Error protection for tactical voice modems

Author

Chan, C. Chiu

Author_Institution

ITT Aerosp./Commun. Div., Nutley, NJ, USA

fYear

1990

fDate

24-26 Apr 1990

Firstpage

481

Lastpage

498

Abstract

The coding techniques included convolutional codes and Reed-Solomon block codes. The speech input to the modem was compressed by using a 1200 bps low rate voice (LRV) algorithm. The modem operated on a high frequency (HF) fading channel using M-ary phase shift keying (PSK) modulation. The coding techniques were treated independently from the LRV algorithm. The code rate was varied to determine the coding gains obtainable in a fading channel. The value of M was also varied in conjunction with the code rate such that the transmission bandwidth remained fixed. Using 4-ary PSK, an optimal code rate of 1/2 for convolutional codes was found such that the Eb/No was minimized. Applying the optimal code rate, an optimal allocation of bits could be defined between the voice and error protection algorithms to make best use of the channel capacity

Keywords

error correction codes; military equipment; modems; phase shift keying; voice equipment; 1200 bit/s; 4-ary PSK; HF fading channel; LRV algorithm; M-ary phase shift keying; Reed-Solomon block codes; coding gains; convolutional codes; error protection; low rate voice algorithm; optimal bit allocation; optimal code rate; tactical voice modems; Block codes; Convolutional codes; Fading; Frequency shift keying; Hafnium; Modems; Phase shift keying; Protection; Reed-Solomon codes; Speech;

fLanguage

English

Publisher

ieee

Conference_Titel

Tactical Communications Conference, 1990. Vol.1. Tactical Communications. Challenges of the 1990's, Proceedings of the

Conference_Location

Fort Wayne, IN

Type

conf

DOI

10.1109/TCC.1990.177746

Filename

177746