Title :
An adaptive soft output GMSK demodulator over MUOS narrowband flat scintillation channels
Author :
Wu, Jie ; Seyedi, Alireza ; Saulnier, Gary J.
Author_Institution :
Electr., Comput. & Syst. Eng. Dept., Rensselaer Polytech. Inst., Troy, NY, USA
Abstract :
The signal scintillation effects at UHF represent a significant design challenge for the future military mobile user objective system (MUOS) satellite communications. An adaptive soft output demodulator for GMSK signaling with very small value is investigated in MUOS narrowband applications. Without any performance loss, significant complexity reduction is achieved by using differential precoding, the Laurent (1986) signal representation and sampling the received symbols at the end of the symbol duration. The performance of the GMSK demodulator over six typical MUOS flat scintillation channels, particularly over the worst-case scintillation channel among them, are studied through simulations in both uncoded and convolutional coded systems.
Keywords :
UHF radio propagation; channel estimation; convolutional codes; demodulators; least mean squares methods; minimum shift keying; mobile satellite communication; signal representation; signal sampling; telecommunication signalling; GMSK signaling; MUOS narrowband flat scintillation channels; MUOS satellite communications; UHF; adaptive soft output GMSK demodulator; convolutional coded systems; differential precoding; military mobile user objective system; nonlinear LMS channel estimator; signal representation; signal sampling; signal scintillation effects; simulations; symbol duration; uncoded systems; Convolution; Convolutional codes; Demodulation; Military communication; Narrowband; Performance loss; Sampling methods; Satellite communication; Signal design; Signal representations;
Conference_Titel :
MILCOM 2002. Proceedings
Print_ISBN :
0-7803-7625-0
DOI :
10.1109/MILCOM.2002.1180464
