Comparison of Channel Coding Schemes for Molecular Communications Systems

Abstract

Future applications for nano-machines, such as drug-delivery and health monitoring, will require robust communications and nanonetworking capabilities. This is likely to be enabled via the use of molecules, as opposed to electromagnetic waves, acting as the information carrier. To enhance the reliability of the transmitted data, Euclidean geometry low density parity check (EG-LDPC) and cyclic Reed-Muller (C-RM) codes are considered for use within a molecular communication system for the first time. These codes are compared against the Hamming code to show that an $\boldsymbol{s}=4$ LDPC (integer $\boldsymbol{s}\ge 2$ ) has a superior coding gain of 7.26 dBs. Furthermore, the critical distance and energy cost for a coded system are also taken into account as two other performance metrics. It is shown that when considering the case of nano–to nano-machines communication, a Hamming code with $\boldsymbol{m}=4$ , (integer $\boldsymbol{m}\ge 2$ ) is better for a system operating between $10^{-6}$ and $10^{-3}$ bit error rate (BER) levels. Below these BERs, $\boldsymbol{s}=2$ LDPC codes are superior, exhibiting the lowest energy cost. For communication between nano–to macro-machines, and macro–to nano-machines, $\boldsymbol{s}=3$ LDPC and $\boldsymbol{s}=2$ LDPC are the best options respectively.