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Adaptive beamforming is critical in high performance radar and wireless communications applications. This paper presents a study of adaptive beamforming for arbitrary array by applying the powerful and versatile particle swarm optimization (PSO). Numerical experiments for sidelobe suppression, nulling, null steering and array failure correction have demonstrated that the presented PSO approach is...
In this study, a wideband direct data domain genetic algorithm beamforming approach to adaptive processing using fast Fourier transform is presented. Received wideband signals are decomposed to a set of frequency narrow subbands using fast Fourier transform. Each subband could be treated separately after being transformed to a reference frequency using the steering vector transformation technique;...
In front of the conventional loudspeaker array, the sound pressure level of uniform distribution in a linear listening area is constrained by frequency range. In the previous papers, we have realized SPL distribution evenly from 200 to 500 Hz by controlling the phase of linear loudspeakers. However, with the increasing of frequency, we have to consider about the directivity of single loudspeaker....
Distributed beamforming is a communication method in wireless sensor networks (WSNs) where the sensor nodes collaboratively create a virtual antenna to direct their radiating power towards the direction of an intended destination. This method could increase the transmission range of the network and save the sensors' energy. However, due to the random locations of the sensor nodes, the beampattern...
Time-modulation is applied to an array pattern by alternating a beamformer between two sets of beamforming coefficients. These are selected so signals arriving in the sidelobes are BPSK modulated by the beam-switching while signals in the main lobe are not. This technique enables sidelobe blanking using a single beamformer, which is simpler than other approaches.
The performance degradation of a wideband channel is due to the high occupied bandwidth and the overlapping it creates with other communication services. In situations, such channels are also configured as multi input single output (MISO) system. Here, data rate is high resulting in co-channel interference (CCI) and inter symbol interference (ISI). As a result, the requirement of interference mitigation...
This paper proposes solution to optimize the peak side lobes level (PSLL) in a distributed random antenna array (RAA) when locations of the nodes in the array cannot be manipulated. Using the conventional beam forming method, RAA produces a poor beam pattern with high side lobe level, which greatly reduces the performance and the efficiency of the antenna. Existing literature focuses on finding the...
Fault tolerance is a critical property for many communication systems, whether it is commercial or governmental, related to defense or aerospace, be it terrestrial, airborne or in space. Redundancy is a common approach to fault-tolerance but incurs extra cost, mass, and overall system complexity. Self-healing systems are appealing because they avoid some of the disadvantages of redundancy while allowing...
This paper compares the Simple Genetic Algorithm (SGA) to a Triallelic Diploid Genetic Algorithm (TDGA) in evolving an anti-jamming beamforming array in situ. The SGA and TDGA are both able to find reasonable beamformer settings to thwart two jammers while allowing reception of a signal of interest (SOI). The array operates in the 2.4 GHz 802.11g band, and the results presented are applicable to other...
Collaborate beamforming in wireless sensor networks (WSNs) is a concept of using beamforming technology to establish link in the networks. It can effectively increase the transmission distance and improve the energy efficiency of the networks. Due to random deployment of the sensor nodes in the networks, proper assignment for the sensor nodes in wireless sensor networks is vital to achieve better...
This paper presents a genetically evolved antijamming beamforming array. The performance of a genetic algorithm (GA) is evaluated in situ as part of a hardware-in-the-loop optimization system. The GA was able to find reasonable beamformer settings to thwart a maximum of three stationary jammers while allowing reception of a signal of interest. Although the array operates in the 2.4 GHz 802.11g band,...
The suppression of random interference nulling for uniform circular array using an improved binary coding method is investigated in this paper, which is based on Genetic Algorithm (GA) applied to smart antenna beamforming. The code lengths of the algorithm's least amplitude significant bits and least phase significant bits are analyzed, and their impacts on algorithm's performance are discussed. As...
Antenna array systems are important components of modern radar and wireless communication systems. By controlling the array through a real-time optimization process, the adaptive techniques diminish the impact of system component noise and mitigate the effects of interfering radiation to ensure the delivery of a maximum fidelity signal. This paper deals with the possibilities to cancel unwanted signals...
The beampattern of MIMO (Multiple-input Multiple-output) radar is the product of transmitter and receiver beam pattern. Exploiting uniform linear array, the beampattern has no grating lode when a certain relation between the space of transmitter element and receiver element is met. Moreover, this kind of collocation takes on maximum virtual array aperture. Exploiting non-uniform linear array, the...
If the elements in an ultrasound array are damaged, the beamforming performance and imaging quality (contrast and resolution) will be significantly reduced due to the distorted beam pattern with for example, a significant increase of sidelobe level. Defective elements can be detected through either in-direct impedance measurement or direct monitoring of the acoustic output using fibre Bragg grating...
In, a Hybrid Smart Antenna System that enables low-cost adaptive beamforming for the 60 GHz applications is presented. This algorithm relies on the use of highly directive antennas with their beams oriented towards different directions to lower the number of elements used for beamforming, and to achieve uniform coverage in the desired range, hence resulting in a significantly lower cost. In, a genetic...
This paper presents the design, simulation, and fabrication of two RF steerable beamforming networks (BFN) using a 4×4 Butler Matrix for the 3.15 GHz (S-band) and an 8×8 Rotman Lens for the 6.3 GHz (C-band). Both beamforming networks are intended for the Intelligent Transportation Systems (ITS). Although the frequency range likely to be allocated to such systems is 63 GHz, where the short transmission...
Reconfigurable aperture (RECAP) antennas consist of a regular array of reconfigurable elements confined to an aperture, representing a generalization of the reconfigurable antenna concept. RECAPs have the potential of supporting operations like beamforming, null steering, interference suppression, adaptive matching, and frequency and bandwidth agility in a single aperture. Although very complex RECAP...
An improved particle swarm optimization (PSO) algorithm is proposed for the fast array failure correction in digital beam-forming of arbitrary arrays. One of the key advantages of PSO, versus genetic algorithm (GA), is exploited in this paper, to arrive at similar results in a much shorter time. This flexible PSO algorithm can be employed for arrays of different configurations, and requires less computational...
In this paper we propose a novel genetic algorithm called immunity genetic algorithm (IGA) based on stochastic crossover evolution to solve the synthesis problem of thinned arrays. Our crossover operator is a variant of the known GA operator. A new expression of the array factor for a specific number of elements N is expressed as a linear discrete cosine transform (DCT). Using IGA to generate thousands...
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