Pseudo Circular Preamble for GFDM Synchronization

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Solution Overview

Problem

Current synchronization methods for Generalized Frequency Division Multiplexing (GFDM) systems lack efficiency and do not exploit the unique properties of GFDM, leading to challenges in detecting symbol timing offset and carrier frequency offset, which affects the system's ability to utilize vacant frequency bands effectively.

Innovation Solution

A pseudo circular preamble using a special data sequence in the cyclic prefix and cyclic suffix is introduced to enable precise detection of symbol timing offset and carrier frequency offset, allowing for efficient synchronization and ultra-low out-of-band radiation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional synchronization methods are used in GFDM systems, then the system can operate without specialized preamble structures, but the detection of symbol timing offset and carrier frequency offset becomes imprecise

Engineering Contradiction:
Improvedetection precision of symbol timing offset and carrier frequency offsetVSAvoidcomplexity of synchronization structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by inserting a specially designed pseudo-circular preamble at the beginning of each transmit block before the actual data transmission. This preamble contains predetermined known sequences that enable the receiver to perform synchronization operations in advance, accurately detecting symbol timing offset and carrier frequency offset before data reception begins, thus resolving the contradiction between measurement precision and device complexity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses the pseudo-circular preamble as an intermediary element between the transmitter and receiver. This preamble structure, containing specific known sequences, acts as a mediator that facilitates the synchronization process by providing reference signals that the receiver can correlate with to determine timing and frequency offsets, thereby improving detection precision without requiring complex synchronization algorithms.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If GFDM systems use uniform transmission parameters across sub-bands, then the system design becomes simpler, but the ability to exploit unique GFDM properties for efficient synchronization is reduced

Engineering Contradiction:
Improveability to exploit unique GFDM propertiesVSAvoidcomplexity of transmission parameter configuration
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by designing transmission parameters specifically for the preamble portion of the signal. The pseudo-circular preamble uses particular known sequences and structures that are optimized for synchronization purposes, while the main data portion can use different parameters. This localized optimization enables the system to exploit unique GFDM properties for efficient synchronization without requiring complex configuration across the entire transmission, thus resolving the contradiction between adaptability and device complexity.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2884709B1Gfdm radio transmission using a pseudo circular preamble
Publication Date: 2019.07.31 VODAFONE GMBH
  • EP2884709B1 patent drawingFigure 1a~1b
  • EP2884709B1 patent drawingFigure 2
  • EP2884709B1 patent drawingFigure 3a

AI summary

A radio transmission system based on a frequency divisional multiplexing method is described, comprising an improved method for estimating symbol timing offset and frequency timing offset. The receiver estimates the symbol timing offset based of a block of received symbols based on a cyclic prefix and suffix.