An improvement of Signal-to-Interference Ratio (SIR) at the base station of a wireless communication system can be obtained using a suitable choice of an array antenna. In this paper we consider Concentric Circular Antenna Array (CCAA) which can be used for adaptive antenna systems. A new adaptive algorithm, called least mean square-least mean Square (LLMS) algorithm, has been proposed for diff...

In this paper, Bit Error Rate (BER) performance of Feedback-type Adaptive Array Antenna (AAA) in Frequency Division Duplex/Direct Sequence Code Division Multiple Access system (FDD/DS-CDMA) with Mobile Station (MS) reception diversity will be investigated. The results include the effects of maximum Doppler frequencies (fd) and antenna element spacing at Base Station (BS) under flat fading and f...

A smart antenna system combines multiple antenna elements with a signal processing capability to optimize its radiation and/or reception pattern automatically in response to the signal environment through complex weight selection. The weight selection process to get suitable Array factor with low Half Power Beam Width (HPBW) and Side Lobe Level (SLL) is a complex method. The aim of this task is...

The design, construction and basic characteristics of an electronically steered, adaptive phased array antenna for land mobile satellite communications are described. The antenna system includes an array of six microstrip stacked patch antennas, each connected to an RF channel, which include an MMIC Low Noise Amplifier and a commercial silicon monolithic I-Q modulator. A 6-way microstrip combin...

AWiMAXmulti-cell system conforming the IEEE 802.16-2004 standard which supports multiple antennas and OFDM modulation is considered. Focusing on the uplink, we show that Signal to Interference plus Noise Ratio (SINR) degradation caused by fading impairments can be considerably reduced by exploiting adaptive modulation/coding techniques in conjunction with a non-uniform antenna array with optimi...

different methods exists for jamming mitigation and we should choose a method based an the jammer type and other parameters. one of the jammers is narrow band fm jammer and we use subspace projection techniques for the suppression of this type of jammer. in subspace projection technique, we estimate the if of signals and construct the subspace vector that is orthogonal to jammer vector by incre...

With the exponentially increasing demand for wireless communications the capacity of current cellular systems will soon become incapable of handling the growing traffic. Since radio frequencies are diminishing natural resources, there seems to be a fundamental barrier to further capacity increase. The solution can be found in smart antenna systems. Smart or adaptive antenna arrays consist of an...

This paper describes the original results obtained in the field of multi-beam annular ring antenna array pattern synthesis for the modes TM11 and TM12, by applying an iterative algorithm for phased arrays, which is able to produce low side-lobe levels patterns with multiple prescribed main lobes. The ring antenna analysis builds on the modified cavity model; this letter permits to take account ...

NAVSYS' High-gain Advanced GPS Receiver (HAGR) has been designed to take advantage of digital adaptive antenna array spatial-processing to enhance the accuracy of the GPS observations. The HAGR has the capability to create an optimized digital antenna pattern for up to eight GPS satellites simultaneously. This is used to perform dynamic beam-forming to the GPS satellites, in both static and mob...