We describe and analyze adaptive antenna array technology to improve naval communications systems to beyond line-of-sight at microwave frequencies by using the ducting layer as a leaky waveguide and the adaptive array to resolve and coherently combine multipath in this layer.

In this paper, we compare the increase in range with multiple-antenna base stations using adaptive array combining to that of phased array combining. With adaptive arrays, the received signals at the antennas are combined to maximize signalto-interference-plus-noise ratio (SINR) rather than only form a directed beam. Although more complex to implement, adaptive arrays have the advantage of high...

This paper presents brief account on smart antenna (SA) system. Smart or adaptive antenna arrays consist of an array of antenna elements with signal processing capability that optimizes the radiation and reception of a desired signal dynamically. SAs can place nulls in the direction of interferers via adaptive updating of weights linked to each antenna element. SAs thus cancel out most of the c...

Space Time Adaptive Processing (STAP) applied on signal received from different configurations of real elements using D3LS (Direct Data Domain Least Squares). We will discuss the impact of each typical element-missing on the performance of this approach and the precision of the estimated strength of the SOI. We are interested in five different antenna configurations which are uniform linear equ...

Mobile worldwide interoperability for microwave access (Mobile WiMAX) based on IEEE 802.16e is a standard designed for metropolitan area networks (MAN) that cover an area wider than that covered by local area networks. Commercial WiMAX services are already available in some countries and regions. Services in Japan are scheduled to start in 2009. Mobile WiMAX supports “one-cell frequency reuse,”...

The packet throughput is analyzed for a slow FH/SSMA packet radio network with adapt ivc o i i t e r i r m array and packet combznzng in a Rayleigh fading channel with shadowing. The packet throughput is defined as the average number of captured packets per slot. To enhance the throughput performance, the adaptive antenna array and packet combining are employed. As a random access protocol, slo...

This paper presents an adaptive technique to extract the signal of interest (SOI) arriving from a known direction in the presence of strong interferers using a single snapshot of data. The antenna elements in this method can be nonuniformly spaced and there can be mutual coupling between them. In addition, near-field scatterers can also be present. First, the voltages induced in the antenna ele...

Broadcasting antenna array null filling is a very challenging problem for antenna design optimization. This paper compares five antenna design optimization algorithms (Differential Evolution, Particle Swarm, Taguchi, Invasive Weed, Adaptive Invasive Weed) as solutions to the antenna array null filling problem. The algorithms compared are evolutionary algorithms which use mechanisms inspired by ...

The problem of designing a class of linear antenna arrays with broad nulls against interfering sign& Of variable direction of qrival is considered. The problem is formulated in an appropriate signal space selected for an efficient representation of array signals of specified angular occupancy. The array-weight vector is then chosen to be orthogonal to this space. The approach is seen to yield a...

In this paper, smart antennas are antenna array use to empathize spatial signal such as DOA of the signal and used to find beamforming vectors and locate the antenna ray in the desired direction of target. Beam formed adaptive algorithms allow the antenna to steer the beam in desired direction of interest while cancelling the obtrusive signals. The prompt growth of smart antenna makes use of di...