The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The performance of adaptive beamformer will degrade in the case of jammer motion and shaking platform. In order to improve the performance of adaptive beamformer, an improved null broadening adaptive beamforming method is proposed. The proposed method is realized by the reconstruction of interference-plus-noise covariance matrix. Null broadening can be obtained by the proposed method and the null...
Two dimentional (2D) adaptive digital beamforming is one of the promising smart antenna technologies to meet the rapidly increasing demands for more capacity of satellite communication systems. However, the conventional 2D adaptive digital beamforming algorithms have the jitter and high sidelobe problems especially when the number of antenna elements is large. In this paper, a penalty function based...
MICROWAVE beamforming (MBF) is advantageous over digital beamforming (DBF) in several regards [1]. First, due to a lower number of RF down-converters and analog to digital converters (ADC), MBF structures have lower size, weight and battery power consumption. Second, due to weighting and combining of signals in the analog domain and avoiding quantization errors, MBFs have higher dynamic and suppression...
A robust adaptive beamforming algorithm based on least square constant modulus algorithm (LSCMA) is proposed in this paper. The CMA adaptive array was designed to lock onto the desired signal having the constant modulus property. The proposed algorithm employs both the DOA information as well as the constant modulus property of the signals. This enables the beamformer to avoid self-cancellation caused...
Massive MIMO enables the improvement on the transmission rate without increasing the burden on the signal processing by employing a large number of antennas at a base station (BS). However, it is reported that CSI estimation itself has a large overhead when considering massive MIMO. The authors have proposed analog-digital hybrid massive MIMO configuration which eliminates CSI estimation itself by...
This paper proposes a novel transmission technique for Inter-Cell Interference Cancelation (ICIC) in cellular networks. The new technique utilizes the Conjugate Gradient Method (CGM) for calculating the optimal weight vector for the transmitting antenna array system operating at a base station. The weight vector provides a maximum gain along the direction of a target mobile device and deep nulls to...
In this work, a cost-effective radio frequency (RF) beamforming array is used to orient and suppress directional interfering signals. With this frontend, both the multiple signal classification (MUSIC) algorithm used in direction-of-arrival (DOA) estimation and the optimizaoion based power inversion (PI) algorithm used to suppress the interfering signal can be significantly simplified. With a RF output,...
IEEE 802.11 Wlan networks are constantly challenged for maximum overall service performance and new mobility applications: real-time, interactive communications and presence analytics. They require a solid design approach that considers but not limited to: highly varying characteristics of dense environments, technology advances, feasibility of study hypotheses, and overall service design best practices...
Channel mismatch has become a serious limit to further improve the anti-jamming performance on satellite navigation antenna arrays receivers. Consistency degree of each channel could directly determine the anti-jamming performance. In order to analyze and confirm the channel consistency indexes, this paper analyzes the impact of channel mismatch on interference cancellation ratio (ICR), firstly. According...
To provide effective communication among the mobile users, interference has to be reduced to maximum extent. Reducing the interference plays a major role in providing effective communication among mobile users. By using smart antennas we can increase the capacity and coverage area of wireless sensor networks. By increasing the capacity and coverage area it is possible to provide line of sight communication...
Green telecommunication is becoming an important part in designing the wireless communication systems. Small Cell Network (SCN) is considered as one of the most promising techniques in the future cellular networks. In order to reduce the high power consumption caused by dense deployment of small base stations (BSs), we first propose a new decentralized precoding algorithm which aims to maximize the...
This paper considers the design of beamforming matrices for multi-cell interference alignment (IA). Different from the existing centralized algorithms for coordinated IA, the focus here is on low-complexity distributed algorithms that are easy to implement on large networks. Towards this end, the rank-minimization form of the coordinated IA problem is formulated as a general-form consensus problem,...
We propose a novel probabilistic model for the interference power distributions in a cellular network employing MIMO beamforming in mmWave spectrum. Considering both line-of-sight (LOS) and non-line-of-sight (NLOS) propagations, we use the Gamma distribution for LOS interference power, and propose a mixture of the Inverse Gaussian and Inverse Weibull distributions for the NLOS interference power....
Motivated by the observation that energy harvesting (EH) from radio-frequency (RF) signal is subject to fluctuations, multiple EH-enabled relays are employed to collaboratively enhance data communications in a device-to-device (D2D) network underlying a cellular system. Each relay is equipped with a single antenna and unable to harvest energy and transmit data simultaneously. Thus, the D2D user equipment...
This paper studies a robust beamforming optimization problem of minimizing total transmit power in a distributed manner in the presence of imperfect channel state information (CSI) in multicell interference networks. Due to the fact that worst- case is a rare occurrence in practical network, this problem is constrained to satisfying a set of signal-to-interference-plus-noise-ratio (SINR) requirements...
Abstract-Research efforts to incorporate multicast and broadcast transmission into the cellular network architecture are gaining momentum, particularly for multimedia streaming applications. Layered division multiplexing (LDM), a form of nonorthogonal multiple access (NOMA), can potentially improve unicast throughput and broadcast coverage with respect to traditional orthogonal frequency division...
The nested array, which is implemented by nonuniform antenna placement, is an effective approach to achieve O(N^2) degrees of freedom (DoF) with an antenna array of N antennas. Such DoF refers to the number of directions of incoming signals that can be resolved. With the increased number of DoF, an important application of nested array is to nullify the interference signals from multiple directions...
Millimeter-wave (mm-Wave) systems with $\mbox{hybrid digital-to-analog beamforming (D-A BF)}$ have the potential to fulfill 5G traffic demands. The capacity of mm-Wave systems is severely limited as each radio frequency (RF) transceiver chain in current base station (BS) architectures support only a particular user. In order to overcome this problem when high density of users are present, a new algorithm...
The combination of singular value decomposition (SVD)-based beamforming and filter bank multicarrier with offset quadrature amplitude modulation (FBMC/OQAM) has not been successful to date. The difficulty of this combination is that, the beamformers may change dramatically between adjacent subchannels, therefore destroy the orthogonality of FBMC/OQAM real-valued symbols, under frequency selective...
We develop a novel opportunistic beamforming scheme referred to as doubly opportunistic beamforming (DOBF), which is doubly selective in both users and beams. The sum-rate performance of the proposed scheme is investigated in less-known finite networks where the number of transmit antennas and the number of active users are finite and of the same order of magnitude in the bursty traffic model. We...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.