SLM-based OFDM system without side information for data recovery

Peak to Average Power Ratio (PAPR) has been known to be a common problem in Orthogonal Frequency Division Multiplexing (OFDM). The peak value of power signals has contributed to other problems, thus the implementation of OFDM system in many wireless applications has been growing slowly. There are many techniques being discussed to reduce the PAPR in OFDM systems where one of them is reduction through scrambling. In this paper, a technique that is based on scrambling method in order to reduce high PAPR in OFDM system is introduced. This proposed technique is called the Selective Codeword Shift (SCS). The key idea of SCS is to produce a scramble data sequence where the candidate with minimum PAPR will then be selected for transmission. This has shown an improvement in reducing PAPR as compared to original OFDM signals and the conventional Selective Mapping (SLM) technique with 29.5% improvement. This technique also has the advantage of lower computational complexity as compared to conventional SLM where no multiplication of the phase factor involved in the process and no explicit side information was needed to retrieve the transmitted data at the receiver.

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Flipping PTS-OFDM System without Side Information

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.128-129.874 ◽

2011 ◽

Vol 128-129 ◽

pp. 874-877

Author(s):

Ya Zhen Li ◽

Jing Guan ◽

Li Qun Huang ◽

Jie Zhang

Keyword(s):

Channel Estimation ◽

Frequency Response ◽

Side Information ◽

Data Rate ◽

Ofdm System ◽

Channel Frequency Response ◽

Simulation Results ◽

Ofdm Signals

In this letter, we propose a novel scheme to reduce the PAPR of OFDM signals. It combined the channel estimation in OFDM system based on comb-type pilots and Flipping PTS algorithm. At the sender we insert comb pilot independently and evenly into every partitioned sub-blocks after partition. The side information of Flipping PTS algorithm as one part of the channel frequency response is transmitted. We can achieve Flipping PTS algorithm without SI. Simulation results show that performance of the new algorithm without SI is worse than the algorithm with SI. However, it reduced PAPR, increased of the data rate.

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PAPR Reduction in MIMO-OFDM System Using SLM Without SI

Journal of Optical Communications ◽

10.1515/joc-2017-0184 ◽

2017 ◽

Vol 0 (0) ◽

Author(s):

Ashish Goel ◽

Komaldeep Sidhu

Keyword(s):

Communication Systems ◽

Side Information ◽

Data Rate ◽

Papr Reduction ◽

Ofdm System ◽

Detection Capability ◽

Key Technology ◽

Mimo Ofdm ◽

Data Signal ◽

Sufficient Reduction

AbstractMIMO-OFDM is a key technology being widely used these days for 4 G communication systems but its main drawback is high PAPR. Selected mapping is commonly used approach for PAPR reduction but in SLM there is requirement of side information (SI) to be sent along with the input data signal and leading to the loss in data rate and increased complexity. In this article, we have come up with a technique for PAPR reduction in which there is no requirement of transmission of side information and therefore preserves the data rate and also provides sufficient reduction in the PAPR. In this technique, SI embedding is performed in the form of subcarrier location (index) by increasing its power. The simulation results demonstrate that the scheme which has been proposed provides the favorable response in terms of bit error rate (BER), PAPR reduction and SI detection capability.

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