Title :
Chirp FSK modem for high reliability communication in shallow water
Author :
LeBlanc, Lester R. ; Beaujean, Pierre-Philippe ; Singer, Matthew ; Oubli, Cecileb ; Strutt, Guenael T.
Author_Institution :
Dept. of Ocean Eng., Florida Atlantic Univ., Dania Beach, FL, USA
Abstract :
A high reliability shallow water acoustic modem has been developed for communication between AUVs and for general oceanographic use. The modem uses 56 narrowband chirp FM pulses, each centered at a unique frequency located in the range of 20 kHz to 30 kHz. Communication rates vary from 300 bps to 2400 bps, depending on the transmission mode. Packets of information are synchronized using two dedicated chirp pulses, followed by transmission format information. In the auto-baud mode, the modem uses information gathered from previous transmissions for adaptation of baud rate to the acoustic environment. At the lowest rate (300 bps), frequency hopping in combination with a one-of-eight mode of transmission is used to provide maximum SNR and immunity to multipath interference. Performance analysis is presented
Keywords :
chirp modulation; frequency hop communication; frequency modulation; frequency shift keying; modems; multipath channels; synchronisation; telecommunication network reliability; underwater acoustic communication; 20 to 30 kHz; 300 to 2400 bit/s; AUV; SNR; acoustic modem; auto-baud mode; baud rate; chirp FSK modem; communication rates; frequency hopping; high reliability communication; multipath interference; narrowband chirp FM pulses; one-of-eight mode; packet transmission; shallow water; synchronized information; transmission format information; transmission mode; Acoustic pulses; Chirp; Frequency shift keying; Frequency synchronization; Interference; Modems; Narrowband; Performance analysis; Spread spectrum communication; Underwater communication;
Conference_Titel :
OCEANS '99 MTS/IEEE. Riding the Crest into the 21st Century
Conference_Location :
Seattle, WA
Print_ISBN :
0-7803-5628-4
DOI :
10.1109/OCEANS.1999.799736
