Low-complexity iteration-based interference cancellation in asynchronous physical-layer network coding
Low-complexity iteration-based interference cancellation in asynchronous physical-layer network coding
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DOI：
10.1049/iet-com.2014.0571
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发表时间：
2015-03
期刊：
影响因子：
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通讯作者：
Yixin Li;F. Zheng
中科院分区：
文献类型：
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作者：
Yixin Li;F. Zheng
当两个终端通过中间中继交换信息时，物理层网络编码（PLNC）通过允许并行分组传输来提高频谱效率。同步是分布式无线通信系统中最重要的问题之一。在基于时域（TD）的PLNC中，从用户终端发送的信号可以在不同的时间到达中继。由于采用了实际的脉冲成形和匹配滤波器，小数符号级延迟会引入符号间干扰。频分复用（OFDM）技术可以用来处理时间复杂度。然而，OFDM系统对载波频率偏移非常敏感，这将引入载波间干扰。在这项研究中，一种新的低复杂度的符号为基础的解码迭代干扰消除方案提出了基于TD和OFDM的PLNC。来自两个源的信号被分别解码，并且干扰被重构和消除。蒙特卡罗仿真结果表明，所提出的方案只需一次以上的迭代，就能显著提高系统的误比特率性能。
When two terminals exchange information through an intermediate relay, physical-layer network coding (PLNC) improves the spectrum efficiency by allowing cocurrent packet transmission. Synchronisation is one of the most important issues in distributed wireless communications systems. In time-domain (TD)-based PLNC, signals transmitted from user terminals may arrive the relay at different time. The fractional symbol level delay will introduces inter-symbol interference because of the use of practical pulse-shaping and matched-filter. Orthogonal-frequency division-multiplexing (OFDM) can be used to deal with time asynchrony. However, OFDM systems are very sensitive to carrier frequency offsets, which will introduce inter-carrier interference. In this study, a novel low-complexity symbol-based decoding iterative interference cancellation schemes are proposed for TD-based and OFDM-based PLNC. Signals from two sources are separately decoded, and interference is reconstructed and eliminated. Monte Carlo simulations show that the proposed scheme with over just one iteration can significantly improve the bit error rate performance.