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Rendezvous and Multi-channel Hidden Terminal problems are the two well-known challenges in developing a multi-channel MAC protocol. In literature, the Control Period Based (CPB) approach is proposed to cope with the rendezvous problem. Each channel is partitioned into several beacon intervals and each of which consists of ATIM window and data window. All hosts are asked to stay in every ATIM window...
A CMOS receiver for optical wireless communication is presented. A stable feedback transimpedance amplifier (TIA) is designed adopting a current-mode amplifier as its feedforward gain element. A band-pass limiting amplifier is employed to boost the outputs of the receiver front-end. Implemented in a 0.35 um CMOS, the optical wireless receiver achieves a maximum transimpedance gain of 95.9 dBΩ. The...
A sensor network consists of a large number of sensor nodes which have sensing functions and wireless communication functions, and a single sink node which is a base station node of the sensor network. Sensor nodes sense some environmental phenomena and send data packets about the phenomena to the sink node by multi-hop communications. Generally sensor nodes are battery-driven. Therefore shortening...
In this paper, two non-ideal effects, carrier frequency offset (CFO) and IQ imbalance, are jointly compensated for an orthogonal frequency division multiplexing (OFDM) system. Based on the two identical sequences in the preamble, a LS-based method is proposed to estimate both CFO and IQ imbalance. This method has much lower complexity than the state-of-art expectation-maximization (EM) approach. Simulation...
The challenges associated with wireless vision sensor networks are low energy consumption, less bandwidth and limited processing capabilities. In order to meet these challenges different approaches are proposed. Research in wireless vision sensor networks has been focused on two different assumptions, first is sending all data to the central base station without local processing, second approach is...
Ultra-low power SRAM is a promising memory for the next-generation electronics that focus on green and power-aware computing. Unfortunately, ultra-low power SRAM encounters serious timing uncertainty. One of the major problems is that the conventional voltage-clamping circuits cannot work when the bitlines have serious with-in-die variations. The full swing, usually required on the bitline, causes...
Wireless Personal Area Networks (WPANs) are getting popular in a variety of fields such as home/office automation, e-healthcare, etc. In WPANs, most devices are considerably energy constrained, so the communication protocol should be energy efficient. The IEEE 802.15.4 is designed as a standard protocol for low power, low data rate, low complexity and short range connections in WPANs. The standard...
Since 2008, we have been developing the integrated SoC, which incorporates from the ultra high speed multi-level QAM modem to the gigabit Ethernet interface, in a bid to adapt to the millimeter wave broadband wireless system. In 2009, we developed the SoC that functions on its maximum modulation clock 200 MHz, single-carrier 16QAM, and TDD, and managed to conduct field evaluation tests as a state...
The development of a wireless handheld terminal for indoor gas concentration detection is presented in this paper. The major motivation for this work is to develop a distributed wireless measuring system suitable for metal-oxide semiconductor gas sensors, usually with a wide range resistance (e.g. 0~100 MΩ), for indoor gas concentration detection. The handheld data acquisition terminal is developed...
This paper summaries the new topics about MIMO (Multiple-input-multiple-output) channel modeling. The scenarios are focused on transportation, such as VTV (Vehicle-to-Vehicle) and high speed railway. The sparse channel and time-variant channel are discussed. Afterwards, some novel methods for MIMO channel modeling are described and challenges for each method are summarized.
The article proposes a new type of short-range wireless information transmission equipment. It is mainly composed of a transmitter and a receiver. The transmitter and the receiver all use the high integrated and high performance single chip solution. The transmitter is only composed of pure hardware. It features simple structure, stable performance and simple debugging. The receiver not only has simple...
Traditional way of manual meter reading was not only waste of human and material resources, but also very inconvenient. Especially with the emergence of a number of high residential in recent years, this traditional way of water management was obviously inefficient. Cable automatic meter reading system is very vulnerable and it needs a heavy workload of construction wiring. In this paper, based on...
To measure high-current, contacting with the wire directly is a certain danger. This article describes a pincer current transformer what the principle of electromagnetic induction be used in, using non-contact of the current measurement methods. In addition, the current strength meter site may not be the city's conditions. In this paper, CPU used in this design of instruments is made by the U.S. company...
Routing delivery is one of the key techniques in mobile ad hoc network, which involves many aspects such as topology update, routing exchange and so on. In this paper, we firstly apply routing tree to describe the complete topology of ad hoc network, and then store the information of routing tree into every node's routing table. Sparse routing tree, as a pruned tree, is used to exchange topology information,...
With the increase in population and rapid urban sprawl in the major big cities in China, traffic monitoring in the inner-suburban areas is becoming an urgent problem to be solved. This paper proposes using cellular network for inner-suburban freeway traffic monitoring. Backgrounds of cellular network and wireless location technologies are firstly introduced. Related works including simulation tests...
This paper researched on KEELOQ algorithm and presented a wireless anti-theft system based on the KEELOQ technology. The system has one central controller and no more than eight monitors. When the whole wireless anti-theft system were designed, a physical testing about one hundred days was made. The results showed that the system works stably.
In view of low level of greenhouse automatic control system in China at present, this paper introduces a agriculture greenhouse environment monitoring system based on ZigBee technology, then gives the overall design of physical structure of system, network topology and its hardware and software designed of the composed modules. The PC software develop with Visual C++6.0 and SQL Server2000 that provides...
Currently in China the level of coal mine roadway roof abscission layer monitoring is low, especially in the most coal mine the transmission and observation of the underground separation data are by manual labor or by cable transmission, there is a high cost for coal mine. This paper introduces a roof abscission layer monitoring system based on ZigBee which is adapting to environment of coal mine...
Remote monitoring system based on GPRS is a modern monitoring system which is compose of radio communication technology, signal collection and computer network technology. This article introduces a wireless coal mine monitoring system based on GPRS communications technology. This system proposed in this paper has achieved a good result in the test.
In this paper, taking mobile robot as the research object, the embedded control system is designed adopting PC/104 as host controller, which achieves the link among the expand boards, power module, motor driving module, perception modules, the HCI interface modules and so on; Wireless communication technology in mobile robots is investigated deeply, and then wireless remote control and wireless serial...
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