Under-ice CDMA multiuser acoustic communications
Under-ice CDMA multiuser acoustic communications
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DOI：
10.1109/coa.2016.7535815
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
Yin Jingwei;Duan Pengyu;Zhu Guangping;Chen Wenjian;Liu Qiang
中科院分区：
文献类型：
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作者：
Yin Jingwei;Duan Pengyu;Zhu Guangping;Chen Wenjian;Liu Qiang
北极地区的科学考察和研究活动越来越多，其中北冰洋的相关研究尤为重要。由此可见，北极水声是保障军事存在和正常科研活动的重要支撑。2015年1月，中国在哈尔滨松花江进行了冰下声通信实验。零下20~30度的工作环境给冰下实验活动带来了巨大的挑战。由于冰下信道相对稳定，所有的冰下水声通信试验均实现了1公里距离、不同接收深度的低误码率通信。研究发现，越靠近冰层，冰下声学(UIA)通道结构越简单。时间反转镜(TRM)可以利用UIA信道的物理特性在多用户UIA通信中聚焦到期望的用户。主动平均声强(AASI)检测器可以同时估计同一频段用户的所有方位，从而通过矢量组合实现定向通信。为了提高多用户系统的容量，将基于TRM和AASI检测器的空分多址(SDMA)技术应用于码分多址(CDMAUIA)通信中。一种为水下信道中的直接序列扩频通信开发的方法被用来提取发送的码元。冰下数据显示，结合SDMA技术的码分多址系统最多可以同时支持12个用户。
More and more scientific investigations and research activities have been carried out in arctic region, among which the related research on the Arctic Ocean is particularly important. It can be seen that arctic hydro acoustics is the significant support to guarantee military presence and normal scientific research activities. Under-ice acoustic communication experimental was done in Songhua River, Harbin, China in January 2015. Minus 20~30 degrees work environment brings a great challenge to the under-ice experimental campaign. All of the under-ice acoustic communication tests achieve low bit error rate communication at 1km range with different received depth because of the relatively stable under-ice channel. It is found that the closer to the ice the simpler the under-ice acoustic (UIA) channel structure is. Time reversal mirror (TRM) can use the physical characteristics of the UIA channel to focus toward the desired user in multi-user UIA communication. Active average sound intensity (AASI) detector can estimate all azimuths of users with the same frequency band at the same time in order to achieve directional communication by vector combination. Space-division multiple-access (SDMA) based on TRM and AASI detector is used in code-division multiple-access (CDMA) UIA communication to increase the capacity of multiuser system. A method developed for direct sequence spread spectrum communications in an underwater channel are used to extract the transmitted symbols. Under-ice data shows that as many as 12 users can be supported simultaneously in CDMA system combined with SDMA technology.