AI 中文总结
针对基于OFDM的共生反向散射通信，提出正交频率码扩展（OFC）方案抑制直连链路干扰，用逐块正交码扩展减轻反向散射设备间干扰，开发非相干能量检测器，仿真验证该方案有低漏检概率和高频谱效率。
AI 中文摘要
我们为基于正交频分复用（OFDM）的共生反向散射通信（SBC）提出了一种无干扰的多反向散射设备（BD）接入方案。具体而言，引入正交频率码扩展（OFC）方案，发射机为BD预留空子载波，通过频移纳入其信息，有效抑制直连链路干扰（DLI）。由于共享子载波上的同时接入会引入反向散射设备间干扰（IBDI），采用逐块正交码扩展为每个BD分配唯一码字，在码域通过所有BD信号的正交传输减轻IBDI。我们开发了一种非相干能量检测器，并在瑞利衰落条件下根据平均漏检概率（PMD）和和速率分析其性能。仿真结果验证了OFC方案，与传统码辅助多BD接入方案相比，具有低PMD值和高频谱效率。
英文摘要
We propose an interference-free multi-backscatter device (BD) access scheme for orthogonal frequency division multiplexing (OFDM)-based symbiotic backscatter communication (SBC). Specifically, we introduce an orthogonal frequency-code spread (OFC) scheme in which the transmitter reserves empty subcarriers for BDs to incorporate their information through frequency shifting, which effectively suppresses direct-link interference (DLI). Since enabling simultaneous access over shared subcarriers introduces inter-backscatter device interference (IBDI), a blockwise orthogonal code-spread is applied to assign each BD to a unique codeword, thereby mitigating IBDI with orthogonal transmissions of all BD signals in the code domain. We develop a non-coherent energy detector whose performance is analyzed in terms of average probability of missed detection (PMD) and sum-rate under Rayleigh fading. The simulation results validate the OFC scheme and demonstrate low PMD values and high spectral efficiency compared to conventional code-assisted multiple-BD access schemes.
