Significant inter-symbol interference (ISI) challenges the achievement of reliable, high data-rate molecular communication via diffusion. In this paper, a hybrid modulation based on pulse position and concentration is proposed to mitigate ISI. By exploiting the time dimension, molecular concentration and position modulation (MCPM) increases the achievable data rate over conventional concentration and position-based modulations. In addition, unlike multi-molecule schemes, this hybrid scheme employs a single-molecule type and so simplifies transceiver implementations. In the paper, the optimal sequence detector of the proposed modulation is provided as well as a reduced complexity detector (two-stage, position-concentration detector, TPCD). A tractable cost function based on the TPCD detector is proposed and employed to optimize the design of the hybrid modulation scheme. In addition, the approximate probability of error for the MCPM-TPCD system is derived and is shown to be tight with respect to simulated performance. Numerically, MCPM shows improved performance over standard concentration and pulse position-based schemes in the low transmission power and high bit-rate regime. Furthermore, MCPM offers increased robustness against synchronization errors.

翻译：利用时间尺寸、分子浓度和位置调制(MCPM)提高常规浓度和基于位置的调制(MSPM)的可实现数据率;此外,与多分子计划不同,这种混合计划采用单一分子型,从而简化了传输器的安装;在本文中,根据脉搏位置和浓度,建议采用混合调制混合调制(MSI),以缓解三氧化锡;通过利用时间尺寸、分子浓度和位置调制(MCPM),提高常规浓度和基于位置的调制(MCPM)的可实现的数据率;此外,与多分子计划不同,这种混合计划采用单一分子型类型,从而简化了传输器的安装;在文件中,提供拟议调制的最佳序列探测器,以及一个降低复杂性的探测器(两阶段、位置浓缩探测器、TPCD);根据TPCD探测器提出并使用可移动的成本功能,以优化混合调制的设计;此外,MCPM-TPCD系统的误差概率接近于模拟性性性能,M显示在标准浓度和基于脉冲定位的系统上性能过强的性能和低能量-同步性能改进。