Terminal Apparatus CSI Feedback via Segmented Reference Signals

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Solution Overview

Problem

In communication systems like LTE, the existing method of reporting reception quality information is one-way and inefficient, leading to disturbances in transmission efficiency.

Innovation Solution

The system allows for efficient reporting of reception quality information by using multiple downlink reference signals and subframe sets to calculate and feedback channel state information, enabling flexible periodic and aperiodic feedback configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the same frequencies are used between adjacent cells or sectors, then frequency utilization efficiency is improved, but interference occurs to terminal apparatus in cell edge region

Engineering Contradiction:
Improvefrequency utilization efficiencyVSAvoidinterference to terminal apparatus
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The invention segments the downlink reference signals into multiple types (first downlink reference signal and second downlink reference signal) and segments subframes into different sets (first subframe set and second subframe set). This segmentation allows different reference signals to be transmitted in different subframe sets, enabling the terminal to measure and report channel state information for each segment separately, thus managing interference while maintaining frequency reuse

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces dynamic adaptability by allowing flexible configuration of subframe sets and reference signal parameters. The base station can dynamically adjust which reference signals are transmitted in which subframe sets based on interference conditions and traffic requirements, enabling the system to adaptively balance frequency utilization efficiency and interference management

Inventive Principle:
Principle #15Dynamics

2Device complexity

If one-way reporting method is used for reception quality information, then system complexity is reduced, but transmission efficiency deteriorates

Engineering Contradiction:
Improvereporting system complexityVSAvoidtransmission efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The invention implements a feedback mechanism where the terminal apparatus measures downlink reference signals, computes channel state information (including CQI, PMI, and RI), and reports this information back to the base station. The base station uses this feedback to adaptively adjust downlink transmission parameters such as modulation and coding scheme, spatial multiplexing rank, and precoding, thereby improving transmission efficiency through closed-loop control

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The invention introduces periodic reporting where the terminal apparatus reports channel state information at regular intervals configured by the base station. This periodic feedback mechanism ensures that the base station receives up-to-date channel information without requiring continuous reporting, thus balancing transmission efficiency improvement with system complexity management

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP2696618B1Terminal apparatus, base station apparatus and communication methods
Publication Date: 2021.06.09 SHARP KK
  • EP2696618B1 patent drawingFigure 1
  • EP2696618B1 patent drawingFigure 2
  • EP2696618B1 patent drawingFigure 3

AI summary

Provided is a terminal apparatus which performs communication with a base station apparatus. The terminal apparatus includes: a receiving unit which receives a plurality of channel state information reference signals; a channel state information generating unit which generates a plurality of channel state information by referring to each of the plurality of channel state information reference signals; and a report transmitting unit which reports each of the plurality of channel state information to the base station apparatus.