  Molecular communication underpins nano-scale communications in
nanotechnology. The combination of multinanomachines to form nano-networks is
one of the main enabling methods. Due to the importance of source localization
in establishing nano-networks, this paper proposes a cooperative source
localization method for Molecular Communication via Diffusion (MCvD) systems
using multiple spherical absorption receivers. Since there is no exact
mathematical expression of the channel impulse response for multiple absorbing
receivers, we adopt an empirical expression and use Levenberg-Marquardt method
to estimate the distance of the transmitter to each receiver, based on which
the location of the transmitter is obtained using an iterative scheme where the
initial point is obtained using a multi-point localization method. Particle
based simulation is carried out to evaluate the performance of the proposed
method. Simulation results show that the proposed method can accurately
estimate the location of transmitter in short to medium communication ranges.
