This paper presents an adaptive weight computation algorithm for a robust array antenna based on the sample matrix inversion technique. The adaptive array minimizes the mean output power under the constraint that the mean square deviation between the desired and actual responses satisfies a certain magnitude bound. The Lagrange multiplier method is used to solve the constrained minimization pro...

AbstructAdaptive beamforming techniques are now widely used to reject interference Uammerklutter) signals in radar, communication, and sonar applications. In adaptive arrays using the sample matrix inversion (SMI) algorithm, inadequate estimation of the covariance matrix results in adaptive antenna patterns with high sidelobes and distorted mainbeams. In this paper, a method is proposed to prec...

Adaptive antenna arrays have been proposed to mitigate strong interference and multipath in Global Navigation Satellite Systems (GNSS) receivers. However, the high cost of an entire front-end and limited signal processing resources make large (or oversampled) antenna array a luxury for GNSS receivers. Therefore, a low cost adaptive array processing strategy by subarray selection is proposed in ...

Recently, a smart antenna, i.e., a blind adaptive antenna array, has attracted much attention to improve the capacity of a future code-division multiple-access wireless communications system. It has been demonstrated (Tanaka et al., 2000) that there is significant improvement in data demodulation through lab simulations and field experiments by employing a smart antenna of multiple elements. Ho...

Smart antennasystems have received much attention in the last few years because they can increase system capacity by dynamically tuning out interference while focusing on the intended user. In this paper, we focused our research on the performance of two kinds of smart antenna receivers. An analytical model is proposed for evaluating the BER performance using a closed-form expression. Also, for...

In a commonly accepted usage scenario, a cognitive radio appears as a secondary user of certain spectrum which is licensed to another, primary system. A prominent example of cognitive system is a mesh network operating under the interference from primary system. For such a scenario, we propose techniques for efficient secondary usage of spectrum, which rely on the adaptive array antenna in orde...

This paper presents a design for a transmitting antenna array comprised of mobile antenna elements, where the Global Positioning System (GPS) is used to estimate the current location and velocity of those elements. GPS is also used to synchronize the clocks carried by the mobiles. With this information, a central algorithm can control the phase of the radio signal radiated from each element so ...

This paper presents a software defined radio (SDR) implementation based on programmable digital signal processors (DSP) for smart antenna systems (SAS). We evaluate adaptive beamforming algorithms, namely nonblind-type least mean square (LMS) and blind-type constant modulus (CM) using TI TMS320C6000 high performance DSPs for cdma2000 reverse link. Adaptive beamformers are implemented using TI c...

In broadband wireless communication, the adaptive antenna array (AAA) is combined with orthogonal frequency division multiplexing (OFDM) to combat the inter-symbol interference (ISI) and the directional interferences. One of the two main techniques which are used in OFDM systems is called Pre-FFT, where an optimum beamformer weight set is obtained in time domain before Fast Fourier Transform (P...