Novel OFDM transmission scheme using generalized prefix with subcarrier index modulation

The cyclic prefix (CP) is a prefix technique widely used in orthogonal frequency division multiplexing (OFDM) systems in order to eliminate the intersymbol interference (ISI) caused by the dispersion of wireless channels. However, CP reduces the number of symbols that can be transmitted in one OFDM symbol. Therefore, CP is one of the bottlenecks of OFDM systems limiting their spectral efficiency (SE). This limitation on the SE of the classical CP-based OFDM system is the main motivation for this work to introduce a novel method. In this paper, the design of a new CP structure, which is based on the generalized prefix (GP), is presented. In the proposed structure, extra bits are assigned to the GP structure to increase the SE of OFDM systems. Simulation results show that the proposed method has the same performance as conventional CP-based OFDM but higher spectral efficiency. Specifically, it is shown that the proposed method has 5.5% more spectral efficiency than the classical OFDM system. A simple algorithm is also proposed to detect the additional information bits conveyed by GP. As a result, the proposed method provides both high spectral efficiency and low computational complexity.

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[1] Proakis JG. Digital Communications. New York, NY, USA: McGraw-Hill, 1995
[2] Dahlman E, Parkvall S, Skold J. 4G: LTE/LTE-Advanced for Mobile Broadband. Boston, MA, USA: Academic Press, 2013.
[3] Nee R, Ramjee P. OFDM for Wireless Multimedia Communications. London, UK: Artech House, Inc., 2000.
[4] Huemer M, Hofbauer C, Huber JB. Unique word prefix in SC/FDE and OFDM: A comparison. In: IEEE 2010 GLOBECOM; USA; 2010; 1296-1301.
[5] Muck M, Courville M, Duhamel P. A pseudorandom postfix OFDM modulator semi-blind channel estimation and equalization. IEEE Transactions on Signal Processing 2006; 54 (3): 1005-1017.
[6] Hou Y, Hase T. New OFDM system without guard interval. In: IEEE International Conference Consumer Electronic; Las Vegas, NV, USA; 2009; 1-2.
[7] Muquet B, Wang Z, Giannakis GB, Courville M, Duhamel P. Cyclic prefixing or zero padding for wireless multicarrier transmissions?. IEEE Transaction on Communications, 2002; 50 (2): 2136-2148.
[8] Rousseaux O, Leus G, Moonen M. Estimation and equalization of doubly selective channels using known symbol padding. IEEE Transactions on Signal Processing 2006; 54 (3): 979-990.
[9] Ozan W, Ryan G, Izzat D. Zero padding or cyclic prefix: evaluation for non-orthogonal signals. IEEE Communications Letters 2020; 24 (3): 690-694.
[10] Muck M, Alexandre RD, Courville M, Duhamel P. A pseudo random postfix OFDM based modulator for Multiple antennas systems. IEEE Communications Society 2004; 2392-2396.
[11] Hofbauer C, Haselmayr W, Huemer M. Pilot tone insertion and utilization in unique word OFDM. In: IEEE 21st International Workshop on Signal Processing Advances in Wireless Communications (SPAWC); Georgia, USA; 2020; 1-5.
[12] Fletcher PN. Iterative decoding for reducing cyclic prefix requirement in OFDM modulation. Electronics Letters 2003; 39 (6): 539-541.
[13] Cooklev T, Dogan H, Cintra RJ, Yildiz H. A generalized prefix construction for OFDM systems over quasi-static channels. IEEE Transactions on Vehicular Technology 2011; 60 (8): 3684-3693.
[14] Acar Y, Cooklev T. High performance OFDM with index modulation. Physical Communication 2019; 32: 192-199.
[15] Cooklev T. Improved prefix for OFDM-based cognitive radios. Electronics letters 2012; 48 (4): 240-241.
[16] Yıldız H, Acar Y, Cooklev T, Dogan H. Generalised prefix for space–time block-coded orthogonal frequency division multiplexing wireless systems over correlated multiple-input multiple-output channels. IET Communications 2014; 8 (9): 1589-1598.
[17] Basar E, Aygolu Ü, Panayırcı E, Poor HV. Orthogonal frequency division multiplexing with index modulation. IEEE Transactions on Signal Processing 2013; 61 (22): 5536-5549.
[18] Mesleh RY, Haas H, Sinanovic S, Ahn CW, Yun S. Spatial modulation. IEEE Transactions on Vehicular Technology 2008; 57 (4): 2228-2241.
[19] Mesleh R, Ikki SS, Aggoune HM. Quadrature spatial modulation. IEEE Transactions on Vehicular Technology 2014; 64 (6): 2738-2742.
[20] Basar E. Reconfigurable intelligent surface-based index modulation: A new beyond MIMO paradigm for 6G. IEEE Transactions on Communications 2020; 68 (5): 3187-3196.
[21] Mao T, