Reduction of Peak-to-Average Power Ratio of OFDM System Using Triangular Distribution Based Modified Companding Scheme

ABSTRACT

Orthogonal frequency division multiplexing (OFDM) is an attractive multicarrier modulation technique, which is widely introduced in the present as well as future broadband wireless communication systems due to high data rate, high spectral efficiency, and robustness to the multipath fading channel. Despite its popularity, OFDM system suffers from the critical drawback of large peak-to-average power ratio (PAPR) of the transmitted signal, which may lead to undesired spectral re-growth, poor power efficiency, and overall performance degradation. In this paper, we propose an efficient non-linear companding transform (NCT) technique for reducing the PAPR of OFDM signals. Our proposed scheme coined as triangular distribution (TR) based companding offers an improved bit error rate (BER), better design flexibility, and more degrees of freedom while reducing PAPR effectively compared to the other existing companding schemes. The PAPR reduction performance of our proposed scheme for the different modulation approaches like QPSK, 4QAM, 16QAM, 32QAM, and 64QAM is also presented here. The theoretical analysis of the proposed scheme and comparative study with the existing algorithms are presented. Simulation results demonstrate that our proposed companding scheme can substantially outperform the existing NCT techniques in terms of PAPR reduction, BER performance, and bandwidth efficiency for each of the modulation approaches under different noisy channel conditions.

KEYWORDS:

• Non-linear companding transform (NCT)
• Orthogonal frequency division multiplexing (OFDM)
• Peak-to-average power ratio (PAPR)
• Triangular distribution

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Subhankar Bhattacharjee

Subhankar Bhattacharjee received the MTech degree in electronics design and technology from Tezpur Central University, Assam, India, in 2005. He is currently working towards the PhD degree in digital signal processing at Calcutta University, A. K.Choudhury School of Information Technology, Kolkata, India. He is now an assistant professor in Electronics and Communication Engineering department in Techno India College of Technology, Kolkata, India. His current research interests include MIMO, OFDM wireless communication systems, and PAPR reduction techniques.

E-mail: [email protected]

Mahua Rakshit

Mahua Rakshit received the MTech degree in electronics and communication engineering from West Bengal University of Technology, Kolkata, West Bengal, India, in 2015. She is an independent researcher. Her research interests include OFDM wireless communication system, MIMO, PAPR reduction techniques, and cognitive radio.

E-mail: [email protected]

Sanjib Sil

Sanjib Sil received the PhD degree in engineering from Jadavpur University, Kolkata in 2011. Presently, he is a professor and principal-in-charge of the Techno India College of Technology (TICT), New Town, Kolkata, India. His research interests include design and implementation of baseband modules in VLSI circuits for broadband wireless communication system. He is an IEEE member.

E-mail: [email protected]

Amlan Chakrabarti

Amlan Chakrabarti received the MTech and PhD (Tech.) degrees from the Department of Radiophysics and Electronics, University of Calcutta, Kolkata, India. He is at present professor and director of the A. K.Choudhury School of Information Technology, University of Calcutta. He has done his doctoral research on quantum computing and related VLSI design at Indian Statistical Institute, Kolkata, 2004–2008. He was a post-doctoral fellow at the School of Engineering, Princeton University, USA during 2011–2012. He is the recipient of BOYSCAST fellowship award in the area of engineering science from the Department of Science and Technology Govt. of India in 2011, INSA Visiting faculty award in 2014 and JSPS fellowship in 2016. He has held Visiting Scientist position at the GSI Helmohltz research laboratory Germany and Department of Computer Science and Engineering at the New York State University at Buffalo, USA during September–October 2007. He has published around 100 research papers in referred journals and conferences. His research interests are: quantum computing, VLSI design, embedded system design, video and image processing algorithms, and pattern recognition.

E-mail: [email protected]