Abstract:
The present invention discloses an underwater communication method using iterative codes. The underwater communication method according to one side of the present invention includes the steps of: encoding an original signal by a turbo code; comprising a packet by inserting start point display information, a silence section, synchronous information, a PN code, and information for correcting phase distortion into a preamble of the packet; and transmitting a signal to load the packet.
Abstract:
When selecting a backup cluster head, the present invention enables a node with best energy efficiency to be selected as the backup cluster head by considering three factors, which are the proximity to a cluster head, the amount of remaining energy, and the proximity to the center of a cluster. Therefore, the present invention enables a more optimal node to be selected when selecting a backup cluster head in a clustered vessel sensor network, thereby maximizing the lifespan of the vessel sensor network and enabling the vessel sensor network to be operated longer. [Reference numerals] (AA) Input value for selecting a backup cluster head;(BB) Output value of the selecting result of the backup cluster head;(CC) Fuzzification module;(DD) Deduction engine;(EE) Defuzzification module;(FF) Fuzzy rule for selecting a head;(GG) Selection possibility fuzzy group
Abstract:
PURPOSE: An Alamouti STBC applying method for enhancing performance of an offshore wind power radio communication control system is provided to apply a MIMO Alamouti STBC(Space-Time Block Coding) to a radio communication based control system, thereby improving transmission quality and reliability of the control system. CONSTITUTION: An Alamouti STBC applying method comprises the steps of: building multiple antennas using the overlay network technology; applying MIMO Alamouti STBC for optimal communication of the multiple antennas. When a control system operates normally, the control system processes valid data by interworking an up line with nets of odd numbers and a down line with nets of even numbers. When failing in forming a wireless link of the up line to a radio device in the front car of a train or detecting an error, the control system reads data of the radio device in the tail car for processing the data as valid data.
Abstract:
PURPOSE: A variable optical microwave notch filter is provided to extract a plurality of signal factors by a single element by a variable method and extract the signal factor in an optical base, thereby providing a method capable of extracting even when the frequency of a carrier is high, when using a plurality of signal carriers in order to receive a plurality of sensors. CONSTITUTION: A variable optical microwave notch filter has a property of obtaining a stable filtering characteristic regardless of the time delay of the reflective optical amplifier which is an incoherent source, and the length of the optical source coherence. The optical source becomes locked by auto-injection by a cavity which is generated between an RSOA(Reflective Optical Amplifier) and an FBG(Fiber optical Bragg Grating), and an oscillation wavelength of the RSOA, which is locked by auto-injection, is decided by a peak wavelength of the FBG.