Aperiodic CSI-RS Resource Reservation via RRC Signaling

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Solution Overview

Problem

Conventional LTE systems do not support the reservation and transmission of Channel State Information-Reference Signals (CSI-RS) resources for aperiodic CSI-RS transmission, leading to difficulties for user equipment (UE) in identifying CSI-RS resources, which hampers proper aperiodic CSI-RS performance.

Innovation Solution

The proposed solution involves reserving CSI-RS resources by the base station (BS) for aperiodic CSI-RS transmission, using reserved resources to transmit aperiodic CSI-RS, and providing reservation information through higher layer signaling, such as RRC signaling, to enable the UE to detect and receive aperiodic CSI-RS correctly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional LTE standards are used for CSI-RS transmission, then periodic CSI-RS transmission is supported, but aperiodic CSI-RS transmission cannot be properly performed due to lack of resource reservation support

Engineering Contradiction:

Improveaperiodic CSI-RS transmission capabilityVSAvoidCSI-RS resource identification reliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The base station performs preliminary reservation of CSI-RS resources before aperiodic CSI-RS transmission. The reservation information is configured in advance through higher layer signaling (RRC signaling), so that when aperiodic CSI-RS needs to be transmitted, the UE can immediately identify the pre-reserved resources without ambiguity, enabling reliable aperiodic transmission while maintaining periodic transmission compatibility

Inventive Principle:

Principle #10Preliminary action

2Adaptability or versatility

If aperiodic CSI-RS transmission is implemented without resource reservation, then transmission flexibility is improved, but UE's ability to identify CSI-RS resources deteriorates

Engineering Contradiction:

Improvetransmission flexibilityVSAvoidCSI-RS resource identification difficulty

Core Design Contradiction:

Adaptability or versatilityVSDifficulty of detecting and measuring

Solution Approach 1:

Reservation information serves as an intermediary between the base station's resource allocation decisions and the UE's resource identification process. This intermediary carries essential information about pre-reserved CSI-RS resources through higher layer signaling, allowing the UE to correctly identify and measure aperiodic CSI-RS resources without direct real-time coordination, thus maintaining both flexibility and detectability

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentEP3624385B1Base station, user equipment, and method of CSI-RS transmission

Publication Date: 2022.07.06 NTT DOCOMO INC

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AI summary

A method of Channel State Information Reference Signal (CSI-RS) transmission from a base station (BS) to a user equipment (UE) includes reserving, with the BS, a CSI-RS resource used for aperiodic CSI-RS transmission in subframes transmitted from the BS, transmitting, from the BS to the UE, reservation information indicating the CSI-RS resource via higher layer signaling, and transmitting, from the BS to the UE, the a periodic CSI-RS using the CSI-RS resource.