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Linear Predictive Coding - this page is a stub

Linear Predictive Coding (LPC), also known as LPC-10, FIPS 137 and FED-STD-1015, is a speech encoding standard, or vocoder, used in (secure) telephony. It is basically a method for digitizing speech by analyzing and storing specific characteristics of it, such as pitch and voiced/voiceless sounds, in such a way that an intelligible signal can be reconstructed later. The standard, finished on 28 November 1984, was developed by the US Department of Defense (DoD) and is based on the earlier STANAG 4198 standard, promulgated by NATO on 13 February 1984 [1].

LPC was used with early voice encryption equipment, such as STU-I, STU-II, VINSON KY-57 and Philips Spendex 40, and allows speech compression at low bitrates — typically between 800 and 2400 baud. LPC-10e was a US Government standard that was even used on STU-III terminals when running at 2400 baud. As it is an open standard, it was used by many manufacturers.

LPC-10 on this website
Secure Telehone Unit STU-I (KY-70)
Secure Telehone Unit (ITT, Northern Telecom)
Motorola STU-II/B SECTEL (NATO-version)
Secure Telehone Unit (Motorola, AT&T, RCA, etc.)
Wide-band Voice and Data Encryption Unit
Narrow-band Voice and Data Terminal
Philips Spendex-10, Narrow-band Voice and Data Terminal
Philips Spendex-40 secure telephone for voice, fax and computer
Philips PNVX secure crypto telephone
Telesecurity Timmann, TST-7698 Digital voice encryptor for HF/VHF/UHF radio
Harris RF-5811 secure voice and data unit
Siemens Crypset 100 crypto phone
Elcrovox 1-4D narrow band voice and data terminal (STU-II compatible)
TCE-500, secrure crypto telephone
CVAS III Secure Telephone
Telsy TX-1020C narrow-band radio voice scrambler and encryptor
Advanced INFOSEC Module
Embedded COMSEC module
BID/470 (BRAHMS) High-end portable telephone encryptor
  • Linear Predictive Coding
  • LPC
  • LPC-10
  • FIPS 137
  • FED-STD-1015
  • STANAG 4198
  1. Bishnu S. Atal, The History of Linear Prediction
    IEEE Signal Processing Magazine, March 2006. pp. 154-157, 161.

  2. Robert M. Gray, Linear Predictive Coding and the Internet Protocol
    Stanford University, USA. 2010. ISBN 978-1-60198-348-0.
  1. Wikipedia, FIPS 137
    Retrieved April 2021.

  2. Wikipedia, Linear predictive coding
    Retrieved 24 march 2024.

  3. Wikipedia, Linear prediction
    Retrieved 24 march 2024.
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Crypto Museum. Created: Saturday 03 April 2021. Last changed: Tuesday, 23 April 2024 - 14:33 CET.
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