Cross-Shaped Symbol Mapping for Lower-BER Modulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current communication systems employing iterative error correction codes face challenges in achieving Shannon's limit for error-free transmission, particularly in reducing bit error rates (BER) and signal-to-noise ratio (SNR), as existing symbol mapping and modulation techniques do not effectively optimize constellation patterns for improved throughput and error reduction.
Innovation Solution
The implementation of a cross-shaped constellation pattern derived from a rectangle-shaped constellation, where subsets of constellation points are rearranged to reduce vector magnitudes and maintain symmetry, is used in communication devices to enhance symbol mapping and de-mapping processes, thereby improving BER and SNR performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional symbol mapping and modulation techniques are used, then the communication system operates with standard constellation patterns, but the bit error rate remains higher and Shannon's limit cannot be achieved
Solution Approach 1:
The conventional rectangular constellation is segmented into multiple subsets of constellation points. Each subset is independently arranged to optimize specific performance metrics such as vector magnitude distribution and symmetry properties, allowing the system to achieve both lower BER and maintained throughput
Solution Approach 2:
The patent introduces asymmetric arrangements within constellation subsets, where points are positioned with different weights and magnitudes relative to the origin. This asymmetric positioning optimizes the distribution of vector magnitudes to reduce error rates while maintaining overall system throughput through careful balance of the constellation structure
2Productivity
If the signal-to-noise ratio is reduced to increase throughput, then more data can be transmitted, but transmission errors increase
Solution Approach 1:
Different subsets of constellation points are assigned different local qualities in terms of their vector magnitudes and positions. This allows the system to optimize specific regions of the constellation for noise resilience while maintaining overall high throughput by distributing data across multiple subsets with varying robustness characteristics
3Reliability
If constellation points are rearranged to reduce vector magnitudes for error reduction, then bit error rate improves, but the complexity of symbol mapping increases
Solution Approach 1:
The constellation subsets are pre-configured with optimized point arrangements during system initialization or design phase. This preliminary arrangement of points with reduced vector magnitudes and optimized symmetry properties eliminates the need for complex real-time calculations during symbol mapping, reducing operational complexity while maintaining error reduction benefits
Data Source
AI summary
The present disclosure presents symbol mapping for any desired error correction code (ECC) and/or uncoded modulation. A cross-shaped constellation is employed to perform symbol mapping. The cross-shaped constellation is generated from a rectangle-shaped constellation. Considering the rectangle-shaped constellation and its left hand side, a first constellation point subset located along that left hand side are moved to be along a top of the cross-shaped constellation while a second constellation point subset located along that left hand side are moved to be along a bottom of the cross-shaped constellation. For example, considering an embodiment having four constellation point subsets along the left hand side of the rectangle-shaped constellation, two of those subsets are moved to be along the top of the cross-shaped constellation while two other subsets of the constellation points along the left hand side are moved to be along the bottom of the cross-shaped constellation.