In this paper,we propose a Multi-token Sector Antenna Neighbor Discovery(M-SAND)protocol to enhance the efficiency of neighbor discovery in asynchronous directional ad hoc networks.The central concept of our work invo...In this paper,we propose a Multi-token Sector Antenna Neighbor Discovery(M-SAND)protocol to enhance the efficiency of neighbor discovery in asynchronous directional ad hoc networks.The central concept of our work involves maintaining multiple tokens across the network.To prevent mutual interference among multi-token holders,we introduce the time and space non-interference theorems.Furthermore,we propose a master-slave strategy between tokens.When the master token holder(MTH)performs the neighbor discovery,it decides which 1-hop neighbor is the next MTH and which 2-hop neighbors can be the new slave token holders(STHs).Using this approach,the MTH and multiple STHs can simultaneously discover their neighbors without causing interference with each other.Building on this foundation,we provide a comprehensive procedure for the M-SAND protocol.We also conduct theoretical analyses on the maximum number of STHs and the lower bound of multi-token generation probability.Finally,simulation results demonstrate the time efficiency of the M-SAND protocol.When compared to the QSAND protocol,which uses only one token,the total neighbor discovery time is reduced by 28% when 6beams and 112 nodes are employed.展开更多
The propose of this paper is to design the circularly polarized antenna for mobile base station, using a curved strip dipole associated with U-shaped reflector and multi-layer metallic rod elec-tromagnetic band gap (E...The propose of this paper is to design the circularly polarized antenna for mobile base station, using a curved strip dipole associated with U-shaped reflector and multi-layer metallic rod elec-tromagnetic band gap (EBG). It can be used to simplify the single feed system of an antenna. The advantages of this proposed antenna are easy fabrication and installation, high gain and light weight. Moreover, it provides a sectoral radiation pattern, a main beam having a narrow beam width in the vertical direction and wider beamwidth in the horizontal direction, which are appro-priate for mobile phone base station. The half-power beam in the H-plane and E-plane are 60 and 14.4 degrees, respectively. The antenna is designed and analyzed by using a computer simulation technology (CST). In addition, S11, axial ratio, radiation pattern and gain are displayed. The designed technique could be confirmed by a measurement resulting from prototype antenna corresponding to simulation results. The proposed antenna has a bandwidth covering the frequency range of 1870 - 2170 MHz, and the gain of the antenna increases up to 15.11 dBi.展开更多
A kind of novel multi-frequency monopole antenna with sector-nested fractal is proposed and designed, which is nested with a series of similar circular sector elements. By means of the trapeziform ground plane with th...A kind of novel multi-frequency monopole antenna with sector-nested fractal is proposed and designed, which is nested with a series of similar circular sector elements. By means of the trapeziform ground plane with the tapered CPW (coplanar waveguide) feeder in the middle, the antenna’s radiation performance is greatly improved. The antennas can synchronously operate in three frequencies, covering the working frequency bands of WLAN/WiMAX, 2.44 GHz/3.5 GHz/5.2 GHz - 5.8 GHz. The pattern and impedance measurements of antenna show a good performance over the WLAN/WiMAX band;it possesses a near omni-directional characteristic and good radiation efficiency. Moreover, the antenna is miniature and its design idea can be easily applied into other types of nested structure, the features of which make the proposed antenna have a promising application in other fields.展开更多
Recently, there has been much focus on mobile sensor networks, and we have even seen the development of small-profile sensing devices that are able to control their own movement. Although it has been shown that mobili...Recently, there has been much focus on mobile sensor networks, and we have even seen the development of small-profile sensing devices that are able to control their own movement. Although it has been shown that mobility alleviates several issues relating to sensor network coverage and connectivity, many challenges remain. Among these, the need for position estimation is perhaps the most important. It is too expensive to include a GPS receiver with every sensor node. Hence, localization schemes for sensor networks typically use a small number of seed nodes that know their location and protocols whereby other sensor nodes estimate their location from the messages they receive. In this paper, we propose a new technique to localize mobile sensor nodes using sectorized antenna. We consider that both sensor nodes and seeds are mobile, and argue that mobility can be exploited to improve the accuracy and precision of localization. It is tested extensively in a simulation environment and compared with other existing methods. The results of our experiments clearly indicate that our proposed approach can achieve a high accuracy without need of high density of seeds.展开更多
