During the last two decades, Maximum Likelihood estimation (ML) has been used to determine Direction Of Arrival (DOA) and signals propagated by the sources, using narrowband array signals. The algorithm fails in the case of wideband signals. As an attempt by the present study to overcome the problem, the array outputs are transformed into narrowband frequency bins, using short time Fourier tran...

This paper provides an overview of some time-reversal (TR) techniques for remote sensing and imaging using ultrawideband (UWB) electromagnetic signals in the microwave and millimeter wave range. The TR techniques explore the TR invariance of the wave equation in lossless and stationary media. They provide superresolution and statistical stability, and are therefore quite useful for a number of ...

In general, narrowband systems require more complex terminals which require more space and power and are more costly than wideband terminals. Conversely, in general, wideband systems require more costly transmission facilities. Most Defense tactical users require wideband facilities at the present time due to weight, size, and power constraints. Nontactical users generally are located in an ofk...

The problem of restoring an image by its Fourier transform is considered when the Fourier transform contains phase distortions. The nature of these distortions and their values are arbitrary. The criterion for the quality of the phase distortion estimates is suggested. It can be used to select the image which is mostly like the true one. The nature of the true image is also arbitrary. The only ...

This article describes a method for estimating the subjective quality of wideband (7-kHz) speech solely from physical characteristics of terminals and networks. It enables efficient quality design and management of wideband speech communication services. The validity of this model was shown through experiments. Quality Assessment of Wideband Speech Communication Services Letters † NTT Service I...

As wireless communication applications require more and more bandwidth, the demand for wideband antennas increases as well. For instance, the ultra wideband radio (UWB) utilizes the frequency band of 3.1-10.6 GHz .In this paper we introduce a new multilayer microstrip antenna for ultra wideband applications. In order to achieve suitable bandwidth, the antenna size is fine for mobile application...

During the last two decades, Maximum Likelihood estimation (ML) has been used to determine Direction Of Arrival (DOA) and signals propagated by the sources, using narrowband array signals. The algorithm fails in the case of wideband signals. As an attempt by the present study to overcome the problem, the array outputs are transformed into narrowband frequency bins, using short time Fourier tran...

The application of MIMO communication systems in real environments will invariably require systems to operate over wideband channels. Although suitable techniques for processing wideband MIMO channels have been reported, their evaluation has mainly been based on simulation using modelled channels. In this paper we investigate some of the properties of wideband MIMO channels and compare the char...