Pair-Wise Symbol Correlated QPSK for Receiver Sensitivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current modulation formats in ultra long-haul transmission systems, such as BPSK and QPSK, have limitations in receiver sensitivity, leading to reduced transmission distances and increased energy consumption, necessitating a more efficient modulation format.
Innovation Solution
A pair-wise symbol correlated quadrature phase shift keying (QPSK) modulation format is introduced, which improves receiver sensitivity by correlating neighboring symbols and maintaining compatibility with standard QPSK transceivers, allowing for longer transmission distances and reduced energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If BPSK or QPSK modulation formats are used in ultra long-haul transmission systems, then the transceiver design is simple and compatible with standard constellations, but the receiver sensitivity is limited and transmission distance is reduced
Solution Approach 1:
The modulation format segments the data stream into pairs of symbols, applying correlation processing to each pair independently. This segmentation allows the system to maintain compatibility with standard QPSK transceivers while improving receiver sensitivity through pairwise correlation, resolving the contradiction between simplicity and performance
Solution Approach 2:
The invention creates a modulation format that is universal enough to work with standard QPSK transceivers while adding correlation processing that improves sensitivity. The format can be implemented in existing systems without requiring completely new hardware, making it broadly applicable while solving the receiver sensitivity problem
2Productivity
If spectral efficiency is increased to maximize capacity, then the transmission capacity improves, but the maximum achievable distance drops dramatically
Solution Approach 1:
The invention changes the modulation parameters by introducing correlation between pairs of symbols, achieving 1.5 b/s per polarization spectral efficiency. This parameter change allows the system to maintain high capacity while improving receiver sensitivity, thereby extending transmission distance without sacrificing capacity
3Adaptability or versatility
If multiple modulation formats and constellation sizes are supported in transceivers, then the adaptability to different transmission distances improves, but the design and operation cost increases significantly
Solution Approach 1:
The invention segments the modulation approach by using fixed QPSK constellations with correlation processing rather than variable constellation sizes. This segmentation allows transceivers to maintain a fixed, simple design while achieving adaptability through the correlation processing that improves sensitivity for longer distances
Solution Approach 2:
The invention introduces dynamic correlation processing between symbol pairs that can be activated or deactivated based on transmission distance requirements. This dynamic approach allows a single transceiver design to adapt to different transmission conditions without requiring multiple hardware configurations, resolving the contradiction between adaptability and complexity
Data Source
AI summary
The invention is directed to a novel computer implemented method for finding a modulation format that has better receiver sensitivity than modulation formats that are currently being used, with a correlated symbol modulation in which neighboring symbols are coded and decoded together to increase receiver sensitivity.