Evaluation of digital baseband modulation schemes for molecular communication in nanonetworks

Molecular communications and nanonetworks become a popular and promising research direction recently. It uses molecules as the carrier to transmit information between nanomachines. Since the molecular communication is a novel communication paradigm, the communication principles and theories of it need to be re-considered and re-evaluated. In this paper, we describe four digital baseband modulation schemes for molecular communication systems, which modulate digital signals into the concentration of molecules. These modulation methods, including unipolar, polar, bipolar and Manchester methods, are investigated. The influences of the parameters such as symbol rate, distance, diffusion coefficient, are evaluated. The numerical results reveal that Manchester modulation scheme outperforms others in terms of bit error rate.