Non-line-of-sight communication links over sea surface at 5.5GHz

This paper presents an experimental study of sea-to-land NLOS (non-line-of-sight) channel characterization at 5GHz band. The sea-to-land link is blocked by different large ships. This study is based on wideband channel measurements. The transmitter is installed on board a boat and the receiver is located at the top of the building on the shore. Different types of ships anchored off the east coast of Singapore are used as blockage to create the NLOS propagation scenario. Based on the structure and height of the blockage ships, they are classified into three types. Analysis of the measurement results associated with the three types of blockage ship is then discussed in terms of the “stand-off” distance. In order to verify the stand-off distance obtained from measurement results, 3-D ray tracing simulations are performed. The measured stand-off distance is found to agree with the simulated stand-off distance. This result is useful for military applications such as surveillance purposes.