In a high-power underwater wireless optical communication (UWOC) system, the bandwidth limitations of high-power optical sources and high-sensitivity detectors and the multipath effect of seawater channels can cause intersymbol interference, which seriously affects the performance of the UWOC system. Based on the attenuation characteristics and time-domain broadening characteristics of underwater wireless optical signals, a dual-mode adaptive switching blind equalization algorithm is proposed; it combines the variable step size constant-to-mode fractional spaced equalizer (FSE) algorithm and the decision directed least-mean-square mode-FSE algorithm to improve the performance of long-distance UWOC systems. Simulations show that the proposed algorithm has antinoise performance under different seawater qualities. In particular, with a bit error rate performance of 10 − 4 in coastal seawater, the signal-to-noise ratio of the proposed algorithm is 5.2 dB lower than the traditional constant-to-mode decision directed least-mean-square algorithm and 9.2 dB lower than that when the algorithm is not equalized.
KEYWORDS: Signal to noise ratio, Signal attenuation, Signal detection, Telecommunications, Interference (communication), Receivers, Avalanche photodetectors, Eye, Wireless communications, Transceivers
In underwater wireless optical communications (UWOC), low signal-to-noise ratio (SNR) and baseline drift problems caused by the attenuation of seawater channels and limited bandwidth of the transceiver system deteriorate the quality of the received signal and result in a higher bit error rate (BER). The transmission characteristics of underwater optical communication systems are analyzed, and a scheme combining length-limited coding and improved energy detection is proposed to improve the detection performance under low SNR and baseline drift. Experiments show that the scheme can improve the performance of the intensity-modulated direct-detection nonreturn-to-zero UWOC system. The BER performance of 3 × 10 − 4 can be achieved at SNR = 5.14 dB, which lays the foundation for long-distance UWOC.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.