TY - GEN
T1 - On the capacity and system design of relay-aided underwater acoustic communications
AU - Cao, Rui
AU - Qu, Fengzhong
AU - Yang, Liuqing
PY - 2010
Y1 - 2010
N2 - In underwater acoustic communications (UAC), frequency-dependent signal attenuation, long propagation delay and doubly-selective fading channels render reliable communications a challenging problem, especially at long distances. To enhance reliability and to extend range, relay communications have been extensively studied in terrestrial environments. However, their application to UAC has not been thoroughly explored. In this paper, we analyze the capacity of relay-aided (RA-)UAC. The result shows a prominent capacity increase in RA-UAC systems, when compared with traditional direct-link UAC. In addition, effects of various system parameters on capacity are also evaluated. These parameters include source-to-destination distance, transmit power allocation and relay location. To realize the benefits of RA-UAC, special considerations are to be taken in practical RA-UAC system designs. To account for and to take advantage of the unique characteristics of UAC channels, we develop a practical asynchronous amplify-and-forward (AF) relay system for UAC. To collect the ample multipath energy and diversity enabled by this relaying protocol, we also employ the precoded orthogonal frequency division multiplexing (OFDM) as the basic physical layer module. Our system resolves both the time synchronization difficulty and frequency selectivity of UAC. Simulations and comparisons are presented to verify our analysis and design.
AB - In underwater acoustic communications (UAC), frequency-dependent signal attenuation, long propagation delay and doubly-selective fading channels render reliable communications a challenging problem, especially at long distances. To enhance reliability and to extend range, relay communications have been extensively studied in terrestrial environments. However, their application to UAC has not been thoroughly explored. In this paper, we analyze the capacity of relay-aided (RA-)UAC. The result shows a prominent capacity increase in RA-UAC systems, when compared with traditional direct-link UAC. In addition, effects of various system parameters on capacity are also evaluated. These parameters include source-to-destination distance, transmit power allocation and relay location. To realize the benefits of RA-UAC, special considerations are to be taken in practical RA-UAC system designs. To account for and to take advantage of the unique characteristics of UAC channels, we develop a practical asynchronous amplify-and-forward (AF) relay system for UAC. To collect the ample multipath energy and diversity enabled by this relaying protocol, we also employ the precoded orthogonal frequency division multiplexing (OFDM) as the basic physical layer module. Our system resolves both the time synchronization difficulty and frequency selectivity of UAC. Simulations and comparisons are presented to verify our analysis and design.
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U2 - 10.1109/WCNC.2010.5506306
DO - 10.1109/WCNC.2010.5506306
M3 - Conference contribution
AN - SCOPUS:77955018737
SN - 9781424463985
T3 - IEEE Wireless Communications and Networking Conference, WCNC
BT - 2010 IEEE Wireless Communications and Networking Conference, WCNC 2010 - Proceedings
T2 - IEEE Wireless Communications and Networking Conference 2010, WCNC 2010
Y2 - 18 April 2010 through 21 April 2010
ER -