Media.Player

A Method for Improving Spectrum Sensing/Efficiency in Cognitive Wireless Systems

Detailed Technology Description

Invention: To improve the sensing efficiency and/or the throughput for the SUs, this technology develops a new adaptation method that exploits self­interference suppression (SIS) capabilities in an SU device. Using this adaptation method, an SU can switch between a transmission-sensing (TS) mode and transmission-reception (TR) mode.  Background: In a DSA environment, wireless devices may be operated by primary (non-adaptive) and secondary (adaptive/cognitive) users. Secondary users (SUs) are allowed to access the spectrum opportunistically on a non-licensed  basis, provided that they do not harm the transmissions of primary users (PUs). Until recently, the idea that a wireless device can transmit and receive simultaneously on the same frequency channel, i.e., operate in full-duplex (FD) mode, was deemed impossible. The traditional scenario was that at a given time, a node can transmit or receive, but not both, which is often called half-duplex (HD) operation. The problem of achieving FD communications is that  the transmitted power from a given device is typically much larger than the received power of another signal that this device is trying to capture. While the device  is receiving  the second signal, its own transmitted signal is considered self-interference. The infeasibility of  FD  communications  has recently been  challenged in several efforts, which have successfully demonstrated the possibility of FD communications using self-interference suppression (SIS) techniques. The main novelty of these efforts is  to suppress self-interference to a level that enables FD communications. A commonly accepted scheme for protecting Pus from SU transmissions is the Listen-Before-Talk (LBT). In the LBT scheme, an SU device has to periodically interrupt its transmission (e.g., once every two seconds) and senses the channel for PU activity (transmissions). To do that, SUs must sense the PU communications activity over the wireless channel, an inherent problem of which in the traditional LBT scheme is that it results in a reduction in the SU throughput. Application: This product could be implemented into a wireless network that has a series of primary users and secondary users that implements a form of dynamic spectrum access. Primary interest would be in large scale telecommunication networks. Advantages: This invention has been demonstrated to be superior to the state-of-the-art in (a) theory, (b) simulations, and (c) using real data from a phantom. Our simulation results show orders of magnitude in improvement, as compared to traditional methods. Real results from phantom data closely replicate the performance of our simulations. •       proposed method does not suffer from the noise-bandwidth trade-off;•       can estimate very accurate field inhomogeneity maps over an arbitrary range of values;•       method can be optimized to the imaged material or tissue of interest;•       method does NOT require a phase unwrapping routine.  Lead Inventor: Marwan Krunz Contact Robert SleeperLicensing Manager, College of EngineeringRobertS@tla.arizona.edu220 W. 6th StreetUniversity Services Annex, 4th floorPO Box 210300Tucson, AZ  85721

*Abstract

None

*Principal Investigator

Name: Marwan Krunz, Professor

Department: Electrical & Computer Engineering

Name: Wessam Afifi ahmed, Graduate Assistant, Research

Department: Electrical and Computer Engineering

Country/Region

USA