In-band full-duplex (IBFD) communication systems utilize self-interference cancellation to mitigate high-power self-interference caused by simultaneous transmission and reception at the same frequency in the digital baseband domain. Self-interference is distorted by transceiver nonlinearity. Thus, the IBFD literature includes reports of nonlinear self-interference cancellers developed to achieve better cancellation performance. However, there are no detailed theoretical studies analyzing the performance of nonlinear cancellers in IBFD systems. In this work, we develop a theoretical analysis technique for IBFD systems using parallel Hammerstein self-interference cancellers. The nonlinear characteristics of the system are expanded by a generalized Fourier series using orthonormal Laguerre polynomials. Then, the canceller’s performance and the system’s symbol error rate (SER) are analyzed using the obtained Fourier coefficients. The analytical results are compared with simulation results, demonstrating good correlation in a wide range of situations, from extremely nonlinear cases to good linear cases. Additionally, we show that the SER of the IBFD system is reduced by moderately nonlinearizing rather than linearizing the amplifier.

中文翻译：

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具有并行 Hammerstein 自干扰消除器的带内全双工无线电的理论分析


带内全双工（IBFD）通信系统利用自干扰消除来减轻数字基带域中同一频率上同时发送和接收所引起的高功率自干扰。自干扰因收发器非线性而失真。因此，IBFD 文献包括为实现更好的消除性能而开发的非线性自干扰消除器的报告。然而，目前还没有详细的理论研究来分析 IBFD 系统中非线性消除器的性能。在这项工作中，我们开发了一种使用并行 Hammerstein 自干扰消除器的 IBFD 系统的理论分析技术。使用正交拉盖尔多项式通过广义傅立叶级数扩展系统的非线性特性。然后，利用获得的傅里叶系数分析消除器的性能和系统的符号错误率（SER）。将分析结果与仿真结果进行比较，证明在各种情况下（从极其非线性的情况到良好的线性情况）都具有良好的相关性。此外，我们还表明，通过对放大器进行适度非线性化而不是线性化放大器，可以降低 IBFD 系统的 SER。