In an ultrahigh frequency (UHF) radio frequency identification (RFID) system, the throughput can be greatly improved by collision resolution on a physical layer when tags collide, and high-performance coding technology can improve the bit error rate (BER) performance of the physical-layer separation. Most of the traditional physical collision resolutions focus on the code with a single subcarrier. This paper pays more attention to Miller code with multiple subcarriers and proposes a novel physical-layer separation method based on the Miller code. In this method, the separated collision signals are multiplied by clock signals with the same frequency as the subcarrier to complete the frequency shift. And then, a coherent demodulation and a low-pass filter are used to remove high-frequency separation noise. In the simulation, the Miller code with more subcarriers has lower BER than FM0 code with a single carrier. Especially when Miller 8 is selected, the separation efficiency and BER performance of the proposed method are 4 dB higher than those of the traditional XOR method at lower SNR.

中文翻译：

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基于米勒码的物理层UHF RFID标签冲突解决

在超高频（UHF）射频识别（RFID）系统中，当标签发生碰撞时，物理层上的冲突解决可以大大提高吞吐量，而高性能编码技术可以提高标签的误码率（BER）性能。物理层分离。大多数传统的物理冲突解决方案都将重点放在具有单个子载波的代码上。本文更加关注具有多个子载波的米勒码，并提出了一种基于米勒码的物理层分离新方法。在这种方法中，分离的碰撞信号与时钟信号相乘，时钟信号的频率与副载波相同，以完成频移。然后，使用相干解调和低通滤波器去除高频分离噪声。在模拟中 具有更多子载波的Miller码的BER比具有单个载波的FM0码的BER低。尤其是在选择Miller 8时，该方法的分离效率和BER性能比传统XOR方法的低SNR高4 dB。