Energy Optimal Coding for Wireless Nanosensor Networks

Wireless nanosensor networks (WNSNs), which consist of a lot of nanosensors with size of just a few hundred nanometers and are able to detect and sense new types of events at the nanoscale, are promising for a lot of unique applications like intrabody drug delivery systems, air pollution surveillance, etc. One important feature of WNSNs is that the nanosensors are highly energy-constrained, which makes it essential to develop energy efficient protocols for different layers of such networks. This paper focuses on a WNSN with on-off keying (OOK) modulation and explores the problem of transmission energy minimization in it. We first propose a general minimum transmission energy (MTE) coding scheme, which maps m-bit symbols into n-bit codewords with the least number of high-bits and thus results in the lowest energy consumption per symbol for any given m and n. We further determine the optimal setting of symbol length m and codeword length n in the MTE coding scheme so as to achieve the minimum energy consumption per data bit, which serves as the lower bound of transmission energy consumption in such WNSNs. Numerical results are provided to demonstrate the efficiency of the MTE coding scheme.