PDMA Signal Detection via Modulation Constellation Rotation

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Solution Overview

Problem

In the PDMA technology, the receiving end faces challenges in effectively detecting signals due to overlapping modulation constellation diagrams when multiple layers of data streams using the same modulation constellation and power pass through the same channel, leading to interference and reduced detection accuracy.

Innovation Solution

The method involves adjusting each layer of data modulation symbols on time-frequency resources using a modulation constellation rotating factor, determined by the number of non-zero elements in the encoding matrix, to ensure non-overlapping modulation constellation diagrams, and optionally adjusting power and amplitude to improve signal detection. This is achieved by determining the modulation constellation rotating factor using the formula exp(j*n*π*m*N) and applying it to each layer's data modulation symbols, where n=0, 1...N-1, and N is the number of data layers passing through the same channel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple layers of data streams use the same modulation constellation and power in PDMA, then the transmission resource utilization is improved, but the modulation constellation diagrams overlap causing detection difficulty at the receiving end

Engineering Contradiction:
Improvetransmission resource utilizationVSAvoidsignal detection difficulty
Core Design Contradiction:
ProductivityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent applies local quality by assigning different modulation constellations to different data layers. Specifically, the first data layer uses a first modulation constellation while the second data layer uses a second modulation constellation that is different from the first. This allows each layer to have distinct constellation diagrams that do not overlap, enabling the receiving end to distinguish between layers and accurately detect signals, thus resolving the detection difficulty while maintaining efficient resource utilization.

Inventive Principle:
Principle #3Local quality

2Device complexity

If multiple layers of data streams use the same modulation constellation, then the encoding complexity is reduced, but the detection accuracy at the receiving end deteriorates due to overlapping constellation diagrams

Engineering Contradiction:
Improveencoding complexityVSAvoiddetection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent implements local quality by assigning different modulation constellations to different data layers. The first data layer is modulated using a first modulation constellation while the second data layer uses a second modulation constellation that is distinct from the first. This differentiation ensures that the modulation constellation diagrams for different layers do not overlap, enabling the receiving end to accurately detect and distinguish between layers, thereby improving detection accuracy without significantly increasing encoding complexity.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If the same power is used for all data layers, then the transmission simplicity is maintained, but the signal detection performance deteriorates when layers pass through the same channel

Engineering Contradiction:
Improvetransmission simplicityVSAvoidsignal detection performance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies local quality by assigning different modulation constellations to different data layers, which allows the receiving end to distinguish between layers even when they pass through the same channel. This approach maintains transmission simplicity by keeping the power levels uniform across layers while improving signal detection performance through constellation differentiation, thus resolving the contradiction between ease of operation and reliability.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3282625B1Method and device for detecting data transmission and received signals
Publication Date: 2019.05.08 CHINA ACAD OF TELECOMM TECH
  • EP3282625B1 patent drawingFigure 1~2A
  • EP3282625B1 patent drawingFigure 2B~3
  • EP3282625B1 patent drawingFigure 4~5

AI summary

The embodiments of the present application relate to the technical field of wireless communications, and in particular to a method and device for detecting data transmission and received signals, which are used for solving the problem in the prior art that it is disadvantageous for signal detection due to the fact that when a receiving end is detected in the scenario that each column of an encoding matrix of PDMA corresponds to one layer of data stream, multiple layers of data modulation symbols are superposed. The embodiments of the present application adjust various layers of data modulation symbols modulated by an initial modulation constellation diagram according to a modulation constellation rotating factor corresponding to various layers of data modulation symbols, so that the modulation constellation diagrams corresponding to various layers of data modulation symbols are not superposed, thereby preventing the problem of being disadvantageous for signal detection of a receiving end due to the fact that multiple layers of data modulation symbols are superposed in the scenario that each column of the encoding matrix of PDMA corresponds to one layer of data stream; and further improving the system performance.