beamformingantennas(波束形成天线).ppt

Beamforming Antennas for  Wireless Communications Outline Infrastructure mode An indoor WLAN design Ad hoc mode Ad hoc WLAN for rural area Applications of beamforming technology Phased array RADAR Phased array spike sorting Patterns, beamwidth Gain Beamformers vs. omnidirectional antennas Beamformers vs. omnidirectional antennas Beamformers vs. omnidirectional antennas DOA estimation Beamforming Basic phased array configurations Basic phased array configurations Smart antenna systems Smart antenna systems Smart antenna systems Smart antenna system Polarization Super CART 3-loop 2-loop Vector antennas vs. spatial array antennas Vector antennas vs. spatial array antennas Vector antennas vs. spatial array antennas Vector antennas Vs. phased array antennas Low profile antennas with polarization diversity Packet switching Packet switching: 3 beam system An indoor WLAN design An indoor WLAN design An indoor WLAN design Beamforming antennas in ad hoc networks Beamforming antennas in ad hoc networks Beamforming antennas in ad hoc networks Medium Access Control Protocol(CSMA/CA) Channel access Channel access Neighbor discovery Ad hoc WLAN for rural area Conclusion Beamforming antenna systems improve wireless network performance -increase system capacity -improve signal quality -suppress interference and noise -save power Beamforming antennas improve infrastructure networks performance. They may improve ad hoc networks performance. New MAC protocol standards are needed. Vector antennas may replace spatial arrays to further improve beamforming performance Mean pathloss with smin: Path loss model: The coverage ranges are:r=36m,29m,23m and 18m for date rate at 1Mbps, 2Mbps, 5.5Mbps and 11Mbps respectively Allowable pathloss: Case 1: user is on the 3rd floor: 3 concrete walls, 3 soft partitions The coverage ranges are: r=176m,140m,111m and 88m for date rate at 1Mbps, 2Mbps, 5.5Mbps and 11Mbps respectively . Case 2: user is in the basement : 3 floors