南海无线电“白频谱”占用度研究

发布时间：2018-11-14 07:31

【摘要】：为了服务于南海上数千万的渔民和各国往来船只,政府正着手在南海上实现无线网络覆盖。无线网络的工作频段选择是实现海上无线网络覆盖工程的前提。海上无线传播环境与陆地上无线信号传播环境不同,海上基站建设困难、传输距离远、遮挡物少、湿度大、海水会反射和吸收电磁波、海水电导率、海洋表面风速等因素都与陆地无线网络覆盖不同,在传播距离足够远时,还要考虑地球的曲率半径对电磁波的绕射影响等。为了适应海上恶劣的无线电传播环境,需要寻找不易被海水吸收、穿透力强、传播距离远、信道容量大的频段来作为无线网络的工作频段。为了在匮乏的频谱资源中寻找南海无线网络的可用频段,了解南海区域在VHF/UHF频段的占用情况,现对该频段在南海部分海域及岛屿上的占用度进行了测量研究,分析了该频段的频谱占用度信息,实测数据表明,700MHz频段在所测量海域范围内随着远离海岸而明显降低,在距离约10km的地方广播电视信号就很弱了,甚至淹没在背景噪声中,由此可以推测,在距离更远的南海海域上,该频段的占用度几乎为零,因此,该频段在时间和地域上分布都是不均匀的,并且有大部分频段是空闲的。另一方面,由于广播电视发展较早,信息传输量大,因此采用了电磁频谱中的黄金频段,目前广电部门正在进行模拟电视向数字电视的转换,等完成整体转换后,广电将让出部分频谱用于无线宽带的发展,因此,可以对该频段进行复用来实施海洋无线网络的覆盖工程。
[Abstract]:To serve tens of millions of fishermen and ships across the South China Sea, the government is working on wireless coverage in the South China Sea. The selection of working frequency band of wireless network is the premise of the marine wireless network coverage project. The marine wireless transmission environment is different from the terrestrial wireless signal transmission environment, the base station at sea is difficult to build, the transmission distance is long, the occlusion is less, the humidity is high, the sea water will reflect and absorb the electromagnetic wave, the sea water conductivity, The wind speed of ocean surface is different from that of terrestrial wireless network. When the distance is long enough, the influence of the radius of curvature of the earth on the diffraction of electromagnetic wave should be considered. In order to adapt to the bad radio transmission environment at sea, it is necessary to find the frequency band which is difficult to be absorbed by sea water, strong penetration, long propagation distance and large channel capacity to work as the frequency band of wireless network. In order to find out the available frequency band of the South China Sea wireless network in the scarce spectrum resources and to understand the occupation of the South China Sea region in the VHF/UHF frequency band, the occupancy of the frequency band in some parts of the South China Sea and on the islands has been measured and studied. The spectrum occupancy information of the frequency band is analyzed. The measured data show that the 700MHz band decreases obviously with the distance from the coast in the sea area measured, and the radio and television signal is weak at a distance of about 10km, and even submerged in the background noise. It can be inferred that the occupation of the frequency band is almost zero in the farther South China Sea. Therefore, the frequency band is unevenly distributed in time and region, and most of the frequency band is idle. On the other hand, because of the earlier development of radio and television and the large amount of information transmission, the golden frequency band in the electromagnetic spectrum has been adopted. At present, the radio and television departments are currently carrying out the conversion from analog television to digital television, and so on, after the overall conversion, Radio and television will release part of the spectrum for the development of wireless broadband, so the frequency band can be multiplexed to implement the marine wireless network coverage project.
【学位授予单位】：海南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN92

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