Open AccessChirp spread spectrum of orthogonal frequency division multiplexing underwater acoustic communication system based on multi-path diversity receive
Author(s) -
Yilin Wang,
Ma Shi-Long,
Guolong Liang,
Fenghuang Zhan
Publication year - 2014
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.63.044302
Subject(s) - orthogonal frequency division multiplexing , chirp spread spectrum , fading , chirp , underwater acoustic communication , computer science , electronic engineering , diversity scheme , bandwidth (computing) , frequency domain , telecommunications , channel (broadcasting) , underwater , acoustics , spread spectrum , physics , engineering , direct sequence spread spectrum , optics , geology , laser , oceanography , computer vision
Aiming at the problem of traditional orthogonal frequency division multiplexing (OFDM) communication system performance degradation when the channel is subjected to complex multi-path and frequency-selective deeply fading, a chirp spread spectrum (CSS) of OFDM underwater acoustic communication system called CSS-OFDM is proposed in this paper. The CSS-OFDM system spreads the spectrum of traditional OFDM signals, whose sub-carriers are modulated into the same chirp rate, different center frequency orthogonal chirp signals with overlapped bandwidth. Dispreading after underwater acoustic coherent multi-path channel, at the receiving end, the multi-path signals will be expanded from each other in the frequency domain. Applying virtual time reversal mirror technology, the energies of the multi-path signals are focused to complete the multi-path channel diversity receiving. The system performance is improved not only by suppressing the frequency selective fading, but also taking full advantage of multi-path energy of the channel. The effectiveness and reliability of this system are verified through a number of simulations and lake trials.