In orthogonal frequency-division multiplexing (OFDM)-based full-duplex (FD) systems, the terminal is allowed to transmit and receive signals simultaneously in the same frequency band. This leads to new challenges to pilot for channel estimation. The conventional pilot design methods are no longer effective for such systems. In this study, the authors propose a new practical pilot design method for OFDM-based FD systems and its performance is analysed in terms of the self-interference cancellation capability. Unlike the existing OFDM-based FD pilot design schemes, which require the channel to be constant during multiple continuous OFDM symbols, the authors' proposed scheme can be implemented in the block fading channel (i.e. channels that vary from one OFDM symbol to another). Besides, the optimal pilot pattern of the proposed scheme is studied. Their simulation results demonstrate the efficiency of the proposed pilot design.

中文翻译：

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基于OFDM的全双工系统的高效导频设计方案

在基于正交频分复用（OFDM）的全双工（FD）系统中，允许终端在同一频带中同时发送和接收信号。这给用于信道估计的导频带来了新的挑战。传统的飞行员设计方法对于这种系统不再有效。在这项研究中，作者提出了一种新的实用的基于OFDM的FD系统的导频设计方法，并根据自干扰消除能力对其性能进行了分析。与现有的基于OFDM的FD导频设计方案不同，该方案要求在多个连续OFDM符号期间信道必须保持恒定，而作者提出的方案可以在块衰落信道（即从一个OFDM符号到另一个OFDM符号变化的信道）中实现。此外，研究了该方案的最优导频模式。