Abstract: Non-linear programming has been extensively used in wireless telecommunication systems design. PAPR reduction is implemented in the handheld devices and low complexity is a major objective. High PAPR is one of the major disadvantages of OFDM system which is resulted from large envelope fluctuation of the signal. Our proposed technique to reduce the PAPR is based on constellation shaping that starts with a larger constellation of points, and then the points with higher energy are removed. The constellation shaping algorithm is combined with peak reduction, with extra abilities defined to reduce the signal peak. This method, called MMSE-Threshold, has a significant improvement in PAPR reduction with low computational complexity. The peak reduction formulated into a quadratic minimization problem is subsequently optimized by the semi-definite programming algorithm, and the simulation results show that the PAPR of semi-definite programming algorithm (SDPA) has noticeable improvement over M

• Publication Date: 09-Jul-2012
• DOI: 10.15224/978-981-07-2950-9-9566
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Abstract: This paper focuses on social responsibility of governments in face with natural disasters, investment, control and decreasing Human and material looses of these disasters that its results will affect natural disaster management. In this paper disaster and disaster management are defined and then the infrastructure damage of different disasters is explained with some examples. A comparison is performed between the disaster management in a developing country and a developed country (Iran and Japan) based on their ability in services for managing disasters that shows the difference in looses and deaths.

• Publication Date: 09-Jul-2012
• DOI: 10.15224/978-981-07-2950-9-9606
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