The large available bandwidth of terahertz (THz) channels makes THz technology a promising approach to achieve very high data rates for future applications. In this paper, we characterize the THz channel using detailed measurement and analysis. Based on the results, we choose three THz bands in which atmospheric attenuation is smaller compared to other bands. We propose two rate adaptive downlink THz algorithms in which the modulation order is changed based on the channel properties of individual receivers. We demonstrate data rates of several Gbps per user while maintaining fairness.

We consider the problem of building a communication channel based on modulation of terahertz pulses. Given the constrained propagation properties of this spectrum, one of our goals is to determine the potential data rates achievable for different environmental conditions. To do this, we first present a detailed channel model based on measurements carried out on a terahertz time-domain system. We next simulate frequency-domain differential quadrature phase shift keying (FD-DQPSK) and Adaptive FD-DQPSK pulse modulation schemes. Finally, we simulate communication for different cities in winter and summer seasons where the primary channel impairment includes humidity. We show that data rates of well over 1 Tbit/s are achievable for all cases for distances of up to three meters. We also examine the error behavior of this transmission channel as a function of humidity and frequency band.

There are numerous scenarios where embedding static information into objects would prove to be very useful. For example, by embedding navigation information into the road surface we could enable driverless cars, similarly embedding information into major infrastructure such as building walls would enable easier classification of debris, and so forth. The key requirement is that the embedded information should survive as long as the infrastructure itself. We discuss the concept of wireless barcodes that allow us to achieve exactly this goal of tagging infrastructure. The barcodes are designed to be read at terahertz frequencies that allows good packing of information (bits/m). We use a TDoA (Time Difference of Arrival) technique to read the barcodes which provides robustness to wear and tear of the surface. This paper reports on the results of an experimental study that examines the challenges in building such barcodes and demonstrates the idea by constructing such a barcode.

We study the problem of wireless communication over indoor pulsed terahertz (THz) channels. First, we characterize the THz channel using measurements and derive a channel model. This channel model is then implemented in a Matlab simulator that we use to study different modulation schemes. In this paper, our focus is on examining frequency-domain differential phase shift keying (FD-DPSK) modulation schemes. We show that absorption due to water vapor leads to high bit error rate (BER). To combat this, we propose adaptive modulation schemes in which, depending on the humidity level of the channel and the distance between transmitter (Tx) and receiver (Rx), the system excludes some bands of the pulsed signal from the modulation scheme. Using FD-D64PSK modulation scheme and multiple transmitters in a time division multiplexing (TDM) channel, data rates as high as 5.994 Tbit/s can be achieved when the relative humidity (RH) is 0% over a distance of 50 cm. When the RH increases to 40% and 80% data rates decrease to 5.938 Tbit/s and 5.817 Tbit/s, respectively.