Title :
Error correction/masking for digital voice transmission over the land mobile satellite system
Author :
Bryden, Brian ; Séguin, Gérald E. ; Conan, Jean ; Bhargava, Vijay K. ; Brind´Amour, A.
Author_Institution :
Dept. of Commun., Commun. Res. Centre, Ottawa, Ont., Canada
fDate :
3/1/1989 12:00:00 AM
Abstract :
The development of a 2400-b/s speech digitizer which provides an acceptable level of intelligibility and quality over land mobile satellite channels is described. Performance tests over simulated channels in the UHF band (800 MHz) are presented. The voice digitizer is a linear prediction (LPC) vocoder which uses a channel error correction and concealment procedure tailored to error statistics for a minimum-shift keyed (MSK) downlink to a moving vehicle. The error-handling technique is based on perceptual criteria and utilizes the parametric nature of LPC representation of speech. A single-error-correcting, single-burst-detecting (28, 20) fire code is shown to be the best choice for the application. The intelligibility of the vocoder is measured and compared to the standard LPC-10 algorithm. The major remaining sources of speech quality degradation due to channel errors are determined and ranked
Keywords :
error correction; error correction codes; minimum shift keying; satellite relay systems; speech analysis and processing; telecommunication channels; vocoders; 2.4 kbit/s; 800 MHz; MSK downlink; UHF; channel error concealment; channel error correction; digital voice transmission; error correction codes; error statistics; error-handling technique; fire code; land mobile satellite system; linear prediction vocoder; moving vehicle; perceptual criteria; simulated channels; speech digitiser; speech quality degradation; Downlink; Error analysis; Error correction; Fires; Linear predictive coding; Satellites; Speech; Testing; Vehicles; Vocoders;
Journal_Title :
Communications, IEEE Transactions on