The circular sector patch antenna is studied in C-band (4 GHz - 8 GHz). In this paper, we present steps of designing the circular sector antenna then a comparison with a rectangular antenna in literature. High Frequen...The circular sector patch antenna is studied in C-band (4 GHz - 8 GHz). In this paper, we present steps of designing the circular sector antenna then a comparison with a rectangular antenna in literature. High Frequency Structure Simulator (HFSS) software is used to compute the gain, axial ratio, radiation pattern, and return loss S11 of proposed antenna. Based on the designed patch antenna, many phased arrays will be simulated using HFSS. The impact of distance between element, number of element and phase will be checked. Obtained results are analyzed and compared with literature.展开更多
基金supported in part by the National Natural Science Foundations of CHINA(Grant No.61771392,No.61771390,No.61871322 and No.61501373)Science and Technology on Avionics Integration Laboratory and the Aeronautical Science Foundation of China(Grant No.201955053002 and No.20185553035)。
文摘In this paper,we propose a Multi-token Sector Antenna Neighbor Discovery(M-SAND)protocol to enhance the efficiency of neighbor discovery in asynchronous directional ad hoc networks.The central concept of our work involves maintaining multiple tokens across the network.To prevent mutual interference among multi-token holders,we introduce the time and space non-interference theorems.Furthermore,we propose a master-slave strategy between tokens.When the master token holder(MTH)performs the neighbor discovery,it decides which 1-hop neighbor is the next MTH and which 2-hop neighbors can be the new slave token holders(STHs).Using this approach,the MTH and multiple STHs can simultaneously discover their neighbors without causing interference with each other.Building on this foundation,we provide a comprehensive procedure for the M-SAND protocol.We also conduct theoretical analyses on the maximum number of STHs and the lower bound of multi-token generation probability.Finally,simulation results demonstrate the time efficiency of the M-SAND protocol.When compared to the QSAND protocol,which uses only one token,the total neighbor discovery time is reduced by 28% when 6beams and 112 nodes are employed.
文摘The propose of this paper is to design the circularly polarized antenna for mobile base station, using a curved strip dipole associated with U-shaped reflector and multi-layer metallic rod elec-tromagnetic band gap (EBG). It can be used to simplify the single feed system of an antenna. The advantages of this proposed antenna are easy fabrication and installation, high gain and light weight. Moreover, it provides a sectoral radiation pattern, a main beam having a narrow beam width in the vertical direction and wider beamwidth in the horizontal direction, which are appro-priate for mobile phone base station. The half-power beam in the H-plane and E-plane are 60 and 14.4 degrees, respectively. The antenna is designed and analyzed by using a computer simulation technology (CST). In addition, S11, axial ratio, radiation pattern and gain are displayed. The designed technique could be confirmed by a measurement resulting from prototype antenna corresponding to simulation results. The proposed antenna has a bandwidth covering the frequency range of 1870 - 2170 MHz, and the gain of the antenna increases up to 15.11 dBi.
文摘A kind of novel multi-frequency monopole antenna with sector-nested fractal is proposed and designed, which is nested with a series of similar circular sector elements. By means of the trapeziform ground plane with the tapered CPW (coplanar waveguide) feeder in the middle, the antenna’s radiation performance is greatly improved. The antennas can synchronously operate in three frequencies, covering the working frequency bands of WLAN/WiMAX, 2.44 GHz/3.5 GHz/5.2 GHz - 5.8 GHz. The pattern and impedance measurements of antenna show a good performance over the WLAN/WiMAX band;it possesses a near omni-directional characteristic and good radiation efficiency. Moreover, the antenna is miniature and its design idea can be easily applied into other types of nested structure, the features of which make the proposed antenna have a promising application in other fields.
文摘Recently, there has been much focus on mobile sensor networks, and we have even seen the development of small-profile sensing devices that are able to control their own movement. Although it has been shown that mobility alleviates several issues relating to sensor network coverage and connectivity, many challenges remain. Among these, the need for position estimation is perhaps the most important. It is too expensive to include a GPS receiver with every sensor node. Hence, localization schemes for sensor networks typically use a small number of seed nodes that know their location and protocols whereby other sensor nodes estimate their location from the messages they receive. In this paper, we propose a new technique to localize mobile sensor nodes using sectorized antenna. We consider that both sensor nodes and seeds are mobile, and argue that mobility can be exploited to improve the accuracy and precision of localization. It is tested extensively in a simulation environment and compared with other existing methods. The results of our experiments clearly indicate that our proposed approach can achieve a high accuracy without need of high density of seeds.
文摘The circular sector patch antenna is studied in C-band (4 GHz - 8 GHz). In this paper, we present steps of designing the circular sector antenna then a comparison with a rectangular antenna in literature. High Frequency Structure Simulator (HFSS) software is used to compute the gain, axial ratio, radiation pattern, and return loss S11 of proposed antenna. Based on the designed patch antenna, many phased arrays will be simulated using HFSS. The impact of distance between element, number of element and phase will be checked. Obtained results are analyzed and compared with literature.
