Pooria Varahram

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Orthogonal frequency division multiplexing(OFDM) is a prominent technique for providing high Quality of service(QOS) to the users by mitigating the fading of signals and also for providing high data rates in multimedia services. But Peak to Average power ratio(PAPR) is a major technical challenge in OFDM which reduces the efficiency of RF Power amplifiers.(More)
The application of digital predistortion in base band signal is an extended method of amplifier linearization to reduce the Adjacent Channel Interference (ACI) in those systems in which a varying envelope modulation scheme like OFDM and MQAM is used. Digital baseband predistortion is a highly cost-effective way to linearize Power amplifiers (PAs), but most(More)
Partial transmit sequence (PTS) is one of the most important techniques for reducing the peak to average power ratio (PAPR) in OFDM systems. This paper presents a low complexity PTS scheme by applying a new phase sequence. Unlike the conventional PTS which needs several inverse fast Fourier transform (IFFT) operations, the proposed scheme requires half IFFT(More)
In this paper the peak to average power ratio (PAPR) reduction and digital predistortion effects in orthogonal frequency division multiplexing (OFDM) systems are investigated. By applying a predistortion technique called complex gain memory predistortion (CGMP), power amplifier works at higher power efficiency. The proposed enhanced partial transmit(More)
ABSTRAC Energy consumption in Wireless Sensor Network (WSN) is one very critical factor in its operation because of being battery powered and the need to operate continuously over a long period of time. WSN nodes are generally miniaturized that make them light and mobile and non intrusive, but this leads to have a smaller space to carry bulky power sources.(More)
Efficient RF power amplifiers used in third generation systems require linearization in order to reduce adjacent channel inter-modulation distortion, without sacrificing efficiency. Digital baseband predistortion is a highly cost-effective way to linearize power amplifiers (PAs), but most existing architectures assume that the PA has a memoryless(More)