Mitigating the Clipping Noise by Using the Oversampling Scheme in OFDM Systems

In an Orthogonal Frequency Division Multiplexing (OFDM) systems, the Peak to Average power Ratio (PAR) is high. The clipping signal scheme is a useful and simple method to reduce the PAR. However, it introduces additional noise that degrades the systems performance. We propose an oversampling scheme to deal with the received signal in order to reduce the clipping noise by using Finite Impulse Response (FIR) filter. Coefficients of filter are obtained by correlation function of the received signal and the oversampling information at receiver. The performance of the proposed technique is evaluated for frequency selective channel. Results show that the proposed scheme can mitigate the clipping noise significantly for OFDM systems and in order to maintain the system's capacity, the clipping ratio should be larger than 2.5.





References:
[1] S.H. Muller and J.B. Huber, "OFDM with reduced peak-to-average power
ratio by optimum combination of partial transmit sequences," Electronics
Letters, 27th Feb. 1997,Vol.33, No. 5, pp.368-369.
[2] Yong Hwan You, Won-Gi Jeon and Jong-Ho Paik, "Low-complexity PAR
reduction schemes using SLM and PTS approaches for OFDM-CDMA
signals," IEEE Trans. on Consumer Electronics, Vol.49, No.2, May,2003.
[3] Chintha Tellambura, "Improved Phase Factor Computation for the PAR
Reduction of an OFDM Signal Using PTS," IEEE Communications
Letters, Vol. 5, No. 4, April, 2001,pp.135-137.
[4] Marco Breiling, Stefan H. M├╝ller-Weinfurtner, and Johannes B. Huber,
"SLM Peak-Power Reduction Without Explicit Side Information," IEEE
Communications Letters, Vol. 5, No. 6, June 2001, pp.239-241.
[5] A.D.S.Jayalath and C.Tellambura, "A blind SLM receiver for
PAR-reduced OFDM," Vehicular Technology Conference, 2002.
Proceedings. VTC 2002-Fall. 2002 IEEE 56th , Vol.1 , 24-28 Sept. 2002,
pp.219 - 222.
[6] P.VAN. Eetvlt, G. Wade and M. Tomlinson, "peak to average power
reduction for OFDM schemes by selective scrambling," Electronics
Letters, 10th Feb. 1996, Vol.32, No. 21, pp.1963-1964.
[7] James A. Davis and Jonathan Jedwab, "Peak-to-mean power control in
OFDM, Golay complementary sequences and Reed-Muller codes," ISIT
1998, Cambridge, USA, August 16-21 p.190.
[8] Victor P.Gil Jimenez, "Study and implementation of complementary
Golay sequences for PAR reduction in OFDM signals," IEEE
MELECON 2002, May 7-9, 2002, Cairo, EGYPT, PP.198-203.
[9] J.A. Davis and J. Jadwab, "Peak-to-mean power control and error
correction for OFDM transmission using Golay sequences and
Reed-Muller codes," Electronics Letters, 13th Feb. 1997, Vol.33, No. 4,
pp.267-268.
[10] Brian Scott Krongold and Douglas L. Jones, "PAR Reduction in OFDM
via Active Constellation Extension," IEEE Trans. on Broadcasting, VOL.
49, NO. 3, Sep. 2003, pp.258-269.
[11] Henry Kwok and Douglas Jones, "PAR Reduction via Constellation
Shaping," ISIT2000, Sorrento, Italy, June 25-30, 2000, p.166.
[12] Dukhyun Kim and Gordon L. Stuber, "Clipping Noise Mitigation for
OFDM by Decision-Aided Reconstruction," IEEE Communications
Letters, Vol. 3, No. 1, Jan. 1999, pp.4-6.
[13] Xia Lei, Youxi Tang, Shaoqian Li, "A Minimum Clipping Power Loss
Scheme for Mitigating the Clipping Noise in OFDM," GLOBECOM
2003, p.6-9.
[14] Hidekei Ochiai and Hideki Imai, "Channel Capacity of Clipped OFDM
SYSTEMS," ISIT 2000, Sorrento, Italy, June 25-30, 2000, p.219.
[15] Hideki Ochiai and Hideki Imai, "Performance Analysis of Deliberately
Clipped OFDM Signals," IEEE TRANSACTIONS ON
COMMUNICATIONS, VOL. 50, NO. 1, JANUARY 2002, pp.89-101.