Frequency band expansion method and device

A frequency band expansion and high frequency band technology, applied in the field of frequency band expansion methods and devices, can solve problems such as linear prediction coefficient errors, large differences in output signal performance, and poor broadband signal quality and performance, and achieve good quality and performance. good quality effect

Active Publication Date: 2011-03-30
HUAWEI TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In the process of realizing the present invention, the inventor found that there are at least the following problems in the prior art: the codebook used in the prior art converts linear prediction coefficients into line spectrum frequency parameters, Mel cepstral coefficients and other representations In the domain, according to the relationship between low-frequency and high-frequency broadband signals, a codebook with high-frequency and low-frequency mapping relationship is trained. This codebook has a great relationship with the language used in the training process

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  • Frequency band expansion method and device

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Embodiment 1

[0029] An embodiment of the present invention provides a frequency band extension method, such as figure 1 As shown, the method includes:

[0030] 101. Obtain the type of broadband signal; the type of the broadband signal is generally classified according to the characteristics of the signal itself, such as pitch period, zero-crossing rate and correlation, etc., which may include voiced signal, unvoiced signal, etc.; different The sound signals emitted by language and language include signal characteristics such as pitch period, zero-crossing rate and correlation. Therefore, when classifying broadband signals, they are not limited by language and language but only according to the characteristics of the signal itself. Speech signals from different languages ​​and languages ​​can obtain broadband signals with better quality during the process of frequency band expansion, thereby improving the auditory quality of the human ear.

[0031] Among them, when extending the low-freque...

Embodiment 2

[0042] An embodiment of the present invention provides a frequency band extension method, such as image 3 As shown, the method includes:

[0043] 301. Obtain the type of the broadband signal.

[0044] Among them, when extending the low-frequency signal to a high-frequency signal, since the spectrum fine structure and spectrum envelope characteristics of different types of signals are not the same, in order to enable various types of low-frequency signals to more accurately predict the high-frequency band Spectrum fine structure and spectrum envelope, generally select low-band spectral coefficients and low-band spectral envelopes of different frequency bands according to the broadband signal type for prediction. However, it is generally impossible to directly predict the type of the above-mentioned broadband signal at the receiving end, and it can be obtained in two ways, which specifically include: first, when the encoding end does not transmit any other information except l...

Embodiment 3

[0090] An embodiment of the present invention provides a frequency band extension method, such as Figure 5 As shown, the method includes:

[0091] 501. Obtain the type of the broadband signal; wherein, the specific method for obtaining the type of the broadband signal is as described in step 301 in Embodiment 2, and details will not be described here.

[0092] 502. Predict a fine structure of a high-band spectrum according to the type of the wide-band signal and the low-band spectrum. In the embodiment of the present invention, the fine structure of the high-band spectrum is predicted by flattening the low-band spectrum in the time domain as an example, and the frequency band extension method is specifically described.

[0093] In the process of predicting the fine structure of the high-band spectrum according to the type of the wide-band signal and the low-band spectrum, step 5021 needs to be executed first.

[0094]5021. Perform linear prediction analysis on the low-frequ...

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Abstract

The embodiment of the invention discloses a frequency band expansion method and a frequency band expansion device, relates to the field of communication, realizes signals for different languages or language systems, and can acquire high-quality broadband signals. The method of the embodiment comprises: acquiring the type of a broadband signal; predicting the fine structure and envelope of a high-band spectrum according to the type of the broadband signal and a low band spectrum; weighting the fine structure and envelope of the high-band spectrum to obtain a high-band spectrum; combining a low-band spectrum and the high-band spectrum to into a broadband spectrum; and performing the frequency-time conversion of the broadband spectrum and obtaining a broadband signal.

Description

technical field [0001] The invention relates to the field of communication, in particular to a frequency band extension method and device. Background technique [0002] Due to limitations of transmission bandwidth and other conditions, voice signals in a traditional PSTN (Public Switched Telephone Network, Public Switched Telephone Network) network are all transmitted in a narrowband form. The narrowband signal greatly limits the quality of human hearing. [0003] In view of the above problems, the prior art provides a simple and effective method for obtaining wideband voice without switching the current narrowband network, which is blind frequency band extension technology. The current blind extension technology is basically processed in the time domain. The specific operations include: firstly perform linear prediction analysis on the narrowband signal to obtain the linear prediction coefficient and residual signal of the narrowband signal, and then convert the narrowband...

Claims

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Application Information

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IPC IPC(8): G10L21/02G10L21/038
Inventor 刘泽新陈龙吟苗磊齐峰岩胡晨吴文海郎玥张清
Owner HUAWEI TECH CO LTD
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