Water tank experiment on forward link underwater code division multiple access scheme

Code division multiple access (CDMA) is a promising medium access control (MAC) protocol for underwater acoustic sensor networks because of its robustness against frequency selective fading, and high frequency reuse efficiency. In this study, we design the forward link CDMA transceiver to operate in underwater acoustic channel environments, and we evaluate the feasibility using a water tank experiment. Users´ data are spread and orthogonally multiplexed using a Walsh code. Subsequently, a pseudorandom noise code acquisition process is added for phase error correction in the receiver.