Showing posts with label Ian F. Akyildiz. Show all posts
Showing posts with label Ian F. Akyildiz. Show all posts

Saturday, May 4, 2019

Abstract-Intelligent Environments based on Ultra-Massive MIMO Platforms for Wireless Communication in Millimeter Wave and Terahertz Bands



Millimeter-wave (30-300 GHz) and Terahertz-band communications (0.3-10 THz) are envisioned as key wireless technologies to satisfy the demand for Terabit-per-second (Tbps) links in the 5G and beyond eras. The very large available bandwidth in this ultra-broadband frequency range comes at the cost of a very high propagation loss, which combined with the low power of mm-wave and THz-band transceivers limits the communication distance and data-rates. In this paper, the concept of intelligent communication environments enabled by Ultra-Massive MIMO platforms is proposed to increase the communication distance and data-rates at mm-wave and THz-band frequencies. An end-to-end physical model is developed by taking into account the capabilities of novel intelligent plasmonic antenna arrays which can operate in transmission, reception, reflection and waveguiding, as well as the peculiarities of the mm-wave and THz-band multi-path channel. Based on the developed model, extensive quantitative results for different scenarios are provided to illustrate the performance improvements in terms of both achievable distance and data-rate in Ultra-Massive MIMO environments.

Tuesday, July 3, 2018

Abstract-Combating the Distance Problem in the Millimeter Wave and Terahertz Frequency Bands


Ian F. Akyildiz,  Chong Han,  Shuai Nie,

https://ieeexplore.ieee.org/document/8387211/

In the millimeter-wave (30-300 GHz) and terahertz (0.1-10 THz) frequency bands, the high spreading loss and molecular absorption often limit the signal transmission distance and coverage range. In this article, four directions to tackle the crucial problem of distance limitation are investigated, namely, a distance-aware physical layer design, ultra-massive MIMO communication, reflectarrays, and intelligent surfaces. Additionally, the potential joint design of these solutions is proposed to combine the benefits and further extend the communication distance. Qualitative and quantitative evaluations are provided to illustrate the benefits of the proposed solutions. The feasibility of mmWave and THz band communications up to 100 m in both line-of-sight and nonline- of-sight areas are demonstrated.

Friday, August 4, 2017

Abstract-Coverage and achievable rate analysis for indoor terahertz wireless networks


Anamaria Moldovan  Prasanth Karunakaran  Ian F. Akyildiz  Wolfgang H. Gerstacker

http://ieeexplore.ieee.org/document/7996402/

With the emergence of numerous novel dataintensive applications, the demand on fast wireless access is experiencing an unprecedented growth. Following this trend, the “Terabit era” is expected to become a reality in the near future. Terahertz technology is promising as an enabler due to its feature of an extremely high bandwidth. However, due to the high carrier frequency along with a high molecular absorption, the transmission distance is limited to a few meters only. In this work, the coverage problem and the achievable data rate performance of indoor THz wireless networks (THz-WNs) are investigated. In order to overcome the severe propagation loss and to improve the transmission range, a single frequency network (SFN) is advocated. The minimum individual user rate for different resource allocation schemes is analyzed, taking into account the effects of inter-symbol interference due to channel dispersion in the THz band and as a consequence of the SFN transmit protocol. Results demonstrate that the proposed SFN scheme is able to provide a high minimum achievable user data rate. The coverage probability increases from 25% when only a single access point (AP) is employed up to 95% when 20 APs are considered, for an output power of 1 W.

Tuesday, November 19, 2013

Abstract-A routing framework for energy harvesting wireless nanosensor networks in the Terahertz Band


Massimiliano Pierobon, Josep Miquel Jornet, Nadine Akkari, Suleiman Almasri, Ian F. Akyildiz

http://link.springer.com/article/10.1007/s11276-013-0665-y#

Wireless NanoSensor Networks (WNSNs) will allow novel intelligent nanomaterial-based sensors, or nanosensors, to detect new types of events at the nanoscale in a distributed fashion over extended areas. Two main characteristics are expected to guide the design of WNSNs architectures and protocols, namely, their Terahertz Band wireless communication and their nanoscale energy harvesting process. In this paper, a routing framework for WNSNs is proposed to optimize the use of the harvested energy to guarantee the perpetual operation of the WNSN while, at the same time, increasing the overall network throughput. The proposed routing framework, which is based on a previously proposed medium access control protocol for the joint throughput and lifetime optimization in WNSNs, uses a hierarchical cluster-based architecture that offloads the network operation complexity from the individual nanosensors towards the cluster heads, or nano-controllers. This framework is based on the evaluation of the probability of saving energy through a multi-hop transmission, the tuning of the transmission power of each nanosensor for throughput and hop distance optimization, and the selection of the next hop nanosensor on the basis of their available energy and current load. The performance of this framework is also numerically evaluated in terms of energy, capacity, and delay, and compared to that of the single-hop communication for the same WNSN scenario. The results show how the energy per bit consumption and the achievable throughput can be jointly maximized by exploiting the peculiarities of this networking paradigm