Low-weight Channel Codes for Error Prevention in Electromagnetic Nanonetworks in the Terahertz Band

Abstract

Nanonetworks consist of nano-sized communicating devices which can perform simple tasks at the nanoscale. Nanonetworks are the enabling technology for long-awaited applications in the biomedical, industrial and military fields. In this paper, the use of low-weight channel codes is proposed as a mechanism to prevent channel errors in nanonetworks. Rather than utilizing channel codes only to detect and correct transmission errors, it is shown that, by appropriately choosing the code weight, both molecular absorption noise and multi-user interference can be mitigated and, ultimately, the number of channel errors can be reduced beforehand. The performance of the proposed scheme is analytically and numerically investigated in terms of achievable information rate after coding and Codeword Error Rate (CER). An accurate Terahertz Band channel model, validated by COMSOL simulation, is used, and novel stochastic models for the molecular absorption noise in the Terahertz Band and for the multi-user interference in pulse-based Terahertz Band communication are developed. The results show that low-weight channel codes can be used to reduce the CER without compromising the achievable information rate. Moreover, it is shown that there is an optimal code weight, which depends on the network conditions, for which the information rate is maximized.