This letter proposes a differential permutation index differential chaos shift keying (DPI-DCSK) modulation for wireless communications. The conventional PI-DCSK has the disadvantage of wasting transmission energy and the loss of system performance. In $M$ -ary DPI-DCSK, one chaotic sequence to be sent represents current modulated ${M}$ -ary symbol as well as the reference of next modulation symbol in a data frame, which can fully utilize the transmission energy with the same hardware implementation as PI-DCSK. The bit error performance of the proposed DPI-DCSK over the multipath Rayleigh fading channel is theoretically analyzed. The simulation results show that the proposed DPI-DCSK achieves a performance gain of more than 3 dB over PI-DCSK, especially in high-delay multipath fading channels. The performance advantage of the proposed scheme is also illustrated in practical ultra-wideband (UWB) channels. Thus, DPI-DCSK is an efficient alternative transmission scheme for chaos-based wireless communication, such as indoor applications of transmitted-reference UWB communications.

中文翻译：

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混沌通信系统差分置换指数DCSK调制

这封信提出了一种用于无线通信的差分置换指数差分混沌移位键控 (DPI-DCSK) 调制。传统的PI-DCSK存在传输能量浪费和系统性能损失的缺点。在 百万美元 -ary DPI-DCSK，一个待发送的混沌序列代表电流调制 ${M}$ -ary 符号以及数据帧中下一个调制符号的参考，可以充分利用传输能量，硬件实现与 PI-DCSK 相同。理论上分析了所提出的 DPI-DCSK 在多径瑞利衰落信道上的误码性能。仿真结果表明，所提出的 DPI-DCSK 比 PI-DCSK 实现了 3 dB 以上的性能增益，尤其是在高延迟多径衰落信道中。在实际的超宽带 (UWB) 信道中也说明了所提出方案的性能优势。因此，DPI-DCSK 是基于混沌的无线通信的有效替代传输方案，例如传输参考 UWB 通信的室内应用。