SOFD Cyclic Prefix Autocorrelation Synchronization

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Start of Frame Delimiters (SOFD) in packet communications are prone to errors due to their short bit patterns and auto-correlation properties, which can lead to synchronization ambiguities and increased power consumption in receivers.

Innovation Solution

The method involves creating a SOFD with a cyclic prefix and/or postfix, using spreading codes like Barker or Gold Sequences, to minimize synchronization ambiguities and ensure ideal correlation behavior, thereby reducing errors and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a short bit pattern is used for SOFD, then the packet structure remains simple and transmission overhead is low, but synchronization ambiguities increase and error susceptibility rises

Engineering Contradiction:

Improvepacket structure complexityVSAvoidsynchronization accuracy

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The SOFD is segmented into multiple components: a cyclic prefix portion and a main SOFD portion. The cyclic prefix is created by copying and appending a portion of the main SOFD sequence to its beginning, creating a structured division that enables autocorrelation detection while maintaining overall sequence integrity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The cyclic prefix creates a periodic structure in the SOFD sequence. By appending a copy of the main SOFD portion to its beginning, the sequence exhibits periodic properties that enable reliable autocorrelation detection, allowing the receiver to identify synchronization points through the periodic pattern matching

Inventive Principle:

Principle #19Periodic action

2Loss of energy

If traditional SOFD patterns are used, then transmission overhead is minimized, but power consumption increases due to repeated receiver electronics activation

Engineering Contradiction:

Improvereceiver power consumptionVSAvoidpacket detection reliability

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The cyclic prefix serves as a preliminary indicator that prepares the receiver for the main SOFD. The autocorrelation property of the cyclic prefix allows the receiver to detect packet arrival and activate electronics in advance, rather than waiting for the main SOFD, thereby reducing unnecessary power consumption from repeated activation cycles

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The cyclic prefix acts as an intermediary element between the preamble and the main SOFD. It provides an initial detection signal that mediates the transition from idle state to active processing, enabling the receiver to prepare gradually and reduce power consumption while maintaining reliable packet detection

Inventive Principle:

Principle #24Intermediary (Mediator)

3Measurement precision

If SOFD auto-correlation properties are utilized for synchronization, then time alignment is achieved, but synchronization ambiguities may lead to incorrect packet identification

Engineering Contradiction:

Improvetime alignment accuracyVSAvoidsynchronization uniqueness

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

Different portions of the SOFD have different local qualities and functions. The cyclic prefix portion is optimized for autocorrelation detection with specific correlation properties, while the main SOFD portion contains the unique packet identification code. This local differentiation allows the cyclic prefix to provide precise time alignment through autocorrelation without causing synchronization ambiguities, as the main portion's unique code confirms correct packet identification

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS9300353B1Start of frame delimiter in a communication packet

Publication Date: 2016.03.29 NXP BV

AI summary

Various exemplary embodiments relate to a device for performing a method of communication transmission. The device may include a memory; a processor configured to: determine a spreading code with low sidelobe levels in its autocorrelation sequence to be used; create a Start of Frame Delimiter (SOFD) for a packet including the spreading code and a cyclic prefix, wherein the cyclic prefix is a portion of the spreading code; and transmit the packet with the SOFD.