NOMA Constellation Configuration for Wireless Signal Demodulation
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Solution Overview
Problem
Current wireless communication systems face challenges in efficiently modulating and demodulating signals using non-orthogonal multiple access (NOMA) constellations, leading to high bit error rates and increased processing overhead due to significant bit differences between adjacent constellation points.
Innovation Solution
The method involves configuring NOMA constellations to maintain a single-digit bit difference between adjacent points, using techniques such as XNOR operations to generate bit sequences for combined constellation points, and employing bit-level gray converters to minimize signaling overhead and improve demodulation performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional NOMA constellation modulation is used, then spectral efficiency is improved through non-orthogonal multiple access, but bit error rate increases due to significant bit differences between adjacent constellation points
Solution Approach 1:
The patent applies parameter changes by modifying the bit mapping scheme for NOMA constellation points. Specifically, it changes the number of bits used to represent each constellation point from conventional multi-bit representations to single-bit representations. This parameter change in the signaling format reduces the bit difference between adjacent constellation points, thereby lowering the bit error rate while maintaining spectral efficiency through NOMA.
2Adaptability or versatility
If conventional NOMA constellation configuration is used, then multiple users can be served simultaneously, but processing overhead increases due to complex bit sequence management
Solution Approach 1:
The patent applies segmentation by dividing the bit sequence representation into individual single-bit segments for each constellation point. Instead of managing complex multi-bit sequences, each NOMA constellation point is represented by a single bit. This segmentation simplifies the bit sequence management process, reducing processing overhead while maintaining the ability to serve multiple users simultaneously through NOMA superposition.
Data Source
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AI summary
A method for receiving a signal by a first terminal in a wireless communication system supporting non-orthogonal multiple access (NOMA) according to an embodiment of the present invention comprises the steps of: receiving a NOMA signal in which signals for each of the first terminal and a second terminal belonging to the same NOMA pair are superposed; and demodulating the signal for the first terminal from the NOMA signal, using at least a part of a NOMA constellation which is configured by considering downlink transmission power and a modulation order for the second terminal, wherein only a bit corresponding to one digit is differently configured between the bit sequences of NOMA constellation points adjacent to each other in the NOMA constellation, and the complex coordinates (I, Q) of the NOMA constellation points are determined on the basis of a combination of downlink transmission power for the first terminal and the downlink transmission power for the second terminal.