QAM Bit Reliability Balance via Location Exchange
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In communication systems using Quadrature Amplitude Modulation (QAM), the reliability of different bits within a symbol becomes uneven after multiple re-transferring processes, leading to reduced overall data reliability and decoder performance, as existing methods require storing multiple constellation figures to maintain bit reliability.
Innovation Solution
A data re-transferring method that exchanges the location of bits within a symbol before each re-transferring process, using a single constellation figure, thereby maintaining bit reliability balance and reducing storage requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple constellation figures are stored to maintain bit reliability during re-transferring processes, then bit reliability consistency is improved, but storage requirements increase
Solution Approach 1:
The patent segments the bit positions within a symbol into different groups (e.g., first bits and second bits in 16-QAM) and applies different transformation modes to different segments. This allows the system to maintain bit reliability consistency by treating different bit positions differently, while still using a single constellation figure, thus reducing storage requirements.
Solution Approach 2:
The patent changes the transformation mode parameter based on the re-transferring count to maintain bit reliability. By dynamically adjusting which bits are transformed and which are kept original according to a predetermined transformation mode, the system achieves reliable data transmission without needing to store multiple constellation figures.
2Reliability
If bit locations are transformed before modulation to maintain reliability, then decoder performance is improved, but system complexity increases
Solution Approach 1:
The patent performs bit location transformation before modulation as a preliminary action. By pre-processing the bits according to a predetermined transformation mode before the actual modulation occurs, the system improves decoder performance without adding complex real-time processing requirements during transmission.
Solution Approach 2:
The patent employs periodic transformation modes that cycle through different bit transformation patterns. This periodic approach simplifies the system design by using repeating patterns rather than requiring complex adaptive algorithms, thereby improving decoder performance while maintaining manageable system complexity.
Data Source
AI summary
The present invention discloses a data re-transferring method based on bit transformation in a communication system which adopts a high order modulation and supports a re-transferring mechanism. The method includes the processes of: exchanging the location of each bit modulated to a symbol in a constellation figure used in Quadrature Amplitude Modulation (QAM) according to a selected transformation mode; mapping re-transferred data to each bit modulated to a symbol in a constellation figure of which the location has been exchanged; performing the QAM of the re-transferred data. With the method, storage amount can be decreased, balance of reliability of bits within the same data symbol after multiple re-transferring processes can be ensured, in addition, performance of the decoder and reliability of data transmission can be improved.