大容量宽带卫星通信系统的下行高效传输方法

发布时间：2018-02-01 06:09

  本文关键词： 宽带卫星通信 频分复用 连续波时分复用 准正交时分复用　出处：《西安交通大学学报》2017年03期 　论文类型：期刊论文

【摘要】：针对基于非再生式星上处理的大容量宽带卫星通信系统下行链路采用频分复用(FDM)传输方式效率低、性能差的问题,提出并论证了两种特殊的连续波时分复用(CWTDM)方法——分帧交织叠接相加法(AFO)和准正交时分复用(QOTDM)法。首先,两种方法均先将待传输的各路基带复信号采样量化;然后,AFO方法对量化信号进行分帧叠接相加后加上帧头构成复用帧进行下行传输,QOTDM方法采用样点交织的时分复接再添加同步序列后转化为连续信号进行传输。AFO方法对信号复接、分接的处理简单;QOTDM方法复接时只需每路缓存一个样点,有利于实现更大容量的星上交换。与FDM下行传输方式相比,这两种方法的功率效率更高、链路特性更好。仿真结果表明,相较FDM传输方式,QOTDM方法的256个载波下的信干比可提高10dB,子信道隔离度可达到实用要求。
[Abstract]:In order to solve the problem of low efficiency and poor performance in the downlink of large capacity broadband satellite communication system based on non-regenerative on-board processing, frequency division multiplexing (FDM) transmission mode is used. In this paper, two special CWTDMs are proposed and demonstrated, namely, framing interleaved overlapping addition (AFO) and quasi orthogonal time division multiplexing (QOTDM). The two methods first sample and quantize each baseband complex signal to be transmitted. Then, the AFO method overlaps the quantized signals and then adds a frame head to constitute a multiplexed frame for downlink transmission. The QOTDM method uses the time division multiplexing method of sample interleaving to add the synchronization sequence and then converts the signal into a continuous signal for transmission. The signal multiplexing method is simple and the demultiplexing process is simple. When the QOTDM method is multiplexed, only one sample is needed for each buffer, which is beneficial to the realization of larger on-board switching. Compared with the downlink transmission mode of FDM, the two methods have higher power efficiency. The simulation results show that the signal-to-interference ratio under 256 carriers can be improved by 10 dB compared with the 256 carriers of FDM transmission mode, and the subchannel isolation can meet the practical requirements.
【作者单位】： 西安电子科技大学综合业务网国家重点实验室;中国电子系统工程公司研究所;
【基金】：国家自然科学基金资助项目(61301170) 中国空间技术研究院基金资助项目(0883383005)
【分类号】：TN927.2
【正文快照】： 网络出版地址:http:∥www.cnki.net/kcms/detail/61.1069.T.20170113.1018.002.html随着全球信息化的高速发展,急剧增长的市场需求迫使卫星通信不断朝着大容量、宽带化的方向发展[1]。然而,对于大容量宽带卫星通信系统而言,若采用再生式星上处理(OBP),虽然能够支持各种形式的，

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