Hardware Implementation of Symbol Synchronization for Underwater FSK

Symbol synchronization is a critical component in the design of an underwater acoustic modem. Without accurate symbol synchronization, higher bit error rates incur thus reducing the reliability and quality of service of the wireless network. This paper provides a practical description of the design choices and hardware implementation details required to build a compact and efficient symbol synchronizer suitable for a short-range, low-power underwater FSK acoustic modem. Experimental results show the design meets the timing requirements of the underwater modem and provides accurate synchronization while consuming only 0.240 W power in a Spartan3 xc3s2000 FPGA.