Wireless Signal Processor Windowing and Filtering for Inter-Carrier Interference
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Solution Overview
Problem
The integration of 4G and 5G wireless communication systems faces challenges due to significant inter-carrier interference (ICI) caused by frequency misalignment and differences in waveform and carrier spacing, leading to degraded signal quality in Orthogonal Frequency Division Multiple Access (OFDMA) systems.
Innovation Solution
A wireless communication apparatus and method that employs a signal modulator, processor, and transmitter with window and filter modules to perform iterative out-of-band power leakage suppression algorithms, estimating window and filter characteristic functions to generate modulated signals with reduced ICI by performing windowing and filtering operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If OFDM systems use multiple sub-carriers for data transmission, then spectral efficiency is improved, but inter-carrier interference (ICI) occurs due to slow spectral sidelobe decay
Solution Approach 1:
The patent extracts and removes the harmful spectral sidelobes that cause inter-carrier interference by applying windowing functions and filtering operations to the OFDM signal, separating the useful signal from the harmful components
Solution Approach 2:
The patent changes the signal parameters by applying different windowing functions (e.g., Hann, Hamming, Blackman) and filtering operations to modify the spectral characteristics of the OFDM signal, reducing sidelobe levels while maintaining main lobe integrity
2Adaptability or versatility
If 4G and 5G systems share the same frequency band, then system compatibility is improved, but signal quality deteriorates due to frequency misalignment and carrier spacing differences
Solution Approach 1:
The patent introduces windowing functions and filtering operations as intermediary processing steps between signal generation and transmission, acting as mediators to reduce interference between 4G and 5G signals sharing the same frequency band
Solution Approach 2:
The patent applies different windowing functions and filtering parameters to different signal components and frequency regions, optimizing each local region's signal quality while maintaining overall system compatibility
3Adaptability or versatility
If different carrier spacing is used between 4G and 5G systems, then system flexibility is improved, but inter-carrier interference increases due to frequency misalignment
Solution Approach 1:
The patent employs dynamic windowing and filtering operations that can be adaptively adjusted based on the specific carrier spacing and frequency alignment conditions, allowing the system to optimize performance for different 4G and 5G configurations
Data Source
AI summary
In one exemplary embodiment, a wireless communication apparatus transmitting data by using several sub-carriers. The wireless communication apparatus comprises a signal modulator, a signal processor, a storage, a computing processor, and a transmitter. The signal modulator generates a modulated signal in time domain based on the data. The signal processor performs signal processing on the modulated signal, and comprises a window module and a filter module. The window module performs windowing operation on the modulated signal to generate a window-operated signal. The filter module performs filtering operation on the window-operated signal to generate a transmitting signal in time domain. The computing processor performs operations of setting up the window module and the filter module according to a window characteristic function and a filter characteristic function. The transmitter transmits the transmitting signal.