Adaptive Modulation Control via Reception State Correction

Solution Overview

Problem

Conventional adaptive modulation systems face performance degradation due to propagation path estimation errors and inability to follow high-speed temporal variations, leading to unsuitable modulation parameter selection and subsequent deterioration in communication quality.

Innovation Solution

An adaptive modulation control system that measures reception states to correct propagation path information, allowing for the selection of modulation parameters corresponding to the probability of temporal variations, thereby reducing communication performance deterioration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional propagation path estimation methods are used, then the system is simple to operate, but propagation path estimation accuracy deteriorates under high-speed conditions

Engineering Contradiction:

Improvepropagation path estimation accuracyVSAvoidestimation system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The system performs preliminary propagation path estimation using pilot symbols before actual data transmission, and stores these estimation results for later correction. This preliminary action allows the system to prepare estimation data in advance, which is then refined using reception state measurements to improve accuracy without adding complex real-time processing during transmission.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system measures the reception state of actually received signals and uses this feedback to correct the preliminary propagation path estimation results. This feedback mechanism enables the system to adapt to temporal variations in the propagation path by comparing expected estimates with actual reception conditions, thereby improving estimation accuracy under high-speed conditions.

Inventive Principle:

Principle #23Feedback

2Speed

If linear extrapolation using pilot symbols is used, then temporal variations can be followed, but propagation path estimation accuracy deteriorates when variation exceeds following performance

Engineering Contradiction:

Improvetemporal variation tracking speedVSAvoidpropagation path estimation accuracy

Core Design Contradiction:

SpeedVSMeasurement precision

Solution Approach 1:

The reception state measurement acts as an intermediary between the preliminary propagation path estimation and the final corrected estimate. Instead of directly relying on extrapolation that may fail under high-speed conditions, the system uses reception state measurements as a mediator to correct estimation errors, thereby maintaining accuracy even when temporal variations exceed the following performance of simple extrapolation methods.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If modulation parameter selection is based on propagation path estimation, then communication efficiency is improved, but communication quality deteriorates due to estimation errors

Engineering Contradiction:

Improvecommunication efficiencyVSAvoidcommunication quality

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The system performs preliminary propagation path estimation using pilot symbols before actual data transmission, and stores these estimation results for later correction. This preliminary action allows the system to prepare estimation data in advance, which is then refined using reception state measurements to improve accuracy without adding complex real-time processing during transmission.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system measures the reception state of actually received signals and uses this feedback to correct the preliminary propagation path estimation results. This feedback mechanism enables the system to adapt to temporal variations in the propagation path by comparing expected estimates with actual reception conditions, thereby improving estimation accuracy under high-speed conditions.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS8185064B2Adaptive modulation control system and wireless communication apparatus

Publication Date: 2012.05.22 UERAN TECHNOLOGY LLC

AI summary

ObjectTo reduce deterioration of transmission quality under circumstances where the moving speed is high.Overcoming MeansAn adaptive modulation control apparatus for adaptively selecting a modulation parameter from among a plurality of modulation parameters determined based on a plurality of modulation schemes, coding rates of error correction or a combination thereof corresponding to a propagation path state is provided with a reception state measuring section (2) that measures a reception state of a signal received from a communicating apparatus, a correcting section (3) that makes a correction to change propagation path information indicative of a measurement result of the propagation path state based on the measured reception state, and a modulation parameter selecting section (4) that selects a modulation parameter corresponding to the corrected propagation path information.