Underwater acoustic receiver employing direct-sequence spreadspectrum and spatial diversity combining for shallow-water multiaccessnetworking

This paper proposes an underwater adaptive-array receiver structure that utilizes direct-sequence code division multiple access and spatial diversity combining in order to achieve reliable low-data rate multiuser communication in an asynchronous shallow-water network. The performance of the proposed receiver architecture has been verified by means of offline processing of data acquired during sea trials in the summer of 1999 in the North Sea. Results show that this computationally efficient structure is near-far resistant and provides successful multiuser operation in the shallow-water channel