Research On Macrodiversity Strategy For Marine Wireless Sensor Networks

Marine wireless sensor networks generally consist of considerable sensor nodes with wireless communication capability and data processing capability floating on the sea.It has a broad application in ocean observation and detection due to its low cost,easy deployment,and large-scale networking.However the transmission between the marine wireless sensor network nodes is very unreliable due to the harsh weather environment and complex electromagnetic characteristics on the sea.Based on this,this paper proposes a macrodiversity system architecture,and designs a highly reliable macrodiversity reception scheme for marine wireless sensor networks to improve the reliability of transmission.Specific work includes:Firstly,the software and hardware platform of macrodiversity reception system for marine wireless sensor network is established.This system is based on the wireless data transmission module CC1101 and ARM processor,and adopts a two-level diversity receiving scheme.The diversity reception system with four RF antennas is used as the remote antenna unit of the macrodiversity reception system to achieve reliable data transmission in the system.Considering the limited computing power of the central processing node,a cascaded diversity combining scheme was designed.By completing the diversity combining on each distributed receiving node and sending the combined information sequence to the central processing node.The computing load of system can be balanced to each distributed receiving node,which effectively reduces the operation load of the central processing node.Furthermore,we conduct tests in the land environment and the marine environment based on the established hardware experiment platform of the marine wireless sensor networks macrodiversity reception system,respectively.During the test,the performance of the macrodiversity reception system with different diversity weights is analyzed first.By counting the packet error rate and frame error rate of the number of the single-antenna receiving system,the four-antenna receiving system,and the eight-antenna receiving system at each position,the diversity reception performance under different diversity weights is compared.Then,in order to further analyze the performance of the macrodiversity reception system proposed in this paper,multiple groups of tests were performed at different positions within a certain distance range,and the performance of the macrodiversity reception system and the centralized multi-antenna reception system were compared.The experimental results show that the macrodiversity receiving system proposed in this paper can effectively improve the transmission reliability of the system within a certain range.When the number of receiving antennas are the same,the macrodiversity receiving system also has a higher transmission gain than the centralized multi-antenna system.