scholarly journals Implementation of a Smart Antenna Base Station for Mobile WiMAX Based on OFDMA

Author(s):  
Seungheon Hyeon ◽  
Changhoon Lee ◽  
Chang-eui Shin ◽  
Seungwon Choi
Author(s):  
A. Kuchar ◽  
M. Taferner ◽  
M. Tangemann ◽  
C. Hoek ◽  
W. Rauscher ◽  
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Keyword(s):  

2014 ◽  
Vol 10 (2) ◽  
pp. 173-196 ◽  
Author(s):  
M. Louta ◽  
P. Sarigiannidis ◽  
S. Misra ◽  
P. Nicopolitidis ◽  
G. Papadimitriou

WiMAX (Worldwide Interoperability for Microwave Access) constitutes a candidate networking technology towards the 4G vision realization. By adopting the Orthogonal Frequency Division Multiple Access (OFDMA) technique, the latest IEEE 802.16x amendments manage to provide QoS-aware access services with full mobility support. A number of interesting scheduling and mapping schemes have been proposed in research literature. However, they neglect a considerable asset of the OFDMA-based wireless systems: the dynamic adjustment of the downlink-to-uplink width ratio. In order to fully exploit the supported mobile WiMAX features, we design, develop, and evaluate a rigorous adaptive model, which inherits its main aspects from the reinforcement learning field. The model proposed endeavours to efficiently determine the downlink-to-uplinkwidth ratio, on a frame-by-frame basis, taking into account both the downlink and uplink traffic in the Base Station (BS). Extensive evaluation results indicate that the model proposed succeeds in providing quite accurate estimations, keeping the average error rate below 15% with respect to the optimal sub-frame configurations. Additionally, it presents improved performance compared to other learning methods (e.g., learning automata) and notable improvements compared to static schemes that maintain a fixed predefined ratio in terms of service ratio and resource utilization.


2015 ◽  
Author(s):  
M. K. Salman ◽  
R. B. Ahmad ◽  
Ziad G. Ali ◽  
Jaafar A. Aldhaibani ◽  
Rashid A. Fayadh

2013 ◽  
Vol 760-762 ◽  
pp. 954-958
Author(s):  
Run Jie Liu ◽  
Dan Li Kou

With the rapid development of China's TD-SCDMA system, how to qualitative and quantitative to judge intelligent antenna electromagnetic radiation pollution is a problem to be solved. Due to the special working principle of smart antenna, the second generation communication system spectrometer and field intensity meter measurement method is a complicated and difficult to operate. This paper introduces a design suitable for TD smart antenna measurement system: this system can realize in single user or multiple users at the same time and the TD base station set up calls link of multi-point synchronous signal intensity measurement. The measurement results of our system are very close to the measurement results of spectrometer field intensitys and can reasonable reflect TD stations around the extent of the electromagnetic radiation. This method of our system is easy, cheap and maneuverable


2016 ◽  
Vol 78 (5-8) ◽  
Author(s):  
Norsuzila Ya'acob ◽  
Akmarya Syukhairilnisah Mohd Akhir ◽  
Fazida Adlan ◽  
Azita Laily Yusof ◽  
Mohd Saufi Nasro Ali ◽  
...  

The growing demand for mobile internet and wireless multimedia applications has motivated the development of broadband wireless-access technologies in recent years. There are several issues that could impact the base station handover as a serious problem in the mobile communication system. In hard handover, a short time break known as handover interruption decreases the quality-of-services (QoS) due to connection between mobile subscriber station (MS) and serving base station (BS) is closed and ranging hand initiation to establish new connection. Prolonged time of request and response due to number of neighbours to scan will cause delay in handover process. This research proposed performance analysis of WiMAX/IEEE 802.16 with mobility supported to scan the channels provided by the mobile station. The proposed strategy required the mobile station for operation with a scan that can be used to reduce the time when trying to establish a network connection or do between neighboring base station handover. A second type is the fast handover that is proposed to reduce the unnecessary surrender to six different access modes. The mobile WiMAX air interface utilizes orthogonal frequency division multiple access (OFDMA) as the preferred multiple-access method in the downlink (DL) and uplink (UL) for improved multipath performance and bandwidth scalability. All simulations are run using MATLAB software to develop a new Overlay Scanning Mechanism (OSMA) algorithm. OSMA mainly focus on when to perform a scan to estimate future needs. Simulation results are expected to show WiMAX coverage by using real world data to detect movement and show that there are strategies that reduce the time required for scanning operations significantly.


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