Multi-Datastream QAM Modulation for Single Cell Networks
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Solution Overview
Problem
In single cell network environments, existing hierarchical modulation and Dirty Paper Coding technologies fail to effectively bridge the performance gap between first and second data streams, leading to suboptimal reception performance for integrated multi-datastream transmission.
Innovation Solution
A modulation scheme that combines first and second bit streams to form symbols mapped into QAM modulation symbols, with constellations for both streams located in multiple quadrants, eliminating the energy disparity and improving bit error rate (BER) performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If hierarchical modulation or DPC modulation is used in single cell network environment, then integrated multi-datastream transmission can be achieved, but the BER performance of second data stream becomes unbearable due to energy disparity
Solution Approach 1:
The patent applies asymmetry principle by deliberately designing different constellation distribution patterns for first and second data streams. Specifically, constellations of the first data stream are distributed across multiple quadrants while constellations of the second data stream are concentrated in a single quadrant, creating an asymmetric structure that compensates for the energy disparity and improves BER performance of the second data stream.
Solution Approach 2:
The patent applies local quality principle by optimizing the constellation distribution specifically for the second data stream in the single quadrant where it has weaker energy. This localized optimization ensures that the second data stream's constellations are positioned to maximize detection reliability in its specific energy condition, rather than applying uniform distribution across all quadrants.
2Device complexity
If constellations of first data stream are located in same quadrant, then modulation simplicity is maintained, but BER performance difference between first and second data streams becomes apparent
Solution Approach 1:
The patent creates asymmetric constellation distributions where the first data stream uses multi-quadrant distribution and the second data stream uses single-quadrant concentration. This asymmetric design intentionally treats the two data streams differently to compensate for their inherent energy disparity, thereby achieving more equal BER performance while maintaining reasonable modulation complexity.
Data Source
AI summary
The present invention is related to integrated multi-datastream transmission technology, more particularly, to integrated multi-datastream modulation technology. According to one aspect of the present invention, there is provided a modulation equipment (10), including: a symbol integration means (101), configured to combine a first bit stream with a second bit stream to form a symbol to be modulated; a symbol mapping means (102), configured to map the symbol to be modulated into a QAM modulation symbol according to a set of predetermined mapping rules; wherein, in the set of predetermined mapping rules, multiple constellations corresponding to any first bit stream are located in at least two quadrants in the constellation diagram, while multiple constellations corresponding to any second bit stream are located in at least two quadrants in the constellation diagram. The integrated transmission of a first service data and a second service data (e.g., unicast service data and MBMS data) may be supported and has a better performance than the prior art especially in single cell scenario by using the method, equipment and device in the present invention.