Wireless Packet Detection via Interference Characteristic Sequences

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Solution Overview

Problem

Current packet detection methods for wireless signals, particularly in IEEE 802.11 protocols, suffer from low detection accuracy due to adjacent channel interference, leading to packet loss, power wastage, and abnormal system functions.

Innovation Solution

A packet detecting method and system that generates a local characteristic sequence and interference characteristic sequences based on signal sampling frequency and working frequency differences, performing cross-correlation operations to accurately determine if a packet is transmitted through a target channel by analyzing first and second cross-correlation results.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a cross-correlation operation between the received signal and a deterministic local characteristic sequence is performed to determine packet format, then packet detection can be performed, but detection accuracy is low and misjudgment occurs due to adjacent channel interference

Engineering Contradiction:

Improvedetection accuracyVSAvoidpacket loss and misjudgment

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent segments the detection process into two distinct stages: first detecting packet format using a local characteristic sequence, then detecting center frequency using an interference characteristic sequence. This segmentation allows each detection stage to focus on specific parameters, improving overall detection accuracy and reducing misjudgment caused by adjacent channel interference.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces an interference characteristic sequence as an intermediary element that specifically targets adjacent channel interference. By correlating the received signal with this interference characteristic sequence, the system can identify and eliminate the influence of adjacent channel signals, thereby improving the reliability of packet detection.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Loss of energy

If the receiver processes packets from adjacent channels due to frequency spectrum aliasing, then additional information is received, but power is wasted and erroneous information causes abnormal system functions

Engineering Contradiction:

Improvepower wastageVSAvoidadjacent channel interference

Core Design Contradiction:

Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The patent performs preliminary detection of the center frequency before fully processing the packet. By detecting the center frequency early in the reception process, the system can identify whether the signal comes from the target channel or an adjacent channel, allowing it to discard adjacent channel packets before substantial processing occurs, thus saving power and preventing erroneous information from affecting system functions.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses the results of cross-correlation operations with interference characteristic sequences as feedback to determine whether to continue processing a received signal. If the feedback indicates the signal is from an adjacent channel, the system stops further processing, thereby avoiding power wastage and preventing harmful effects from adjacent channel interference.

Inventive Principle:

Principle #23Feedback

3Measurement precision

If frequency spectrum lobes of adjacent channels are aliased due to 5 MHz frequency gap, then channel partitioning is achieved, but reception time points are shifted and packet loss occurs

Engineering Contradiction:

Improvereception time accuracyVSAvoidfrequency spectrum management

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent changes the detection parameter from only packet format recognition to include both packet format and center frequency detection. By detecting the center frequency parameter, the system can distinguish between signals from different channels even when frequency spectrum lobes are aliased, thereby maintaining reception time accuracy and preventing packet loss despite the complexity of frequency spectrum management.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11350296B2Packet detecting method of a wireless signal and packet detecting system of the wireless signal capable of identifying adjacent channel interference

Publication Date: 2022.05.31 REALTEK SEMICON CORP

AI summary

A packet detecting method includes receiving the wireless signal, generating a local characteristic sequence, acquiring a first cross-correlation result between the wireless signal and the local characteristic sequence, determining if a packet format of the wireless signal is a target packet format according to the first correlation result, generating at least one interference characteristic sequence according to the local characteristic sequence, a signal sampling frequency, and at least one working frequency difference, acquiring a second cross-correlation result between the wireless signal and the at least one interference characteristic sequence, and detecting a center frequency of the wireless signal for determining if a packet of the wireless signal is transmitted through a target channel according to the first correlation result and the second correlation result. The at least one interference characteristic sequence corresponds to at least one interference frequency.