Information capacity of pulse-based Wireless Nanosensor Networks

Nanotechnology is enabling the development of sensing devices just a few hundreds of nanometers in size, which are able to measure new types of events in the nanoscale by exploiting the properties of novel nanomaterials. Wireless communication among these nanosensors will boost the range of applications of nanotechnology in the biomedical, environmental and military fields, amongst others. Within the different alternatives for communication in the nanoscale, recent advancements in nanomaterials point to the Terahertz band (0.1-10.0 THz) as the frequency range of operation of future electronic nano-devices. This still unlicensed band can theoretically support very large transmission bit-rates in the short range, i.e., for distances below one meter. More importantly, the Terahertz band also enables very simple communication mechanisms suited to the very limited capabilities of nanosensors. In this paper, a new communication paradigm called TS-OOK (Time Spread On-Off Keying) for Electromagnetic Wireless Nanosensor Networks (WNSNs) is presented. This new technique is based on the transmission of femtosecond-long pulses by following an on-off keying modulation spread in time. The performance of this scheme is assessed in terms of information capacity for the single-user case as well as aggregated network capacity for the multiuser case. The results show that by exploiting the peculiarities of the Terahertz band, this scheme provides a very simple but robust communication technique for WNSNs. Moreover, it is shown that, due to the peculiar behavior of the noise in the Terahertz band, the single-user capacity and the aggregated network capacity can exceed those of the AWGN channel classical wireless networks, when the appropriate channel codes are used.