Design And Engineering Implementation Of Base-band System For Maritime Cognitive Wireless Transmitter

With the development of the maritime transportation industry,the number of ships is increasing,and the ship is changing in the direction of large-scale and high-speed.The maritime communication service is developing at a high speed,and the demand for spectrum in maritime communication is increasing,and the wireless spectrum is becoming scarcer as a limited natural resource.The construction of a maritime cognitive radio communication system is an effective solution.In the maritime cognitive radio system,the bandwidth is adaptively adjusted due to different detection standards,and the number of sub-carriers is adjustable.The basic sensing and spectrum shaping capabilities of Orthogonal Frequency Division Multiplexing(OFDM)technology,together with its flexibility and adaptability,make it the best transmission technology in maritime cognitive radio networks.And can dynamic spectrum accessing and spectrum sharing.The paper builds a maritime cognitive wireless transmitter base-band system based on OFDM technology.The paper divides the maritime cognitive radio transmitter base-band system into channel coding and base-band modulation.The top-down idea is used to divide the whole system into multiple functional sub-modules to design and implement.The channel coding part includes a Hamming coding module,a cyclic redundancy check module,a Turbo coding module,and a bit scrambling code module.Due to the different detection criteria in the maritime cognitive radio system and the adjustability of the number of sub-carriers,the base-band modulation in the transmitter base-band system employs OFDM modulation,which includes an offset 7r/4 QPSK modulation and an inverse fast Fourier transform module.The paper studies the engineering implementation of the maritime cognitive wireless transmitter base-band system.In engineering,it is divided into two aspects:MATLAB simulation based on implementation scheme and engineering implementation based on FPGA.In the aspect of simulation,the tool MATLAB R2014a is used to carry out a comprehensive system modeling of the overall architecture of the maritime cognitive wireless transmitter base-band system,and the system flow that can support the project implementation is constructed,and the corresponding simulation diagram is given.In terms of engineering implementation,the FPGA platform provided by Xilinx is used to complete the engineering simulation and the Zedboard development board developed by Xilinx was used to complete the project.This topic is part of the National Natural Science Fund Youth Fund project"Unauthorized Spectrum Sensing and Resource Allocation Algorithm Research for Maritime Cognitive Wireless Communication System(61501078)",which mainly studies the design and engineering implementation of the maritime cognitive wireless transmitter base-band system.