WOLA Channelizer Architecture for Lower-Complexity FDMA Processing

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Solution Overview

Problem

Fast-Fourier Transform (FFT)-based filter banks in multiple-channel FDMA receivers are computationally intensive and face difficulties as data rates increase, requiring more efficient channelization methods to manage signal processing in real-time.

Innovation Solution

A channelizer system incorporating a window buffer, weighting logic, time-folding logic, and discrete Fourier Transform (DFT) processes, along with overlap-add (OLA) logic and phase adjustments, to efficiently channelize and filter signals, reducing computational burden and resource usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If FFT-based filter banks are used for channelization in multiple-channel FDMA receivers, then real-time signal processing capability is achieved, but computational complexity and resource consumption increase significantly

Engineering Contradiction:
Improvereal-time signal processing capabilityVSAvoidcomputational complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent divides the wideband signal into multiple narrowband sub-bands using filter banks, where each sub-band is processed independently. This segmentation allows parallel processing of multiple channels simultaneously, achieving real-time performance while distributing computational load across multiple simpler filter operations rather than one complex full-band FFT operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies windowing functions to signal blocks before FFT processing to reduce spectral leakage and improve frequency resolution. This preliminary action prepares the data in advance, reducing the need for iterative adjustments and improving the efficiency of subsequent processing operations.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If simple data rates increase in FFT-based filter banks, then channel capacity improves, but technical difficulties and processing challenges arise

Engineering Contradiction:
Improvechannel capacityVSAvoidprocessing challenges
Core Design Contradiction:
ProductivityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent transforms the time-domain signal into the frequency domain using FFT, adding a frequency dimension to the processing. This allows simultaneous analysis of multiple frequency channels, increasing channel capacity while managing complexity through the structured frequency-domain representation that separates different signal components.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS10879876B2Resource conserving weighted overlap-add channelizer
Publication Date: 2020.12.29 HUGHES NETWORK SYST
  • US10879876B2 patent drawing
  • US10879876B2 patent drawing
  • US10879876B2 patent drawing

AI summary

Systems and methods are provided for channelizing. A first stage can provide a WOLA filter bank that can apply a single multiplier resource to perform window weighting for multiple WOLA filter banks. The first stage can remove mixer-based post FFT adjustment and provide equal functionality with a particular modification of tuning mixers at inputs of second stage FIR paths. The first stage can include a variable decimation, using a particular implementation of variable sample block size.