Diffusion-Based Digital Molecular Communication

• Main Authors: Ling-San Meng, 孟令三
• Other Authors: 葉丙成
• Format: Others
• Language: en_US
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/78944210848236187831

博士 === 國立臺灣大學 === 電信工程學研究所 === 100 === Molecular communication, being one of the most promising communication mechanisms among nanoscale devices, has attracted considerable interests from the communication theorists and research communities. Diffusion-based molecular communication refers to the situation where molecules reach the destination relying solely on the laws of molecular diffusion. In this thesis, two different families of digital molecular communication are identified, namely coherent and non-coherent digital molecular communication. For each family of molecular communication, the fundamental framework for designing a digital communication system based on molecular diffusion is proposed. Such a framework is the first to analytically take into account the effect of channel memory with arbitrary order, which is a key property of the diffusion channel that most of the existing literature fails to capture. Based on an information-theoretic approach, an information-optimal receiver detection scheme that can achieve maximum mutual information is proposed. A low-complexity receiver detection scheme without the knowledge of a priori information is also proposed. Results show that the low-complexity receiver detection scheme guarantees both families of molecular communication to be operated without failure in the case of infinite channel memory. A channel capacity of 1 bit per channel utilization can be ultimately achieved by extending the duration of the signaling interval. Under the proposed framework of digital molecular communication systems, various diversity techniques for Multi-Input Multi-Output (MIMO) transmissions are proposed to combat the effect of Multi-User Interference (MUI). The transmit diversity, selection combining, Maximum Ratio Combining (MRC), decision fusion, and Spatial Multiplexing (SM) for MIMO molecular communication are formulated and analyzed to obtain the error probability. The notion of virtual MIMO to achieve cooperative diversity is also investigated and proposed to be applied to molecular communication. Numerical results show the proposed diversity techniques can significantly lower the error probability in the presence of MUI. Further performance improvement can be obtained by properly allocating the molecules among the transmission nodes if the Channel State Information (CSI) is available at the transmitting end.