DOA Estimation of a Wideband Signal Using a 2-D Array Antenna with Spatial Processing Capability

This paper describes investigations into Direction–Of–Arrival (DOA) estimation of a wideband signal by a two–dimensional array antenna, which employs only spatial signal processing for beam forming. The elements of this array are arranged in a horizontal rectangular lattice to steer a beam in azimuth over a wide frequency band. By applying the concept of interpolated array, a composite covariance matrix is produced. This composite covariance matrix is a simple addition of covariance matrices of narrowband virtual arrays, being stretched or compressed versions of a nominal array, all featuring the same radiation pattern. DOA is estimated by eigen–decomposition of the composite covariance matrix using the narrowband MUSIC algorithm. The performance of the proposed DOA estimation method is demonstrated by computer simulations. The obtained results indicate that the two–dimensional array provides better estimation of DOA than the one–dimensional one when the interpolated array technique in conjunction with the MUSIC algorithm is applie

Exploiting multi-verse optimization and sine-cosine algorithms for energy management in smart cities

[EN] Due to the rapid increase in human population, the use of energy in daily life is increasing day by day. One solution is to increase the power generation in the same ratio as the human population increase. However, that is usually not possible practically. Thus, in order to use the existing resources of energy efficiently, smart grids play a significant role. They minimize electricity consumption and their resultant cost through demand side management (DSM). Universities and similar organizations consume a significant portion of the total generated energy; therefore, in this work, using DSM, we scheduled different appliances of a university campus to reduce the consumed energy cost and the probable peak to average power ratio. We have proposed two nature-inspired algorithms, namely, the multi-verse optimization (MVO) algorithm and the sine-cosine algorithm (SCA), to solve the energy optimization problem. The proposed schemes are implemented on a university campus load, which is divided into two portions, morning session and evening session. Both sessions contain different shiftable and non-shiftable appliances. After scheduling of shiftable appliances using both MVO and SCA techniques, the simulations showed very useful results in terms of energy cost and peak to average ratio reduction, maintaining the desired threshold level between electricity cost and user waiting timeUllah, B.; Hussain, I.; Uthansakul, P.; Riaz, M.; Khan, MN.; Lloret, J. (2020). Exploiting multi-verse optimization and sine-cosine algorithms for energy management in smart cities. Applied Sciences. 10(6):1-21. https://doi.org/10.3390/app1006209512110

Improving MIMO system capacity by compensating mutual coupling in transmitting/receiving array antennas

The effect of mutual coupling compensation for transmitter and receiver antenna arrays to improve perfrmance of a MIMO system was investigated by using the inverse coupling matrix approach. Using this approach the MIMO capacity can be access as a function of spacing and number of elements in the receiving and transmittng antenna arrays. The five cases concerning the effect of mutual coupling in linear arrays of dipoles on performance of a MIMO system were demonstrated. It was revealed that the MIMO capacity was reduced when mutual coupling effects become pronounced. It was shown that the effect of coupling can be compensated using the information obtained from the mutual impedance matrices for transmitting/receiving arrays

Fully spatial wide-band beamforming using a rectangular array of planar monopoles

This paper describes a spatial beamformer which by using a rectangular array antenna steers a beam in azimuth over a wide frequency band without frequency filters or tap-delay networks. The weighting coefficients are real numbers which can be realized by attenuators or amplifiers. A prototype including a 4 x 4 array of square planar monopoles and a feeding network composed of attenuators, power divider/combiners and a rat-race hybrid is developed to test the validity of this wide-band beamforming concept. The experimental results prove the validity of this wide-band spatial beamformer for small size arrays

Wideband beam and steering using a rectangular array of planar monopoles

This article presents the design of a wideband rectangular array of planar monopoles, which is able to steer its beam and nulls over a wide frequency band using real-valued weights. These weights can be realized in practice by amplifiers or attenuators leading to a low cost development of a wideband array antenna with beam and null steering capability. The weights are determined by applying an inverse discrete Fourier transform to an assumed radiation pattern. This wideband beam and null forming concept is verified by full electromagnetic simulations which take into account mutual coupling effects between the array elements