翻訳と辞書
Words near each other
・ Vedanta University
・ Vedantam
・ Vedantam Raghavaiah
・ Vedantam Ramalinga Sastry
・ Vedantasara (of Sadananda)
・ Vedanth Bharadwaj
・ Vedanthangal Bird Sanctuary
・ Vedantu
・ Vedanā
・ Vedapatti
・ Vedaprofen
・ Vector space model
・ Vector spaces without fields
・ Vector spherical harmonics
・ Vector srv8
Vector sum excited linear prediction
・ Vector synthesis
・ Vector tiles
・ Vector training
・ Vector Unit
・ Vector W2
・ Vector W8
・ Vector WX-3
・ Vector WX-8
・ Vector-06C
・ Vector-based graphical user interface
・ Vector-field consistency
・ Vector-valued differential form
・ Vector-valued function
・ VectorBase


Dictionary Lists
翻訳と辞書 辞書検索 [ 開発暫定版 ]
スポンサード リンク

Vector sum excited linear prediction : ウィキペディア英語版
Vector sum excited linear prediction
Vector sum excited linear prediction (VSELP) is a speech coding method used in several cellular standards. The VSELP algorithm is an analysis-by-synthesis coding technique and belongs to the class of speech coding algorithms known as CELP (Code Excited Linear Prediction).〔ETSI, (EN 300 969 - Half rate speech transcoding (GSM 06.20 version 8.0.1 Release 1999) ), Retrieved on 2009-07-11〕
Variations of this codec have been used in several 2G cellular telephony standards, including IS-54, IS-136 (D-AMPS), GSM (Half Rate speech) and iDEN. It was also used in the first version of RealAudio for audio over the Internet. The IS-54 VSELP standard was published by the Telecommunications Industry Association in 1989.
D-AMPS (IS-54 and IS-136) VSELP specifies an encoding of each 20 ms of speech into 159-bit frames, thus achieving a raw data rate of 7.95 kbit/s. In an actual TDMA cell phone, the vocoder output is packaged with error correction and signaling information, resulting in an over-the-air data rate of 16.2 kbit/s. For internet audio, each 159-bit frame is stored in 20 bytes, leaving 1 bit unused. The resulting file thus has a data rate of exactly 8 kbit/s.
GSM half-rate VSELP (GSM 06.20) uses 20 ms frames with 112 bits per frame, giving a raw data rate of 5.6 kbit/s. The iDEN VSELP coder has three modes:
* 30 ms frames at 126 bits per frame with a raw data rate of 4.2 kbit/s,
* 22.5 ms frames at 99 bits per frame with a raw data rate of 4.4 kbit/s and
* 22.5 ms frames at 180 bits per frame with a raw data rate of 8.0 kbit/s.
A major drawback of VSELP is its limited ability to encode non-speech sounds, so that it performs poorly when encoding speech in the presence of background noise. For this reason, use of VSELP has been gradually phased out in favor of newer codecs.
VSELP is also the encoding method used in some early Motorola Type II trunking systems. It was phased out in favor of the newer IMBE method.
== External links ==

* (Telecommunications Industry Association web site )

抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)
ウィキペディアで「Vector sum excited linear prediction」の詳細全文を読む



スポンサード リンク
翻訳と辞書 : 翻訳のためのインターネットリソース

Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.