Minimum Energy Channel Codes for Nanoscale Wireless Communications

Abstract

It is essential to develop energy-efficient communication techniques for nanoscale wireless communications. In this paper, a new modulation and a novel minimum energy coding scheme (MEC) are proposed to achieve energy efficiency in wireless nanosensor networks (WNSNs). Unlike existing studies, MEC maintains the desired code distance to provide reliability, while minimizing energy. It is analytically shown that, with MEC, codewords can be decoded perfectly for large code distances, if the source set cardinality is less than the inverse of the symbol error probability. Performance evaluations show that MEC outperforms popular codes such as Hamming, Reed-Solomon and Golay in the average codeword energy sense.

Joint physical and link layer error control analysis for nanonetworks in the Terahertz band

“…In this paper, we have performed a joint physical and link layer analysis of error control techniques for nanonetworks. In particular, we have developed a mathematical framework to investigate the tradeoffs between error correction capabilities, energy consumption and latency, for a total of five different error control schemes, which included ARQ based on a 16-bit CRC, FEC based on Hamming (15,11) codes, constant and bound low-weight EPCs, and a hybrid EPC able to minimize the coding weight while guaranteeing a minimum distance to allow error correction. The analysis has capture the peculiarities of the THz-band channel, the physical layer, the network layer, the computational resources needed to implement the aforementioned error control techniques and the need of energy harvesting systems for perpetual operation.…”

“…In our case, however, given the impact of retransmissions, we focus on combining the benefits of FEC and EPC instead. This is achieved by designing a code that exhibits lowweight but at the same time can guarantee a target Hamming distance [15]. Ultimately, the idea is to jointly exploit the higher SNR provided by EPC with the lower SNR required by FEC to minimize the energy consumption, in such a way that the energy harvesting system does not become the bottleneck of the system.…”

“…Finally, for Hybrid EPC with k HEPC -bit-long words, able to simultaneously keep a low constant code weight w c and a code distance d c , the codeword length n HEPC is given by [15] n HEPC ¼…”

“…In particular, for a Hamming (15,11), the energy E HC consumed to encode k ¼ 11 bits into n ¼ 15 bits is given by,…”

“…More specifically, it was shown in [9] that the reduction of the average number of logic ones transmitted per packet results in a decrease in the overall molecular-absorption noise and interference powers. However, the reduction of the coding weight requires the transmission of longer data packets, which results in a higher energy consumption both at the transmitter and the receiver when compared to that of uncoded transmission [5,6,15]. Thus, there is a need for a unified crosslayer error-control analysis, tailored to the peculiarities of nanonetworks both on the nano-device side and the communication side.…”