Downlink Data Transmission via Antenna Group Selection

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Solution Overview

Problem

In high-speed wireless communication scenarios, the Doppler frequency offset causes significant challenges in frequency synchronization, leading to degraded downlink performance due to signal superposition from different directions of arrival, which existing pre-compensation methods struggle to address effectively across multiple terminals, impacting Quality of Service (QOS) and implementation complexity.

Innovation Solution

A downlink data transmission method that acquires status information on antenna groups with strong signals, enabling a selective downlink data transmission function based on frequency offset and signal quality thresholds to prevent inverse-phase superposition, ensuring precise data reception by selecting the appropriate antenna group for transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pre-compensation for frequency offset is applied to improve downlink performance, then signal quality improves for individual users, but implementation complexity and scheduling difficulty increase significantly for multiple terminals

Engineering Contradiction:
Improvedownlink performanceVSAvoidimplementation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the parameter of frequency offset compensation from a pre-processing step to a post-detection step. By measuring the actual frequency offset after signal reception and adjusting the detection timing accordingly, the system achieves frequency offset compensation without the complex pre-compensation scheduling required by prior art. This parameter change simplifies the overall system complexity while maintaining downlink performance.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If multiple antenna groups transmit downlink data simultaneously to serve more users, then system capacity increases, but signal superposition with different Doppler frequency offsets causes performance degradation

Engineering Contradiction:
Improvesystem capacityVSAvoidsignal quality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the terminal measures the frequency offset of received signals from multiple antenna groups and reports this information back to the base station. The base station then uses this feedback to adjust the detection timing for each antenna group, ensuring that signals with different Doppler frequency offsets are detected at appropriate times without causing performance degradation. This feedback loop enables simultaneous multi-antenna transmission while maintaining signal quality.

Inventive Principle:
Principle #23Feedback

3Reliability

If frequency offset measurement and selective antenna group transmission are implemented to improve signal quality, then communication quality improves, but measurement and control complexity increases

Engineering Contradiction:
Improvecommunication qualityVSAvoidmeasurement complexity
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent employs a self-service approach where the terminal autonomously performs frequency offset measurement on signals received from different antenna groups and determines which antenna group provides the best signal quality. The terminal then selects the optimal antenna group for data reception without requiring complex base station coordination or measurement. This self-service mechanism improves communication quality while minimizing measurement and control complexity.

Inventive Principle:
Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enhances communication quality by selectively enabling downlink data transmission on antenna groups with minimal frequency offset and optimal signal strength, thereby improving system performance and maintaining Quality of Service across multiple terminals.

Implementation Method 1

the requirement on frequency synchronization is much higher. In a case of a low center frequency, the influence of Doppler frequency offset caused by movement is not a challenge to Long Term Evolution (LTE) technology. However, in a case of high or ultrahigh center frequency, the Doppler frequency offset in the high-speed scenarios can seriously affect the system performance

Methodology Applied
Scientific EffectDoppler frequency offset: Doppler Effect

Data Source

PatentEP3451775B1Downlink data transmission method, apparatus and base station
Publication Date: 2021.02.24 ZTE CORP
  • EP3451775B1 patent drawingFigure 1
  • EP3451775B1 patent drawingFigure 2~3
  • EP3451775B1 patent drawingFigure 4

AI summary

Provided is a downlink data transmission method, apparatus and base station. The downlink data transmission method includes: transmitting, according to status information on whether or not one or more antenna group in an uplink activation set of a terminal perform downlink data transmission, downlink data to the terminal on an antenna group configured to transmit the downlink data in the uplink activation set. The solution determines an antenna group that actually transmits the downlink data in the uplink activation set of the terminal, and transmits the downlink data on the antenna group. This avoids the inverse-phase superposition of signals in transmission of downlink data which affects communication quality. The downlink data transmission method guarantees precise reception of data and communication quality between the base station and the terminal.