Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Method for automatic synchronizing of audio-frequency watermark

An audio watermarking and self-synchronization technology, which is applied to the shaping network and baseband system components in the transmitter/receiver, can solve the problems of large interference, inapplicability, lack of robust and effective methods, etc., and achieves enhanced robustness. Robustness, the effect of improving the division accuracy

Active Publication Date: 2006-10-18
BEIJING KEXIN TECH +1
View PDF0 Cites 11 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For narrowband audio signals, due to some of its own characteristics, existing technologies are often not applicable
Such as short-wave audio broadcasting signal, which is characterized by narrow bandwidth, usually only 4kHz, and because it is sky-wave transmission, the interference is relatively large, and it is accompanied by interference fading, Doppler frequency shift, multipath effect, and same-frequency adjacent Frequency interference and other issues, so a more robust algorithm is needed
At the same time, the existing technology also lacks robust and effective methods for the research of data synchronization and frame synchronization.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for automatic synchronizing of audio-frequency watermark
  • Method for automatic synchronizing of audio-frequency watermark
  • Method for automatic synchronizing of audio-frequency watermark

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] The self-synchronized audio watermark method provided by the invention includes a watermark embedding method and a watermark extraction method. The algorithm of the watermark embedding method is as follows: figure 1 shown, including the following steps:

[0035] Step 101, perform RS coding on the watermark information.

[0036] In step 102, two different spreading code sequences (PN sequences) are generated and assigned to the watermark information and the synchronization information respectively, called the watermark information PN sequence and the synchronization PN sequence.

[0037] Step 103, performing time-frequency transformation on the input audio signal. That is, first add a Hanning window frame to the audio signal, and then perform FFT with a sliding step of 1 / 4 of the frame length to obtain the spectrum X(n) of the original carrier (audio signal).

[0038] Step 104, according to the input audio signal, calculate the parameter α through the masking model. ...

Embodiment 2

[0069] This embodiment is basically the same as Embodiment 1, except that another synchronization method is adopted.

[0070] In this example, refer to figure 1 , the steps 101, 103, 104, 106 of the watermark embedding method are completely consistent with those in Embodiment 1. refer to figure 2 , step 203 of the watermark extraction method is also completely consistent with Embodiment 1. The steps different from those in Example 1 are described below.

[0071] Watermark embedding method:

[0072] In step 102, a spreading code sequence (PN sequence) is generated for use when embedding watermark information and synchronization marks.

[0073] In step 105, the watermark information and the synchronization information are respectively embedded in different time periods by adopting the method of spreading sequence embedding. The embedding method is to convert X(n) into Y(n) according to formula (1), which is the same as that in Example 1. The difference is that in this emb...

Embodiment 3

[0081] This embodiment is improved on the basis of embodiment 1 (or embodiment 2).

[0082] In order to be able to adapt to some particularly bad situations in shortwave transmission (such as co-channel interference, that is, two or more transmitting stations use the same frequency to transmit different program content), the system can still receive mixed program signals Different watermark information is extracted from the watermark, and this embodiment uses a method including redundant embedding, data reorganization and data credibility measurement.

[0083] 1. Redundant embedding

[0084]In order to further improve the robustness of the watermark information, so that it can still obtain satisfactory results in the same frequency environment, redundant embedding is performed on the watermark data. The specific embedding method is as follows: For a set of watermark information, three spread spectrum sequences are used (same or different) for modulation, assuming that three s...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

An audio watermarking method of self-synchronization includes converting synchronous information and watermark information being RS coded to be two-way code base band signal then embedding synchronous and watermark information in audio signal frequency spectrum in sequence by means of spread spectrum sequence embedding when watermark is embedded, finalizing frame and data synchronization by picking up synchronous information with manner of moving correlation in communication then carrying out correlation detection on frequency spectrum of received signal for picking up watermark information when watermark is picked up.

Description

technical field [0001] The invention relates to digital watermark technology, in particular to a self-synchronizing audio watermark method suitable for short-wave narrowband channels. Background technique [0002] Digital watermarking is a research hotspot in multimedia information processing in recent years, and the research on audio watermarking has its own characteristics. The bandwidth of the sound signal is narrower, it is more convenient to transmit than the image and video signal, and the form is also more diverse. Such as telephone, audio broadcasting, and video audio, etc. are common in daily life, and its coverage is very extensive. [0003] So far, audio watermarking research has produced a variety of methods, which can be divided into two categories: time-domain algorithms and transform-domain algorithms. Most of the algorithm research objects in the prior art are wideband audio signals, and the general sampling rate is 32k or 44.1k. For narrowband audio signa...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): H04L25/03
Inventor 雷赟刘建颜永红
Owner BEIJING KEXIN TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com