Tuneable N-Dimensional Constellation for Higher-Rate Demodulation
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Solution Overview
Problem
Existing modulation schemes in wireless communication, such as QPSK and 16-QAM, do not provide an acceptable rate under certain Signal to Noise Ratios (SNR) and require high demodulation complexity, while 8-QAM offers lower rates with comparable complexity.
Innovation Solution
A method and nodes that utilize a tuneable multi-dimensional constellation to transmit and receive N+1 bits, using a constellation tuning parameter to achieve higher rates than QPSK with reduced demodulation complexity, similar to or lower than 8-QAM.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If higher-order modulation schemes like 16-QAM or 8-QAM are used to increase transmission rate, then the achievable rate is improved, but the demodulation complexity increases
Solution Approach 1:
The patent extends the conventional 2-dimensional QAM constellation to N-dimensional constellations, where N > 2. This dimensional expansion allows encoding N+1 bits per modulation element, achieving higher transmission rates while maintaining demodulation complexity comparable to or lower than traditional 8-QAM or 16-QAM schemes.
Solution Approach 2:
The patent introduces a constellation tuning parameter that allows dynamic adjustment of the N-dimensional constellation structure. By changing this parameter, the system can optimize the balance between transmission rate and demodulation complexity for different channel conditions, achieving adaptive high-rate transmission without fixed high complexity.
2Device complexity
If QPSK modulation is used to maintain low demodulation complexity, then the demodulation complexity is reduced, but the transmission rate becomes unacceptable under certain SNR conditions
Solution Approach 1:
The patent transitions from 2-dimensional QPSK to N-dimensional constellations, enabling the system to achieve higher transmission rates (N+1 bits per symbol) while keeping demodulation complexity manageable through the structured approach to N-dimensional signal processing.
Solution Approach 2:
The patent employs dynamic constellation tuning through a configurable parameter that allows the system to adapt the N-dimensional constellation structure based on channel conditions. This enables the system to achieve higher rates than fixed QPSK while maintaining flexibility to adjust complexity based on operational requirements.
Data Source
AI summary
Disclosed is a method, performed by a transmit node, for transmitting N+1 bits to a receive node. N is a positive integer. The method comprises producing a modulation element by mapping the N+1 bits to a constellation point of a N-dimensional tuneable constellation, wherein the N-dimensional tuneable constellation is derived using a constellation tuning parameter. The method comprises determining, based on N, one or more physical resource elements for the modulation element. The method comprises transmitting, to the receive node, the modulation element, using the physical resource elements.