Symbol-Synchronous Continuous Fast Convolution for Flexible 5G Subbands

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Solution Overview

Problem

Existing 5G communication systems face challenges in achieving high spectral containment and flexibility in multiplexing multiple subbands due to the limitations of conventional CP-OFDM and continuous FC processing schemes, particularly when dealing with mixed numerologies and abrupt changes in bandwidth or center frequency.

Innovation Solution

Implementing a symbol-synchronous continuous fast-convolution-based processing scheme that dynamically adjusts the overlap between FC processing blocks, allowing for flexible configuration of filtering parameters to improve spectral containment and reduce memory and latency requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional CP-OFDM processing is used, then implementation is simple, but spectral containment is insufficient

Engineering Contradiction:
Improveimplementation simplicityVSAvoidspectral containment
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent segments the continuous signal processing into discrete Fast Convolution blocks operating in the frequency domain. Each block processes specific subbands with independent filtering, allowing precise spectral control while maintaining computational feasibility through modular implementation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces time-domain convolution operations with frequency-domain Fast Convolution processing. This substitution transforms the mechanical signal processing approach into a computationally efficient frequency-domain operation, achieving better spectral containment while reducing computational complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Object-generated harmful factors

If continuous FC processing is used, then spectral containment improves, but flexibility in multiplexing multiple subbands deteriorates

Engineering Contradiction:
Improvespectral containmentVSAvoidmultiplexing flexibility
Core Design Contradiction:
Object-generated harmful factorsVSAdaptability or versatility

Solution Approach 1:

The patent introduces dynamic configurability to the FC processing blocks, allowing runtime adjustment of filtering parameters, subband assignments, and numerology configurations. This dynamic adaptation enables flexible multiplexing of multiple subbands while preserving spectral containment benefits.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent enables independent configuration of filtering parameters for different subbands and numerologies. By allowing parameter changes across multiple dimensions (filter width, block size, sampling rates), the system achieves both spectral containment and multiplexing flexibility simultaneously.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If unified FC processing block length is used, then implementation is simplified, but performance deteriorates with abrupt bandwidth changes

Engineering Contradiction:
Improveprocessing block configurationVSAvoidperformance with bandwidth changes
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent makes the FC processing block length dynamic rather than fixed. Block lengths adapt to the specific subband and numerology being processed, allowing optimal performance for each configuration while maintaining implementation simplicity through standardized control mechanisms.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies different FC processing block lengths to different subbands and numerologies based on their specific requirements. Each local processing region is optimized for its particular characteristics, achieving high performance across diverse scenarios without requiring a completely complex unified system.

Inventive Principle:
Principle #3Local quality

4Productivity

If filtering parameters are adjusted for each subband, then multiplexing efficiency improves, but memory and latency requirements increase

Engineering Contradiction:
Improvemultiplexing efficiencyVSAvoidmemory and latency resources
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent designs the FC processing blocks with universal structures that can handle multiple subbands and numerologies. By using common processing frameworks and shared resources across different subband configurations, the system achieves high multiplexing efficiency without proportionally increasing memory and latency requirements.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4241427B1Symbol-synchronous continuous fast-convolution-based processing
Publication Date: 2025.08.06 NOKIA SOLUTIONS & NETWORKS OY
  • EP4241427B1 patent drawingFigure 1
  • EP4241427B1 patent drawingFigure 2~3A
  • EP4241427B1 patent drawingFigure 3B

AI summary

According to an aspect, there is provided an apparatus comprising for performing the following. The apparatus receives a stream of orthogonal frequency division multiplexing symbols and associated cyclic prefixes produced by at least one orthogonal frequency- division multiplexing modulator of a radio transmitter or transceiver. The apparatus divides said stream into a plurality of overlapping processing blocks of a first length. At least one of the plurality of overlapping processing blocks comprises a non-overlapping section having values corresponding to a segment of said stream. The dividing comprises adjusting a length of the non-overlapping section at least based on whether a cyclic prefix is comprised in said segment and, if this is true, on a length of said cyclic prefix. The apparatus filters the plurality of overlapping processing blocks using fast convolution processing and concatenates filtered processing blocks to form an output signal for transmission using the radio transmitter or transceiver.