Base Station RI Bit Number Determination for MIMO Compatibility

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In the context of LTE networks, determining the correct rank indication (RI) bit number for MIMO functions between base stations and user equipment is challenging, leading to incorrect decoding and impaired MIMO functionality due to differing interpretations based on varying release versions and capabilities.

Innovation Solution

A method where the base station determines and sends indication information to the user equipment based on the correspondence between its release version and the user equipment's capabilities, ensuring both parties agree on the RI bit number, using CQI report configuration information and carrier aggregation indications to align their understanding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the base station and user equipment use different release versions or capability interpretations to determine RI bit number, then each device can operate according to its own specifications, but the RI decoding becomes incorrect and MIMO functionality is impaired

Engineering Contradiction:
Improvecompatibility across release versionsVSAvoidRI decoding accuracy
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The base station performs preliminary determination of the RI bit number based on the user equipment's category and MIMO capability before actual RI transmission. This advance preparation ensures both the base station and user equipment use the same bit number for RI encoding and decoding, preventing interpretation conflicts across different release versions while maintaining reliable communication

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent dynamically adjusts the RI bit number parameter based on the user equipment's category and MIMO capability. By changing this critical parameter according to device specifications, the system ensures compatibility across different release versions while maintaining accurate RI decoding, thus resolving the contradiction between adaptability and reliability

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If the RI bit number is determined based on user equipment category and MIMO capability, then accurate decoding is achieved, but additional determination steps and information exchange are required

Engineering Contradiction:
ImproveRI bit number determination accuracyVSAvoiddetermination process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The user equipment provides its own category and MIMO capability information to the base station, enabling the base station to autonomously determine the appropriate RI bit number. This self-service approach achieves accurate RI bit number determination while minimizing the need for complex centralized control or additional signaling overhead, thus balancing precision with complexity

Inventive Principle:
Principle #25Self-service

3Loss of information

If the base station sends indication information about RI bit number determination basis, then user equipment can correctly determine the bit number, but additional signaling overhead is introduced

Engineering Contradiction:
ImproveRI bit number understanding alignmentVSAvoidsignaling overhead
Core Design Contradiction:
Loss of informationVSQuantity of substance

Solution Approach 1:

The patent leverages existing CQI report configuration information to convey the determination basis for RI bit number. By making this existing signaling structure multi-functional, the system achieves alignment between base station and user equipment on RI bit number interpretation without introducing separate dedicated signaling, thus minimizing overhead while preventing information loss

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

Data Source

PatentEP3859993B1Method for determining rank indication ri bit number, base station, and terminal
Publication Date: 2023.08.23 HUAWEI TECH CO LTD

AI summary

The present invention provides a method for determining a rank indication RI bit number, a base station, and a terminal. The method includes: determining, by a base station, indication information according to a correspondence between a terminal and the base station and a multi-input multi-output MIMO capability of the terminal, where the indication information includes information used by the terminal for determining a bit number occupied for sending a RI; and sending, by the base station, the indication information to the terminal, so that the terminal determines, according to the indication information, the bit number occupied for sending the RI. In the present invention, the UE and the base station agree on understanding of the bit number occupied by RI information.