Orthogonal frequency division multiplexing is one of the modulation techniques used as a high speed transmission technology with good interference reduction properties. High peak to average power ratio (PAPR) in transmitted signal is one of the major disadvantages of OFDM technique. We propose a optimal search algorithm called Partial Transmit Sequences (OSA-PTS) is used to reduce peak to avera...

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Orthogonal Frequency Division Multiplexing (OFDM) is a well-known modulation technique for transmission of large amount of digital data with high data rate in both wired and wireless communication systems. High peak-to-average power ratio (PAPR) is the main problem of OFDM system which can be improved by using single carrier frequency division multiple access (SC-FDMA) technique. A new scheme u...

Orthogonal Frequency Division Multiplexing (OFDM) is a digital transmission method developed to meet the increasing demand for higher data rates in communications which can be used in both wired and wireless environments. Coding, Phase rotation and Clipping are among many PAPR reduction schemes that have been proposed to overcome this problem. In this paper, we are analysed on three different P...

The ability to model the temporal dimension is essential to many applications. Furthermore, the rate of increase in database size and response time requirements has outpaced advancements in processor and mass storage technology, leading to the need for parallel temporal database management systems. In this paper, we introduce a variety of parallel temporal aggregation algorithms for a sharednot...

Data <span>transmission in orthogonal frequency division multiplexing (OFDM) system needs source and channel coding, the transmitted data suffers from bad effect of large peak to average power ratio (PAPR). Source code codes can be joined using different codes. Variable length error correcting (VLEC) is one these VLEC used mat lab simulation for image transmission OFDM system, compared fi...

The high peak-to-average power ratio (PAPR) of the transmitted signal is a major drawback of multicarrier transmission such as orthogonal frequency-division multiplexing OFDM. A plethora of PAPR reduction techniques has been reported in the literature. Some of the techniques modify the phase and/or amplitude of symbols in the original symbol alphabet (SA) such as selected mapping and partial tr...

Introduction: The combination of multiple-antenna techniques, often collectively referred to as multiple-input multiple-output (MIMO), with the multicarrier transmission scheme orthogonal frequency division multiplexing (OFDM) is a very promising solution for next generation broadband wireless systems since both approaches exploit the wireless multipath channel. One of the most popular MIMO tec...

The IRAF† CCD reduction package, ccdred, provides tools for the easy and efficient reduction of CCD images. The standard reduction operations are replacement of bad pixels, subtraction of an overscan or prescan bias, subtraction of a zero level image, subtraction of a dark count image, division by a flat field calibration image, division by an illumination correction, subtraction of a fringe im...