Filter Bank Segmentation for Multicarrier Processing Efficiency
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Solution Overview
Problem
Current filter banks, particularly in multicarrier modulation schemes, face inefficiencies in processing and computational complexity, limiting their spectral efficiency and performance in applications like 5G communications.
Innovation Solution
The proposed solution involves a synthesis and analysis filter bank configuration with a transform module, filter modules, and parallel/serial modules, utilizing orthogonal prototype filters and polyphase decomposition to optimize signal processing, and employing FFT/IFFT algorithms for efficient discrete Fourier transforms, along with lattice structures and lifting steps to reduce computational complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional filter banks are used in multicarrier modulation schemes, then implementation is straightforward, but spectral efficiency is limited and processing efficiency is insufficient
Solution Approach 1:
The filter bank is segmented into analysis filter bank and synthesis filter bank with distinct functional modules. Each filter bank is further divided into multiple filter modules that process different subcarriers independently, enabling parallel processing and improving overall processing efficiency while maintaining manageable complexity through modular architecture.
Solution Approach 2:
The patent transitions from traditional time-domain filtering to frequency-domain processing using FFT/IFFT algorithms. By transforming the filter bank operation into the frequency domain, the system achieves O(N log N) complexity instead of O(N^2), significantly improving processing efficiency while reducing computational burden.
2Productivity
If traditional OFDM with cyclic prefix is used, then implementation is simple, but spectral efficiency is not maximized
Solution Approach 1:
The patent extracts and removes the cyclic prefix component from the OFDM structure, replacing it with a filter bank-based approach. This extraction eliminates the spectral inefficiency caused by the cyclic prefix while maintaining the robustness of multicarrier modulation, thereby improving spectral efficiency without overly complicating the implementation.
Solution Approach 2:
The system changes the fundamental parameter of how subcarriers are orthogonalized - from time-domain cyclic prefix insertion to frequency-domain filter bank processing. This parameter change enables continuous spectral utilization without the guard intervals required by traditional OFDM, achieving higher spectral efficiency while keeping implementation feasible through standardized FFT operations.
3Productivity
If filter banks with high spectral efficiency are implemented, then processing performance improves, but computational complexity increases
Solution Approach 1:
The patent substitutes direct time-domain filtering operations with frequency-domain FFT/IFFT-based processing. This substitution replaces computationally intensive convolution operations with efficient fast Fourier transform algorithms, reducing the computational complexity from O(N^2) to O(N log N) while maintaining or improving spectral efficiency through optimal filter design.
Solution Approach 2:
The filter bank structure is designed to serve multiple functions simultaneously: it performs subcarrier modulation, spectral shaping, and interference suppression all within a unified framework. By making the filter bank multi-functional, the system achieves high spectral efficiency without requiring separate processing stages, thereby reducing overall computational complexity.
Data Source
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AI summary
The disclosure refers to a synthesis filter bank, comprising: a transform module which is configured to receive a plurality of input signals, transform the plurality of input signals, and output a plurality of transformed signals, a plurality of filter modules, which are coupled to the transform module, and wherein each filter module of the plurality of filter modules is configured to receive two transformed signals from the transform module, process the two received transformed signals and output two processed signals, and a parallel-to-serial module which is coupled to the plurality of filter modules and which is configured to receive the processed signals from the plurality of filter modules, combine the received processed signals and output a combined signal. Furthermore, an analysis filter bank, a filter bank and methods for operating a synthesis filter bank and for operating an analysis filter bank are disclosed.