VSELP meaning in General ?

General Miscellaneous in General . 2 years ago

  1.91K   0   0   0   0 tuteeHUB earn credit +10 pts

5 Star Rating 1 Rating
What is Vector Sum Excited Linear Prediction mean?

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).

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 and22.5 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.

reference

Posted on 26 Apr 2022, this text provides information on General related to Miscellaneous in General. Please note that while accuracy is prioritized, the data presented might not be entirely correct or up-to-date. This information is offered for general knowledge and informational purposes only, and should not be considered as a substitute for professional advice.

Take Quiz To Earn Credits!

Turn Your Knowledge into Earnings.

tuteehub_quiz

Tuteehub forum answer Answers

Post Answer

No matter what stage you're at in your education or career, TuteeHub will help you reach the next level that you're aiming for. Simply,Choose a subject/topic and get started in self-paced practice sessions to improve your knowledge and scores.