating a downlink reference signal with an uplink reference signal for transmission by user equipment, allowing for improved positioning accuracy by scheduling resources for both signals and transmitting an indication of their association, enabling the user equipment to transmit uplink reference signals on specific resources for positioning procedures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If beamforming is used to extend RF signal coverage and increase data rates, then signal strength and coverage are improved, but propagation loss remains severe at mmW frequencies

Engineering Contradiction:
Improvesignal strengthVSAvoidpropagation loss
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The patent combines downlink reference signals for positioning with uplink reference signals for transmission by user equipment. This merging allows the network to utilize both DL and UL signals for positioning purposes, thereby improving positioning accuracy while compensating for propagation losses at mmW frequencies through coordinated two-way signal exchange and beamforming.

Inventive Principle:
Principle #5Merging (Combining)

2Measurement precision

If multiple reference signals are scheduled for positioning procedures, then positioning accuracy is improved, but signaling overhead and system complexity increase

Engineering Contradiction:
Improvepositioning accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent enables reference signals to serve multiple functions simultaneously. Downlink reference signals are used both for traditional channel estimation purposes and for positioning measurements, while uplink reference signals serve both transmission and positioning functions. This multi-functionality improves positioning accuracy without proportionally increasing system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If uplink reference signals are transmitted by user equipment for positioning, then positioning accuracy is enhanced, but user equipment power consumption increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent implements partial uplink transmission by user equipment - only specific uplink reference signals are transmitted when needed for positioning procedures, rather than continuous transmission. The network schedules UL RS transmissions selectively based on positioning requirements, thereby achieving enhanced positioning accuracy while minimizing unnecessary power consumption at the user equipment.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3821656B1Associating a downlink reference signal for positioning of a user equipment with an uplink reference signal for transmission by the user equipment
Publication Date: 2024.03.13 QUALCOMM INC
  • EP3821656B1 patent drawingFigure 1
  • EP3821656B1 patent drawingFigure 2A
  • EP3821656B1 patent drawingFigure 2B

AI summary

In an embodiment, a network entity schedules, as part of a positioning procedure for a UE, a first set of resources for transmission of DL RS(s) by at least one BS to the UE. The network entity associates the DL RS(s) with UL RS(s) for transmission by the UE on a second set of resources to one or more BSs as part of the positioning procedure for the UE. The network entity transmits, to the UE, an indication of the association between the DL RS(s) and the UL RS(s). The UE receives the indication along with the DL RS(s) from the at least one BS. The UE transmits the UL RS(s) to the one or more BSs on the second set of resources in response to the received indication.