Multiple Channel Access Techniques for Diffusion-Based Molecular Communications

In this work, a transmission link between an arbitrary number of point sources and one spherical absorbing receiver is established considering diffusion-based molecular propagation in a three-dimensional environment filled with a fluid medium without flow. Therefore an equivalent discrete time channel model for multiuser communication is derived, molecule shift keying is used as modulation technique and an appropriate low-complexity adaptive threshold detector is implemented. For multiple channel access, molecular time division multiple access (MoTDMA) and as a main contribution molecular code division multiple access (MoCDMA) are introduced. The performances of the developed communication systems are analyzed in terms of bit-error-rate running numerical simulations.