Hybrid FQAM Signal Mapping for Cell-Edge Interference
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Solution Overview
Problem
Wireless communication systems face challenges in providing improved spectral efficiency and channel capacity, especially for users with low signal-to-noise ratios (SNR) at the cell edge, due to interference from adjacent cells.
Innovation Solution
The method involves using multiple antennas to transmit and receive signals using a hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM) mode, where symbols are mapped to specific frequency tones, creating a non-Gaussian interference characteristic, and utilizing tone location information for efficient demodulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional QAM modulation is used for signal transmission, then spectral efficiency is improved, but interference characteristics remain Gaussian and service quality for cell-edge users deteriorates
Solution Approach 1:
The patent changes the interference characteristic parameter from Gaussian to non-Gaussian by introducing FSK-based tone activation. Specifically, it maps QAM signals to frequency tones selectively activated by FSK signals, transforming the statistical properties of interference to improve service quality for cell-edge users while maintaining spectral efficiency
2Productivity
If multiple frequency tones are activated for signal transmission, then channel capacity increases, but interference management becomes more complex
Solution Approach 1:
The patent employs feedback mechanisms where tone location information is detected and used to control the activation state of frequency tones. This feedback loop enables dynamic interference management by adjusting which tones are activated based on detected tone locations, simplifying the management of multiple frequency tones while maintaining high channel capacity
3Reliability
If FSK and QAM are combined for modulation, then non-Gaussian interference characteristic is achieved, but demodulation complexity increases
Solution Approach 1:
The patent segments the demodulation process into two distinct stages: first detecting tone location information from FSK signals, then using this information to guide QAM signal demodulation. This segmentation reduces overall demodulation complexity by breaking down the complex FQAM demodulation into manageable sequential steps rather than attempting simultaneous processing
Data Source
AI summary
A method and a device for transmitting and receiving a signal on the basis of multiple antennas are provided.A transmitting device may include a radio frequency (RF) module transmitting a quadrature amplitude modulation (QAM) signal of a first symbol corresponding to a hybrid frequency shift keying and quadrature amplitude modulation (FQAM) mode and transmitting a QAM signal of a second symbol corresponding to a QAM mode through a second antenna; and a modulation module mapping the QAM signal of the first symbol to one frequency tone among the preset number of frequency tones according to a frequency shift keying (FSK) signal of the first symbol and mapping the second symbol to the frequency tone to which the first symbol is mapped.