In this letter, we present a new approach of using time-modulated phased arrays to synthesize multicarrier directional modulation (DM) symbols for physical-layer security. In particular, the modulated waveform synthesis is achieved with the careful design of the switching time sequences, instead of in digital baseband; thus, reducing the peak-to-average power ratio of signals going through the radio frequency (RF) chain, and only a single RF chain is required here. The operation principle and synthesis approach are elaborated and demonstrated. In addition, the efficacy of the proposed DM approach is validated via the bit-error-rate (BER) metric.

中文翻译：

---

使用时间调制相控阵的多载波定向调制符号合成

在这封信中，我们提出了一种使用时间调制相控阵来合成多载波定向调制（DM）符号以实现物理层安全性的新方法。特别是，通过精心设计切换时间序列，而不是在数字基带中，可以实现调制波形合成。因此，降低了通过射频（RF）链的信号的峰均功率比，这里只需要一个RF链。详细阐述和演示了其工作原理和综合方法。另外，通过误码率（BER）度量验证了所提出的DM方法的有效性。