Author : Janki Patel 1
Date of Publication :24th January 2018
Abstract: The narrowband frequency range from about 300 Hz to 3.4 kHz. So, the audio quality of telephone network is restricted. Bandwidth extension(BWE) is used to extend narrowband(NB) frequency range to wideband(WB) frequency range which is 50 Hz to 7 kHz and wideband frequency range to super wideband(SWB) frequency range which is 50 Hz to 14 kHz. This bandwidth extension can be realized with or without side information. The Bandwidth extension is performed by adding missing frequencies artificially at the receiver using information contained in narrowband signal or either using some low bit rate side information. The basic principles of bandwidth extension address by this review paper and discuss different methods of bandwidth extension from narrowband to wideband and narrowband to super wideband.
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