Focusing optical beams on a target through random propagation media is very important in many applications such as free space optical communications and laser weapons. Random media effects such as beam spread and scintillation can degrade the optical system’s performance severely. Compensation schemes are needed in these applications to overcome these random media effects. In this research, we ...

This paper introduces a novel architecture of a multi-beam adaptive beamformer for SDMA (space division multiple access) applications. Combined with a 5.8 GHz eight-element RF front-end, digital beamforming performance using the proposed frequency-domain multi-beam beamformer is demonstrated in post processing. The DOA estimation based on the ESPRIT algorithm and simultaneous dual-beam forming ...

Nonlinear antennas combine advances in nonlinear dynamics, active antenna design, and analog microelectronics to generate beam steering and beam forming across an array of nonlinear oscillators. Nonlinear antennas exploit two phenomena typically shunned in traditional designs: nonlinear unit cells and interelement coupling. The design stems from nonlinear coupled differential equation analysis ...

Recent developments in the field of wireless communication systems are due to the development in field of Smart Antennas. These Antennas are capable of fulfilling high demand of data rate, capacity and also offers good quality of services to wireless communication systems. These characteristics can be obtained by increasing the gain of antenna in the desired direction; which is achieved by dire...

LMS algorithm is simple and is well suited for continuous transmission systems since it is a continuously adaptive algorithm. However, it is not known for its convergence speed in the presence of Gaussian, spatially white, of null mean and variance which has prompted people to use other complicated algorithms. In the above scenario LMS has maximum mean square error and minimum error stability. ...

Faculty of Sciences Department of Computer Science

Phased-array feeds are possibly the best option for the 240 to 1200 MHz band on VLA antennas due to their wide bandwidth and relatively small size. One of the greatest assets of these antennas is the ability to produce a shaped beam by appropriately phasing the elements allowing in some cases nearly uniform aperture illumination with minimal ground-directed spillover. The beam-forming propertie...

We demonstrate a system to integrate adaptive beam-forming and auditory features in order to improve speech recognition accuracy in noisy environments. Adaptive beam-forming based on a microphone array can utilize spatial information to improve the sound recording signal-to-noise ratio (SNR) on a focused speaker for robust speech recognition. Auditory features based on modeling the signal proce...

Smart antenna technology has the potential to significantly increase the efficient use of the spectrum in wireless communication applications in comparison to the existing methods in use. Through intelligent control of the transmission and reception of signals, capacity and coverage in mobile wireless networks can be significantly improved. Smart antenna is one of the most promising technologie...