Although the wireless broadband access system is developing rapidly, its development is limited due to some disadvantages , such as small capacity of bandwidth and small coverage . The Wireless Mesh Network (WMN) is o...Although the wireless broadband access system is developing rapidly, its development is limited due to some disadvantages , such as small capacity of bandwidth and small coverage . The Wireless Mesh Network (WMN) is one of the important technologies for 'last mile 'broadband wireless access . The WMN can integrate with multiple wireless systems , such as Wireless Local Area Network (WLAN), Wireless Personal Area Network (WPAN), and Wireless Metropolitan Area Network (WMAN), to improve the performance of the wireless network and enlarge the coverage range . With the wide applications of the WMN, the IEEE 802 standard group is devoted to promoting the development of the WMN technology and establishing the related technical standards . At present, WMN standards have appeared in IEEE 802.11s , 802.15, 802.16, and 802.20.展开更多
The Wireless Gigabit Alliance （WiGig） and I EEE 802.11 ad are developing a multigigabit wireless personal and local area network （WPAN/ WLAN） specification in the 60 GHz millimeter wave band. Chipset manufacturers...The Wireless Gigabit Alliance （WiGig） and I EEE 802.11 ad are developing a multigigabit wireless personal and local area network （WPAN/ WLAN） specification in the 60 GHz millimeter wave band. Chipset manufacturers, original equipment manufacturers （OEMs）, and telecom companies are also assisting in this development. 60 GHz millimeter wave transmission will scale the speed of WLANs and WPANs to 6.75 Gbit/s over distances less than 10 meters. This technology is the first of its kind and will eliminate the need for cable around personal computers, docking stations, and other consumer electronic devices. High-definition multimedia interface （HDMI）, display port, USB 3.0, and peripheral component interconnect express （PCle） 3.0 cables will all be eliminated. Fast downloads and uploads, wireless sync, and multi-gigabit-per-second WLANs will be possible over shorter distances. 60 GHz millimeter wave supports fast session transfer （FST） protocol, which makes it backward compatible with 5 GHz or 2.4 GHz WLAN so that end users experience the same range as in today＇ s WLANs. IEEE 802.1 lad specifies the physical （PHY） sublayer and medium access control （MAC） sublayer of the protocol stack. The MAC protocol is based on time-division multiple access （TDMA）, and the PHY layer uses single carrier （SC） and orthogonal frequency division multiplexing （OFDM） to simultaneously enable low-power, high-performance applications.展开更多
OFDM has been widely adopted in several communication systems. However, OFDM systems are very sensitive to the phase noise, which causes the CPE （common phase error） and ICI （inter-carrier interference）, and thus ...OFDM has been widely adopted in several communication systems. However, OFDM systems are very sensitive to the phase noise, which causes the CPE （common phase error） and ICI （inter-carrier interference）, and thus degrades the system performance significantly. Based on the IEEE 802.11a standard, a simplified iterative phase noise mitigation algorithm is proposed. The proposed algorithm has very low complexity, and requires no additional pilot information. The simulation result shows that good BER performance can be achieved through several few times of iteration.展开更多
This paper presents a CMOS G;-C complex filter for a low-IF receiver of the IEEE802.15.4 standard.A pseudo differential OTA with reconfigurable common mode feedback and common mode feed-forward is proposed as well as ...This paper presents a CMOS G;-C complex filter for a low-IF receiver of the IEEE802.15.4 standard.A pseudo differential OTA with reconfigurable common mode feedback and common mode feed-forward is proposed as well as the frequency tuning method based on a relaxation oscillator.A detailed analysis of non-ideality of the OTA and the frequency tuning method is elaborated.The analysis and measurement results have shown that the center frequency of the complex filter could be tuned accurately.The chip was fabricated in a standard 0.35μm CMOS process,with a single 3.3 V power supply.The filter consumes 2.1 mA current,has a measured in-band group delay ripple of less than 0.16μs and an IRR larger than 28 dB at 2 MHz apart,which could meet the requirements of the IEEE802.15.4 standard.展开更多
Resilient Packet Ring （RPR）, or the Standard IEEE 802.17, is a new IP-based network technology proposed to replace SONET/SDH in metropolitan area networks. RPR is well-adapted to handle multimedia traffic and is eff...Resilient Packet Ring （RPR）, or the Standard IEEE 802.17, is a new IP-based network technology proposed to replace SONET/SDH in metropolitan area networks. RPR is well-adapted to handle multimedia traffic and is efficient. However, when RPR networks are bridged, inter-ring packets, or packets with the destination on a remote RPR network other than on the source network, are flooded on the source and the destination networks, and also on the path of the intermediate networks between the source and the destination networks. This decreases the available bandwidth for other traffic in those networks and is inefficient. As a result, we propose two solutions based on topology discovery, global topology discovery （GTD） and enhanced topology discovery （ETD）, that prevent the flooding of inter-ring packets. GTD enables the bridges to determine the next-hop bridge for each destination. ETD enables the source node to determine a default ringlet, so that packets reach the next-hop bridge without flooding the source network. The proposed solutions were analyzed and the overhead bandwidth and stabilization time were shown to be bounded. Simulations performed showed that the proposed solutions successfully avoid flooding and achieve optimal efficiency in the intermediate and destination networks, and in the source networks with one bridge.展开更多
文摘Although the wireless broadband access system is developing rapidly, its development is limited due to some disadvantages , such as small capacity of bandwidth and small coverage . The Wireless Mesh Network (WMN) is one of the important technologies for 'last mile 'broadband wireless access . The WMN can integrate with multiple wireless systems , such as Wireless Local Area Network (WLAN), Wireless Personal Area Network (WPAN), and Wireless Metropolitan Area Network (WMAN), to improve the performance of the wireless network and enlarge the coverage range . With the wide applications of the WMN, the IEEE 802 standard group is devoted to promoting the development of the WMN technology and establishing the related technical standards . At present, WMN standards have appeared in IEEE 802.11s , 802.15, 802.16, and 802.20.
