Yonghua Lin

ABSTRACT Wireless communication in smart grid is a typical scenario of Machine-to-Machine (M2M) communication. For a smart grid communication system, the requirements for stability, security and reliability are more strict than those for other M2M applications. Interference management is one of the key challenges to ensure the wireless system working with stability and reliability. The interferences may come from the existed SCADA (Supervisory Control and Data Acquisition) system, or some unknown devices using the same spectrum band occasionally. In this paper, we propose a novel mechanism for a WiMAX based system to manage various in-band interferences under cognitive environment, which are meaningful when there is no dedicated spectrum resource assigned for the new system or at the stage for system evolution from narrow band to broadband. We design the periodical sensing (PS) process during the normal wireless communication to obtain the realtime interference information and define the cross layer message between PHY and MAC to deliver the interference information to downlink and uplink respectively. Based on the time and frequency domain analysis for PS data, we classify received interferences into several types and execute corresponding management methods to reduce the influences caused by interferences. Through the field test in two cities, it proves that the interference management mechanism we proposed is effective.

Wordwide interoperability for microwave access (WiMAX), or the IEEE 802.16d/e standard, is a technology for broadband wireless access (BWA) with significant market potential. In this paper, we propose a base station (BS) transceiver solution for WiMAX orthogonal-frequency division-multiplexing access (OFDMA) mode. Our aim is to provide a reference design and a simulation platform for the implementation and verification of WiMAX OFDMA physical layer (PHY). The solution focus on baseband processing, and the self-loop mode can reduce the complexity of BS simulation. Algorithm for channel estimation is introduced based on the uplink symbol structure. Space-frequency block code (SFBC) is used for transmit diversity and clipping with frequency domain filtering is selected for the peak-to-average power ratio (PAPR) reduction. Simulation results show that the proposed solution can fulfill the bit-error- rate (BER) requirements of WiMAX.

We investigate the transmit diversity for orthogonal frequency division multiplexing code division multiple access (OFDM-CDMA). Diversity transmission at the base station is an effective technique to combat channel fading. Space-time (ST) coding has been proposed as coding technique to improve the system performance with additional gains. By combing the spatial transmit diversity with the space-time codes for OFDM systems it

ABSTRACT Smart Grid is an attractive topic in recent years, especially for those developing countries, such as China, who has large population and less energy resources. An extensive communication system is the essential infrastructure of the Smart Grid to ensure information exchange and resource management rapidly and efficiently. Since it will affect all areas of power grid, from generation system to transmission and distribution system, the communication system will be hybrid and involve various communication technologies, such as optical transmission, wireless techniques, advanced sensor networks, etc. In this paper, we focus the discussion on the broadband wireless access techniques used for monitoring power transmission line. We propose a hybrid wireless system based on WiFi and WiMAX to complete the dual directional communications for data collection and system controlling. The deployment capacity is analyzed and the challenges for spectrum utilization are discussed. Simulation results indicate that the system we designed can match the performance requirements when sharing spectrum with others.

Wireless baseband processing, which is character- ized by high computation complexity and high data throughput, is regarded as the most challenging issue for software radio (SR) systems. To relieve this implementation difficulty in SR systems, the multicore architecture is proposed. However, due to the lack of the universal parallel programming framework for SR systems, it is difficult to take full advantage of the multicore architecture. To fill this gap, in this paper, an efficient parallel SR framework is proposed under the Cell multicore architecture for WiMAX base station (BS). With the proposed framework, one Cell blade server (including two Cell processors) can support up to three sectors, and each sector can support 20Mbps data rate for both uplink and downlink. The system performance results verify the effectiveness of the proposed SR multicore framework. Index Terms—Software Radio, Multicore Architecture, WiMAX, Baseband Processing, Parallel Framework

The mobile Internet has seen tremendous progress due to the standardization efforts around WiMAX, LTE and beyond. There are also early trends towards adoption of software radio and a growing presence of general purpose platforms in wireless networking. Such platforms are programmer-friendly and with recent advances on multi-core and hybrid architectures, allow signal processing, network processor class packet processing, wire-speed

To enable full mechanical automation where each smart device can play multiple roles among sensor, decision maker, and action executor, it is essential to construct scrupulous connections among all devices. Machine-to-machine communications thus emerge to achieve ubiquitous communications among all devices. With the merit of providing higher-layer connections, scenarios of 3GPP have been regarded as the promising solution facilitating M2M