Rank Indicator Adaptation for MIMO Throughput

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Solution Overview

Problem

In wireless communication networks, the maximum number of MIMO data streams cannot always be sent due to interference, noise, and other issues, leading to suboptimal data throughput, as devices prioritize reporting high CQI values over RI values, potentially underutilizing available capacity.

Innovation Solution

A telecommunication device adapively reports an inflated RI value to the base station when the error rate is below an acceptable threshold, allowing the base station to increase the number of MIMO data streams, thereby enhancing data throughput.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If devices prioritize reporting high CQI values over RI values, then signal quality indication is improved, but data throughput is reduced due to underutilization of available MIMO capacity

Engineering Contradiction:

Improvesignal quality indicationVSAvoiddata throughput

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent changes the Rank Indicator parameter from its conventional value to an inflated value based on channel conditions and error rate thresholds. When the error rate is below a threshold, the device reports a higher RI than actually decoded, inducing the base station to transmit more data streams and thereby increasing throughput while maintaining signal quality indication accuracy

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent makes the RI reporting dynamic by adapting it to current channel conditions and error rates. The device dynamically adjusts the reported RI value based on whether the error rate is below or above a threshold, allowing the system to optimize throughput in good conditions while maintaining reliability in poor conditions

Inventive Principle:

Principle #15Dynamics

2Productivity

If the number of MIMO data streams is increased to improve throughput, then data throughput is improved, but decoding reliability deteriorates due to interference and noise

Engineering Contradiction:

Improvedata throughputVSAvoiddecoding reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent implements feedback control by monitoring the error rate of decoded data streams and using this information to adjust the RI reporting. The base station receives feedback about channel conditions and error rates, allowing it to adapt the number of data streams to maintain reliability while maximizing throughput

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent applies partial action by transmitting only the number of data streams that can be reliably decoded under current conditions. When error rates are low, the system uses excessive action by reporting inflated RI values to induce more streams, but only when channel conditions support it

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS10153888B1Rank indicator adaptation based on downlink error rate

Publication Date: 2018.12.11 T MOBILE US INC

AI summary

A method of inducing increased throughput to a telecommunication device, in which the telecommunication device sets a rank indicator (RI) based on a number of multiple-input multiple-output (MIMO) data streams received and decoded from a base station, determines an error rate of the decoded MIMO data streams, and increases the RI when it is less than a maximum RI and the error rate is less than an RI increase threshold. The RI is reported from the telecommunication device to the base station, which uses the increased RI to increase the number of MIMO data streams it sends to the telecommunication device.