Filter-Bank Demultiplexing with Selective Clock Gating

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Solution Overview

Problem

Conventional Fourier transform circuits are unable to operate selectively on part of the system band, leading to increased power consumption during demultiplexing and multiplexing processes.

Innovation Solution

A demultiplexing and multiplexing device with a 3-stage configuration that uses frequency-conversion and low-pass filtering units to reduce the sampling rate and filter signals, allowing for selective processing and reducing power consumption by stopping clock supply to unnecessary circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a Fourier transform circuit performs processing for the entire system band, then the processing coverage is complete, but power consumption increases

Engineering Contradiction:
Improvepower consumptionVSAvoidselective processing capability
Core Design Contradiction:
Use of energy by moving objectVSAdaptability or versatility

Solution Approach 1:

The system band is divided into multiple sub-bands, and the Fourier transform circuit is segmented into multiple processing units, each responsible for a specific sub-band. This allows selective activation of only those processing units needed for the current operation, reducing overall power consumption while maintaining the ability to process the entire system band when necessary.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The circuit configuration is made dynamic by enabling selective activation of different processing units based on the actual processing requirements. When only part of the system band needs processing, only the corresponding processing units are activated, allowing the system to adapt its power consumption to the actual workload.

Inventive Principle:
Principle #15Dynamics

2Use of energy by stationary object

If the entire Fourier transform circuit operates, then all signal bands can be processed, but unnecessary circuits consume power

Engineering Contradiction:
Improvecircuit power consumptionVSAvoidsignal processing capability
Core Design Contradiction:
Use of energy by stationary objectVSProductivity

Solution Approach 1:

The necessary signal processing capability is extracted and isolated into specific processing units that can be independently activated. By taking out only the required processing functions from the entire circuit, the system can maintain full signal processing capability when needed while consuming less power during partial-band operations.

Inventive Principle:
Principle #2Taking out (Extraction)

3Use of energy by moving object

If clock supply is continuous to all circuits, then processing is uninterrupted, but power consumption increases

Engineering Contradiction:
Improvepower consumptionVSAvoidprocessing continuity
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

Clock supply is implemented as a periodic action rather than continuous supply. Clock signals are provided only to the processing units that are currently active and processing signals, creating a periodic activation pattern that reduces power consumption while ensuring that processing is uninterrupted for the active units.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP2509223B1Demultiplexing device, multiplexing device and relay device
Publication Date: 2020.04.08 MITSUBISHI ELECTRIC CORP
  • EP2509223B1 patent drawingFigure 1
  • EP2509223B1 patent drawingFigure 2
  • EP2509223B1 patent drawingFigure 3

AI summary

To obtain a demultiplexing device that can reduce power consumption. The demultiplexing device includes frequency-conversion and reception low-pass-filter units 101 to 114 that perform a frequency converting process and a low-pass filtering process for causing a signal to pass through a desired band, perform downsampling to reduce a sampling rate to half of a data rate of an input signal, and output the signal, reception channel-filter units 121 to 128 that waveform-shape a signal with a desired frequency characteristic and output the waveform-shaped signal, a filter-bank control unit 13 that generates a clock control signal for supplying a clock to frequency-conversion and reception low-pass-filter units and reception channel-filter units corresponding to signal passage bands, based on channel information, and a reception-clock supply unit 14 that supplies a clock to frequency-conversion and reception low-pass-filter units and reception channel-filter units corresponding to signal passage bands, based on the clock control signal.