Coded-GFDM for Reliable Communication in Underwater Acoustic Channels

Abstract

The performance of the coded generalized frequency division multiplexing (GFDM) transceiver has been evaluated in a shallow underwater acoustic channel (UAC). Acoustic transmission is the scheme of choice for communication in UAC since radio waves suffer from absorption and light waves scatter. Although orthogonal frequency division multiplexing (OFDM) has found its ground for multicarrier acoustic underwater communication, it suffers from high peak to average power ratio (PAPR) and out of band (OOB) emissions. We propose a coded-GFDM based multicarrier system since GFDM has a higher spectral efficiency compared to a traditional OFDM system. In doing so, we assess two block codes, namely Bose, Chaudari, and Hocquenghem (BCH) codes, Reed-Solomon (RS) codes, and several convolutional codes. We present the error performances of these codes when used with GFDM. Furthermore, we evaluate the performance of the proposed system using two equalizers: Matched Filter (MF) and Zero-Forcing (ZF). Simulation results show that among the various block coding schemes that we tested, BCH (31,6) and RS (15,3) give the best error performance. Among the convolutional codes that we tested, rate 1/4 convolutional codes give the best performance. However, the performance of BCH and RS codes is much better than the convolutional codes. Moreover, the performance of the ZF equalizer is marginally better than the MF equalizer. In conclusion, using the channel coding schemes with GFDM improves error performance manifolds thereby increasing the reliability of the GFDM system despite slightly higher complexity.

A Survey on Physical Layer Techniques and Challenges in Underwater Communication Systems

“…In UWAC, ISI is a major issue due to multipath propagation and fading. GFDM reduces the impact of ISI by using a pulse-shaping filter that provides good spectral containment and reduces ICI [99,100]. In conclusion, GFDM is a promising modulation technique for UWAC that provides improved performance in terms of spectral efficiency, robustness in synchronization errors, and mitigation of ISI.…”

MIMO Based GFDM with Channel Coding and Adaptive Decision Feedback Equalizer in Underwater Wireless Optical communication

“…Compared to single antenna wireless link, MIMO systems will provide specific important features like gain and improved channel capacity. For the next generation communication networks, Generalized Frequency Division Multiplexing (GFDM) [23] is the best techniques which overcome the drawback of existing OFDM system interms of higher spectral efficiency, flexibility and less OOB emissions. The primary purpose of this research is to examine how well Coded MIMO GFDM performs in UWOC systems, where data signals are sent by M transmitters and retrieved by N apertures.…”

Video Error-Resilience Encoding and Decoding Based on Wyner-Ziv Framework for Underwater Transmission

“…Using the visual perception in deep-sea environments, a variety of video applications can be transmitted through underwater acoustic channels, including seabed exploration, disaster prevention, mine reconnaissance, and environmental monitoring [1][2][3][4]. To fulfill the transmission needs for underwater video data, coding and transmission techniques have been proposed over underwater acoustic networks [5][6][7][8][9]. However, due to the characteristics of acoustic signals, an underwater acoustic communication system typically has three defects: narrow bandwidth, long-distance propagation delay, and errorprone transmission.…”