NOMA Bit-Level Layer Mapping for Gray Constellation Errors
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Solution Overview
Problem
Current wireless communication systems face challenges in efficiently transmitting downlink signals to multiple User Equipments (UEs) using Non-Orthogonal Multiple Access (NOMA), particularly in maintaining Gray mapping features on composite constellations, which leads to errors due to differing power levels between UEs.
Innovation Solution
The method involves performing bit-level layer mapping and Gray conversion before generating modulation symbols, allowing for efficient NOMA transmission by superposing constellations for UEs with different power levels, ensuring accurate bit sequence differentiation and error reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional NOMA transmission is performed without bit-level layer mapping, then transmission simplicity is maintained, but Gray mapping features are lost leading to increased errors due to differing power levels between UEs
Solution Approach 1:
The patent applies preliminary action by performing bit-level layer mapping and Gray conversion before generating modulation symbols. This preprocessing step ensures that bits are properly differentiated and mapped to constellation points before the superposition of different power levels, preventing the loss of Gray mapping features and reducing errors in NOMA transmission.
2Reliability
If bit-level layer mapping is performed before modulation symbol generation, then Gray mapping is maintained on composite constellations, but processing complexity increases
Solution Approach 1:
The patent applies preliminary action by performing bit-level layer mapping and Gray conversion before generating modulation symbols. This preprocessing step ensures that bits are properly differentiated and mapped to constellation points before the superposition of different power levels, preventing the loss of Gray mapping features and reducing errors in NOMA transmission.
3Reliability
If superposition of constellations with different power levels is performed without Gray conversion, then NOMA transmission is simplified, but bit sequence differentiation becomes inaccurate leading to errors
Solution Approach 1:
The patent applies preliminary action by performing bit-level layer mapping and Gray conversion before generating modulation symbols. This preprocessing step ensures that bits are properly differentiated and mapped to constellation points before the superposition of different power levels, preventing the loss of Gray mapping features and reducing errors in NOMA transmission.
Data Source
AI summary
The method, according to one embodiment of the present invention, by which in a wireless communication system a base station transmits signals to a plurality of terminals on the basis of non-orthogonal multiple access (NOMA), comprises the steps of: mapping first information bits for a first terminal and second information bits for a second terminal onto a first layer for the NOMA; modulating the first information bits and the second information bits which have been mapped on the first layer; and transmitting modulation symbols, which have been generated as a result of the modulation, to the first terminal and the second terminal, wherein the base station may map the first information bits and the second information bits onto the first layer, at a bit level before the modulation symbols have been generated.