PAPR reduction in mobile WiMAX: A new ZCMT precoded random interleaved OFDMA system

Abstract

Mobile WiMAX (worldwide interoperability for microwave access) air interface adopts orthogonal frequency division multiple access (OFDMA) as multiple access technique for its uplink (UL) and downlink (DL) to improve the multipath performance. All OFDMA based networks, like mobile WiMAX, experience the problem of high peak-to-average power ratio (PAPR). The high PAPR increases the complexity of analog-to-digital (A/D) and digital-to-analog (D/A) convertors, and also reduces the efficiency of RF high-power-amplifier (HPA). In this work, a new zadoff-chu matrix transform (ZCMT) precoding based random interleaved orthogonal frequency division multiple access (OFDMA) system was proposed for PAPR reduction in mobile WiMAX system. The system is based on precoding the constellation symbols with the ZCMT precoder before subcarrier mapping. The PAPR of proposed system is analyzed with the root-raised-cosine (RRC) pulse shaping to keep out of band radiation low and meet the transmission spectrum mask requirement. Simulation results show that the proposed system has better PAPR gain than the hadamard transform (WHT) precoded random interleaved OFDMA systems and the conventional random interleaved OFDMA systems. Symbol-errorrate (SER) performance of the system is also better than the conventional random interleaved OFDMA systems and the random interleaved OFDMA systems with WHT. The good improvement in PAPR significantly reduces the cost and the complexity of the transmitter.

Keywords

peak to average power ratio / orthogonal frequency division multiple access / zadoff-chu matrix transform / mobile WiMAX / root-raised-cosine pulse shaping

References

[1] KnoppR., HumbletP. A.. Information capacity and power control in single-cell multiuser communications [C]. IEEE International Conference on Communication, 1995, Seattle, IEEE Press: 331-335

[2] DavidN. T.. Optimal power allocation over parallel gaussian broadcast channels [C]. IEEE International Symposium on Information Theory, 1997, Ulm, IEEE Press: 27

[3] WANG H, CHEN B. Asymptotic distributions and peak power analysis for uplink OFDMA signals [C]// IEEE International Conference on Acoustics, Speech, and Signal Processing: IEEE Press, 2004: 1085–1088.

[4] HomayounN., KnutS. Lidsheim.. Random phase updating algorithm for OFDM transmission with low PAPR [J]. IEEE Transaction on Broadcasting, 2002, 48(2): 123-128

[5] KouY., LuW., AntoniouA.. A new peak-to-average power-ratio reduction algorithm for OFDM systems via constellation extension [J]. IEEE Transaction on Wireless Communications, 2007, 6(5): 1823-1832

[6] DaeW.-l., JongS.-n., ChiW.-l., HabongChung.. A new SLM OFDM scheme with low complexity for PAPR reduction [J]. IEEE Signal Processing Letters, 2005, 12(2): 93-96

[7] JiangT., YaoW.-b., GuoP., SongY.-h., QuD.-ming.. Two novel nonlinear companding schemes with iterative receiver to reduce PAPR in multicarrier modulation systems [J]. IEEE Transaction on Broadcasting, 2006, 52(2): 268-273

[8] MoureloJ. T.Peak to average power ratio reduction for multicarrier modulation [D], 1999, Stanford, University of Stanford

[9] SeungsooY., SeoknoY., SunY. K., SongI.. A novel PAPR reduction scheme for OFDM systems: Selective mapping of partial tones (SMOPT) [J]. IEEE Transaction on Consumer Electronics, 2006, 52(1): 40-43

[10] WangL.-q., ChinthaTellambura.. A simplified clipping and filtering technique for PAR reduction in OFDM systems [J]. IEEE Signal Processing Letters, 2005, 12(6): 453-456

[11] IMRAN Baig, VARUN Jeoti. A new ZCT precoded OFDM system with pulse shaping: PAPR analysis [C]// IEEE Asia Pacific Conference Circuits and Systems (APCCAS). IEEE Press, 2010: 1131–1134.

[12] ImranB., VarunJeoti.. On the PAPR reduction in OFDM systems: A novel ZCT precoding based SLM technique [J]. Journal of Engineering Science and Technology (JESTEC), 2011, 6(3): 266-378

[13] TASI Ying-ming, ZHANG Guo-dong, WANG Xiao-dong. Orthogonal Polyphase codes for constant envelope OFDM-CDMA system [C]// IEEE Wireless Communications and Networking. IEEE Press, 2006: 1396–1401.

[14] BRANISLAV M Popović. Spreading sequences for multi-carrier CDMA systems [C]// IEE Colloquium CDMA Techniques and Applications for Third Generation Mobile Systems. London, 1997: 8/1–8/6.