NOMA Terminal Signal Detection With Power-Aware Modulation Mapping
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Solution Overview
Problem
In Non-Orthogonal Multiple Access (NOMA) systems, there is a need to improve signal demodulation precision and reduce interference for terminal apparatuses sharing the same resource.
Innovation Solution
A base station apparatus and terminal apparatus are designed to utilize modulation mapping techniques and interference suppression methods, including Non-Orthogonal Multiple Access (NOMA) modes, to enhance demodulation precision and throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple terminal apparatuses share the same resource in NOMA, then resource utilization efficiency is improved, but interference between signals increases and demodulation precision deteriorates
Solution Approach 1:
The base station segments the modulation signals by applying different modulation schemes (first modulation scheme for remote terminal, second modulation scheme for nearby terminal) and superimposing them with different power levels. The terminal apparatus segments the received signal by separating the desired signal from interference signals through blind detection of modulation schemes and selective demodulation, thereby resolving the interference caused by resource sharing.
2Temperature
If high power and low-rate MCS are assigned to remote terminal in NOMA, then coverage is improved, but throughput of the system deteriorates
Solution Approach 1:
The base station changes the modulation parameters by assigning different modulation schemes (first modulation scheme with lower order for remote terminal, second modulation scheme with higher order for nearby terminal) and different power levels. This parameter differentiation allows the remote terminal to receive signals with sufficient power for reliable demodulation while the nearby terminal can utilize higher rate modulation to maintain system throughput.
3Productivity
If low power and high-rate MCS are assigned to nearby terminal in NOMA, then throughput is improved, but signal quality for remote terminal deteriorates
Solution Approach 1:
The patent converts the harmful interference effect into a beneficial structure by deliberately superimposing the high-rate signal for the nearby terminal onto the low-rate signal for the remote terminal with controlled power levels. The remote terminal, being more sensitive due to distance, can still reliably detect its signal while the nearby terminal, with better channel conditions, can tolerate the interference and successfully decode its higher-rate signal through the interference structure.
Data Source
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AI summary
A signal that is transmitted to a terminal apparatus itself is demodulated with high precision, and throughput is improved. A terminal apparatus that communicates with a base station apparatus includes: a reception unit that receives downlink control information from the base station apparatus; and a signal detection unit that demodulates a signal that is transmitted to the terminal apparatus itself, based on first modulation mapping, and demodulates an interference signal based on second modulation mapping, in a case where information relating to a transmit power of the interference signal is included in the downlink control information. A base station apparatus that communicates with a terminal apparatus includes: a transmission unit that transmits a transmit signal at a different transmit power to each of a plurality of terminal apparatuses, in a case where the plurality of terminal apparatuses are multiplexed with the same resource, and a modulation unit that performs modulation using first modulation mapping for a terminal apparatus that has a minimum transmit power, and performs the modulation using second modulation mapping for other terminal apparatuses.