A peak to average power ratio (PAPR) reduction method is proposed that exploits the precoding or beamforming mode in WiMAX. The method is applicable to any OFDM/A systems that implements beamforming using dedicated pilots which use the same beamforming antenna weights for both pilots and data. Beamforming performance depends on the relative phase shift between antennas, but is unaffected by a p...

High Peak to Average Power Ratio (PAPR) for OFDM system is still a demanding area and difficult issue. The radio transmitter stations for covering and getting enough transmit power in their desired area have to use High Power Amplifier (HPA). On the other hand, in order the HPA have the most output power efficiency must be designed to work close to the saturation region therefore due to the hig...

One of the most important multi-carrier transmission techniques used in the latest wireless communication arena is known as Orthogonal Frequency Division Multiplexing (OFDM). It has several characteristics such as providing greater immunity to multipath fading & impulse noise, eliminating Inter Symbol Interference (ISI) & Inter Carrier Interference (ICI) using a guard interval known as Cyclic P...

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ABSTARCTDFT spreading is one of the techniques introduced for peak to average power ratio (PAPR) reduction of OFDM systems. In this technique, the input signal with DFT is spreaded such that the PAPR is minimized but this can reduce the PAPR of OFDM signal to the level of single carrier transmission. In this paper, a DFT spreading method is proposed for the PAPR reduction of OFDM systems with s...

Although OFDM seems to be a solution to keep up with the demand of increasing data rates, it has some drawbacks. Sensitivity to high PAPR is the most significant of these drawbacks. The main objective of this paper was to investigate and document the effects of PAPR on the performance of OFDM based digital communications under different channel conditions. A step-by-step approach was adopted in...

This paper proposes a new peak-to-average power ratio (PAPR) reduction scheme for short packet communications in multiple transmit antenna environments. Instead of applying individual PAPR reduction on each antenna, a joint PAPR reduction technique is proposed. By applying a relevant unitary rotation over the transmit antennas, overall PAPR of the multiple transmit antenna system is reduced. Th...

The transmit signals in an OFDM system can have high peak values in the time domain since many subcarrier components are added via an IFFT operation. Therefore, OFDM systems are known to have a high PAPR (Peak-to-Average Power Ratio), compared with single-carrier systems. In fact, the high PAPR is one of the most detrimental aspects in the OFDM system, as it decreases the SQNR (Signal-to-Quanti...

Efficiency of Orthogonal Frequency-Division Multiplexing (OFDM) system is improved by reducing the power consumed by its transmitter and also by improving the spectral efficiency. Power usage is reduced by reducing the PAPR of OFDM system and spectral efficiency is improved by Adaptive modulation and coding schemes (AMC). In OFDM system, transmission signals can have high peak values in the tim...