Low probability of detection for underwater acoustic communication

The ability to avoid detection of a communication signal in the underwater acoustic channel is extremely important for underwater acoustic communication (UWAC) systems when used for military-related applications. Furthermore, low probability of detection (LPD) may reduce environmental impact of UWAC as communication signals can be transmitted at lower power. In this paper, we study the LPD capability of UWAC systems. We consider an interceptor employing energy detector and calculate the minimal signal-to-noise power ratio (SNPR) which satisfies its required performance. For the receiver, we calculate the minimal required SNPR to allow reliable detection and decoding of a data packet using spread-spectrum signaling. We then analyze the LPD capability of the system for different channel and communication parameters.