%0 Journal Article
%T Gaussian Pulse-Based Two-Threshold Parallel Scaling Tone Reservation for PAPR Reduction of OFDM Signals
%A Lei Guan
%A Anding Zhu
%J International Journal of Digital Multimedia Broadcasting
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/470310
%X Tone Reservation (TR) is a technique proposed to combat the high Peak-to-Average Power Ratio (PAPR) problem of Orthogonal Frequency Division Multiplexing (OFDM) signals. However conventional TR suffers from high computational cost due to the difficulties in finding an effective cancellation signal in the time domain by using only a few tones in the frequency domain. It also suffers from a high cost of hardware implementation and long handling time delay issues due to the need to conduct multiple iterations to cancel multiple high signal peaks. In this paper, we propose an efficient approach, called two-threshold parallel scaling, for implementing a previously proposed Gaussian pulse-based Tone Reservation algorithm. Compared to conventional approaches, this technique significantly reduces the hardware implementation complexity and cost, while also reducing signal processing time delay by using just two iterations. Experimental results show that the proposed technique can effectively reduce the PAPR of OFDM signals with only a very small number of reserved tones and with limited usage of hardware resources. This technique is suitable for any OFDM-based communication systems, especially for Digital Video Broadcasting (DVB) systems employing large IFFT/FFT transforms. 1. Introduction Orthogonal Frequency Division Multiplexing (OFDM) is one of the most popular modulation schemes employed in modern wireless communication systems, such as DVB (Digital Video Broadcasting), WiMAX (Worldwide Interoperability for Microwave Access), and LTE (Long Term Evolution). OFDM offers many advantages, including high spectral efficiency, supporting high data rates, and tolerance to multipath fading [1]. Unfortunately, OFDM signals often have a high Peak-to-Average Power Ratio (PAPR) due to the summation of many independent subcarrier-modulated signals with random phases. High peaks occur very rarely, but the power amplifier (PA) in the transmitter may be overdriven deep into saturation on these rare occurrences, which can result in very high instantaneous spectral regrowth that causes interferences to other users. To prevent such phenomena, the PA must be ˇ°backed-offˇ± into its linear region from the saturation point by approximately the PAPR level of the input signal, which consequently leads to very low power efficiency of the transmitter. PAPR reduction techniques are proposed to reduce the high peaks of the transmit signal to a satisfactory level before transmission, allowing the PA to be operated at a higher power level to achieve high power efficiency without
%U http://www.hindawi.com/journals/ijdmb/2011/470310/