The MUSIC algorithm is researched in the planar antennaarray. The conventional direction of arrival (DOA) estimation method in the planar arrayantennas uses the technology of beam scanning. It needs a lot of array e...
详细信息
ISBN:
(纸本)9781479989201
The MUSIC algorithm is researched in the planar antennaarray. The conventional direction of arrival (DOA) estimation method in the planar arrayantennas uses the technology of beam scanning. It needs a lot of array element. To the finite conformal array DOA estimation, the resolution ratio will be affected by the Rayleigh limit. While, the MUSIC algorithm can fully utilize the orthogonality of noise subspace and signal subspace, it can achieve the DOA estimation through the spectrum peak search. Based on the planar arrayantenna, the Bartlett beam-forming method the CAPON minimum variance method and the MUSIC algorithm are analyzed and simulated. The simulation results show that the MUSIC algorithm has higher resolution relative to the two traditional algorithms.
The next-generation wireless technology that can fulfill such a demand, namely the fifth-generation (5G) technology, should provide 1000 times larger capacity. Moreover, sixth-generation (6G) communication, which repr...
详细信息
The next-generation wireless technology that can fulfill such a demand, namely the fifth-generation (5G) technology, should provide 1000 times larger capacity. Moreover, sixth-generation (6G) communication, which represents a significant upgrade from the fifth-generation (5G) network and is anticipated to operate from 100 GHz to 3 THz band, will be required in the years after 2030 due to newly developed data-hungry applications and the greatly expanded wireless network. To meet the ever-growing demands of wireless carriers, an efficient wireless access method that can improve wireless area throughput without expanding bandwidth or cell size is required. Radio Frequency (RF) Orbital Angular Momentum vortex waves (which is now on referred to as OAM waves) to address the concerns mentioned above have attracted much attention in recent years. Due to their orthogonality, different OAM waves of different modes can be multiplexed in the same frequency channel, which can greatly increase the channel capacity. Using the orthogonal modes, a new type of multiple access scheme known as Mode Domain Multiple Access (MDMA) can be used by multiple users using the same frequency channel without additional resources such as frequency and time. As a result, the channel capacity for the next generation wireless communication systems can be enhanced as well as the overall spectrum efficiency can be improved. This review paper begins with an overview of the next generation communication such as 5G communication technology and beyond. This paper first briefly discusses the theory of OAM waves and several methods to generate OAM waves. Various different designs have also been analyzed for their ability to generate OAM waves and discussion on several restrictions and solutions to resolve. Open concerns and development trends are discussed for possible future RF OAM antenna upgrades. This study also proposes that for next generation wireless communication employing OAM, the typically used Un
This article presents the generation of Orbital AngularMomentum(OAM)vortex waves with mode 1 using uniformcirculararray(UCA)*** different designs,namely,UCA-1(4-element arrayantenna)and UCA-2(8-element array antenn...
详细信息
This article presents the generation of Orbital AngularMomentum(OAM)vortex waves with mode 1 using uniformcirculararray(UCA)*** different designs,namely,UCA-1(4-element arrayantenna)and UCA-2(8-element arrayantenna),were designed and fabricated using FR-4 substrate to generate OAM mode 1 at 3.5 GHz(5G mid-band).The proposed antennaarrays comprised rectangular microstrip patch elements with inset fed *** elements were excited by a carefully designed feeding phase shift network to provide similar output energy at output ports with desired phase shift *** generated OAM waves were confirmed by measuring the null in the bore sight of their 2D radiation patterns,simulated phase distribution and intensity *** measurement results agree well with the simulation ***,a detailed mode purity analysis of the generated OAM waves was carried out considering different *** investigation found that the greater the number of elements,the higher the purity of the generated OAM *** with other previous works,the proposed antenna design of this paper is very simple to design and *** addition,the proposed antennas are compact in design even at lower frequency band with very wide bandwidth to meet the requirements of 5G mid-band applications.
In this paper, we present an analytical modeling framework for supporting and evaluating the impact of shadowing and beamforming on the topological connectivity of cognitive radio ad-hoc networks (CRAHNs) where primar...
详细信息
In this paper, we present an analytical modeling framework for supporting and evaluating the impact of shadowing and beamforming on the topological connectivity of cognitive radio ad-hoc networks (CRAHNs) where primary users (PUs) are equipped with omnidirectional antennas while secondary users (SUs) are equipped with directional antennas such as uniform linear array (ULA) antenna and uniformcirculararray (UCA) antenna. The main features and contributions in this paper are as follows. First, we derive a formula for calculating effective coverage area of a node in secondary network by taking the effect of path loss, antenna model, and beamforming scheme into consideration. Second, we mathematically analyze the expected number of neighbors and communication probability of a SU based on the effective coverage area of SU and the spatial-temporal existence of PU's operation. We also derive the expression of the upper bound of path connectivity between two arbitrary SUs in the networks. Third, we point out that UCA antenna is the most suitable antenna for CRAHNs. We find the optimal number of elements corresponding to each type of directional antenna at which the highest connectivity can be achieved. The validity of our analysis is verified by comparing with simulations. The results in this paper provide efficient guidelines for system designers to characterize and optimize the connectivity of CRAHNs with beamforming.
This paper investigates the impact of using directional antennas and beamforming schemes on the connectivity of cognitive radio ad hoc networks (CRAHNs). Specifically, considering that secondary users use two kinds of...
详细信息
This paper investigates the impact of using directional antennas and beamforming schemes on the connectivity of cognitive radio ad hoc networks (CRAHNs). Specifically, considering that secondary users use two kinds of directional antennas, i.e., uniform linear array (ULA) and uniformcirculararray (UCA) antennas, and two different beamforming schemes, i.e., randomized beamforming and center-directed to communicate with each other, we study the connectivity of all combination pairs of directional antennas and beamforming schemes and compare their performances to those of omnidirectional antennas. The results obtained in this paper show that, compared with omnidirectional transmission, beamforming transmission only benefits the connectivity when the density of secondary user is moderate. Moreover, the combination of UCA and randomized beamforming scheme gives the highest path connectivity in all evaluating scenarios. Finally, the number of antenna elements and degree of path loss greatly affect path connectivity in CRAHNs.
暂无评论