WATERMARK - Simulation Toolbox to Validate the Test Signal in Underwater Wireless Communication

Abstract

Underwater Acoustic Communication (UAC) is a rapidly growing area in the field of research and engineering. It provide performance enhancement for various underwater applications such as climate monitoring, pollution control, gathering of scientific data, deep sea exploration, etc. However, it is much more challenging to communicate in water medium than in air medium. The reverberation effect in the UAC channel causes multipath effects results in larger delay spread. Moreover, the UAC channel undergoes rapid temporal and spatial variation and it poses a great challenge for high data rate communication. The various techniques that are used at radio frequencies do not work in the UAC channel. This is one of the foremost reasons for low data rate and short range communication. To deal with the highly dispersive and time varying characteristics of UAC channel, coherent single carrier modulation can be applied along with the decision feedback equalizer. As the symbol rate increases, the frequency selectivity of the channel leads to high BER. To overcome this, a multicarrier modulation scheme can be used. To achieve a reliable wireless communication in the air medium, Electromagnetic (EM) waves can be used. These waves have been used extensively for long-range communication. For water medium, propagation of EM waves are of not much use. Moreover, these waves can travel only few meters and attenuated more for long range. Another important issue in underwater communication is the validation of data. In this article, a real time simulation toolbox, WATERMARK tool is illustrated clearly to understand about the toolbox and how it can be used for the validation of data in the real time scenario. Three different modulation scheme was applied for the simulation purpose and its Bit Error Rate was compared.