文摘The Wireless Gigabit Alliance （WiGig） and I EEE 802.11 ad are developing a multigigabit wireless personal and local area network （WPAN/ WLAN） specification in the 60 GHz millimeter wave band. Chipset manufacturers, original equipment manufacturers （OEMs）, and telecom companies are also assisting in this development. 60 GHz millimeter wave transmission will scale the speed of WLANs and WPANs to 6.75 Gbit/s over distances less than 10 meters. This technology is the first of its kind and will eliminate the need for cable around personal computers, docking stations, and other consumer electronic devices. High-definition multimedia interface （HDMI）, display port, USB 3.0, and peripheral component interconnect express （PCle） 3.0 cables will all be eliminated. Fast downloads and uploads, wireless sync, and multi-gigabit-per-second WLANs will be possible over shorter distances. 60 GHz millimeter wave supports fast session transfer （FST） protocol, which makes it backward compatible with 5 GHz or 2.4 GHz WLAN so that end users experience the same range as in today＇ s WLANs. IEEE 802.1 lad specifies the physical （PHY） sublayer and medium access control （MAC） sublayer of the protocol stack. The MAC protocol is based on time-division multiple access （TDMA）, and the PHY layer uses single carrier （SC） and orthogonal frequency division multiplexing （OFDM） to simultaneously enable low-power, high-performance applications.
文摘OFDM has been widely adopted in several communication systems. However, OFDM systems are very sensitive to the phase noise, which causes the CPE （common phase error） and ICI （inter-carrier interference）, and thus degrades the system performance significantly. Based on the IEEE 802.11a standard, a simplified iterative phase noise mitigation algorithm is proposed. The proposed algorithm has very low complexity, and requires no additional pilot information. The simulation result shows that good BER performance can be achieved through several few times of iteration.
基金Project supported by the National High Technology Research and Development Program of China(No.2008AA010701)
文摘This paper presents a CMOS G;-C complex filter for a low-IF receiver of the IEEE802.15.4 standard.A pseudo differential OTA with reconfigurable common mode feedback and common mode feed-forward is proposed as well as the frequency tuning method based on a relaxation oscillator.A detailed analysis of non-ideality of the OTA and the frequency tuning method is elaborated.The analysis and measurement results have shown that the center frequency of the complex filter could be tuned accurately.The chip was fabricated in a standard 0.35μm CMOS process,with a single 3.3 V power supply.The filter consumes 2.1 mA current,has a measured in-band group delay ripple of less than 0.16μs and an IRR larger than 28 dB at 2 MHz apart,which could meet the requirements of the IEEE802.15.4 standard.
文摘Resilient Packet Ring （RPR）, or the Standard IEEE 802.17, is a new IP-based network technology proposed to replace SONET/SDH in metropolitan area networks. RPR is well-adapted to handle multimedia traffic and is efficient. However, when RPR networks are bridged, inter-ring packets, or packets with the destination on a remote RPR network other than on the source network, are flooded on the source and the destination networks, and also on the path of the intermediate networks between the source and the destination networks. This decreases the available bandwidth for other traffic in those networks and is inefficient. As a result, we propose two solutions based on topology discovery, global topology discovery （GTD） and enhanced topology discovery （ETD）, that prevent the flooding of inter-ring packets. GTD enables the bridges to determine the next-hop bridge for each destination. ETD enables the source node to determine a default ringlet, so that packets reach the next-hop bridge without flooding the source network. The proposed solutions were analyzed and the overhead bandwidth and stabilization time were shown to be bounded. Simulations performed showed that the proposed solutions successfully avoid flooding and achieve optimal efficiency in the intermediate and destination networks, and in the source networks with one bridge.
