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Unlimited voice services no longer command premium pricing, but are viewed as “table stakes” in a broader service offering that must now include multimedia (voice, data, video) communications with a mobility component. As a result of this shift, many service providers are trying to adopt, Long Term Evolution (LTE) network strategy to deliver this multimedia experience to their subscribers [1]. Today,...
Road transportation is one of the main sources of environmental pollution. Electrification seems like the ideal solution for reducing CO2 emissions, while maintaining all the advantages of modern means of transportation. The shift to electric vehicles needs to be accompanied by an appropriate telecommunications network, which is responsible for the reliable transmission of large volumes of information...
WiMAX technology supports to different MAC and Physical Layer parameters. The performance of TCP Linux in WiMAX network is analyzed by varying MAC layer and Physical layer parameter such as channel bandwidth, cyclic prefix, modulation coding scheme, frame duration, DL: UL ratio, propagation model, full duplex mode of data transfer and other operating parameter such as downloading traffic. These parameters...
WiMAX with an OFDM physical layer employed is sensitive to carrier frequency offset. Even though most of this offset can be compensated with the initial training sequence, there still remains a residual frequency offset due to estimation errors. In this paper, we investigate pilot-based and data-aided residual frequency offset estimators and apply them to WiMAX. To improve the pilot-based method,...
In this paper, transmission performance for downlink MU-MIMO (Multiuser Multiple-Input Multiple-Output) systems with computer simulation and field experiment are described. The downlink MU-MIMO system is constructed as a transmitter with 6 antennas and receivers with 2 antennas, and the maximum number of users(receivers) is 3. In computer simulation, MU-MIMO transmission system can be realized by...
Adaptive Modulation and Coding (AMC) is one of key technologies in 4G system. Band AMC technique enables the Orthogonal Frequency-Division Multiple Access (OFDMA) system to achieve their maximum throughput by efficient utilization of wireless channel characteristics. Band AMC with the adjacent subcarrier allocation specified in 4G system (Worldwide Interoperability for Microwave Access (WiMAX) standard)...
With the popularity of winter tourism, the winter recreation activities have been increased day by day in alpine environments. However, large numbers of people and rescuers are injured and lost in this environment due to the avalanche accidents every year. Drone-based rescue systems are envisioned as a viable solution for saving lives in this hostile environment. To this aim, a European project named...
Recently, broadband wireless communication serves as one of the most growing and developing technology in the field of telecommunications. The broadband provides multimedia services for voice, video, High Definition TV (HDTV), and games with certain Quality of Service (QoS). For these services, a high data transmission is greatly needed. Worldwide Interoperability for Microwave Access (WiMAX) Network...
WiMAX is a standard based on wireless technology that provides high throughput broadband connections over long distance. This technology can be used for a number of applications, including “last mile” broadband connections, hotspots and high-speed connectivity for business customers. The objective of this article is to propose an approach to design a network on the latest standard of WiMAX namely...
As an attempt to improve throughput of WiMAX system, the oversampled WiMAX receiver is presented in this paper. Oversampling samples each transmitted symbol more than one time. Thus, several signal sequences which contain different information about channel may be obtained at the receiver. This study presents throughput of the oversampled WiMAX system that obtained by simulation over a realistic channel...
This paper presents the capacity analysis of a threshold-based multiuser scheduling scheme in broadband OFDMA systems. Fourth-generation (4G) systems such as the WiMAX and LTE have adopted the band adaptive modulation and coding (band-AMC) subcarrier permutation mode for the grouping of the physical subcarriers into logical subchannels assigned to users by the base station (BS) schedulers. In the...
The increase in mobile data usage is pushing broad-band operators towards deploying smaller cells (femtocells) and sophisticated access technologies such as OFDMA. The expected high density of deployment and uncoordinated operations of femtocells however, make interference management both critical and extremely challenging. Femtocells have to use the same access technology as traditional macrocells...
Multicast and Broadcast Service (MBS) is transmission method that multiple BS in the same geographical area compose the MBS zone to transmit the same data to multi users simultaneously. MBS users combine MBS signals which belong to same MBS zone. Therefore, MBS has a much better SINR performance than unicast service. Despite its greater efficiency, it is difficult to enable power control consider...
This paper describes both link budget analysis and field experimental results on a mobile WiMAX system deployed in Azumino city, the city scale of which is corresponding to suburban. Firstly, in this paper, the link budget analysis is performed in order to evaluate the system performance based on propagation distance, delay spread, average BER (Bit Error Rate) under a multipath fading environment,...
Worldwide Interoperability for Microwave Access (WiMAX) is defined by the IEEE 802.16. It is an IP based, wireless broadband access technology. This technology can be implemented in 4th generation wireless technologies, for Metropolitan Area Network (MAN). The IEEE 802.16 standard includes specification for the Medium Access Control (MAC) and Physical (PHY) layers and is designed to provide broadband...
WiMAX is a Worldwide Interoperability for Microwave Access. The technology is specified by the Institute of Electrical and Electronics Engineers Inc., as the IEEE 802.16 standard that works on development of globally standardized protocols for wireless MAN and it has been commercialized under the name “WiMAX”. 802-16-2004 has often been considered the “fixed standard” or “fixed WiMAX” and 802.16-2005...
Currently evolving wireless communication systems (e.g. LTE-A, WiMAX) are based on linearly precoded MIMO OFDM and utilize adaptive modulation and coding to adjust the code rate and modulation alphabet to the current channel conditions. For this purpose the transmitter requires channel knowledge, which is provided by means of receiver feedback, utilizing the rank, precoding matrix and channel quality...
Since the IEEE 802.16 first standard was proposed in 2004 to provide broadband wireless service, the standard has not only been widely studied, but also broadly commercialized. The current IEEE 802.16-2009 standard document specifies five Quality of Service classes. As is typical with most standards, IEEE 802.16 does not require the use of a specific scheduler. In this paper, we first evaluate the...
This paper presents results from a novel OFDMA multi-cell mobile broadband system-level simulator. The tool is used to statistically characterize uplink and downlink inter-cell interference. Fully loaded interference studies cannot be performed on real-world networks until they have been fully deployed. As such, interference analysis and management must be accurately performed pre- deployment using...
Abstract - High-speed mobility has been a central issue to telecommunication in both theory and practice. Each generation of technology presents unique design and engineering challenges in products and deployments. It is especially critical to a class of upcoming 4G (4th-Generation) mobile broadband systems because of broader spectrum usage, aggressive modulation schemes, and sophisticated adaptation...
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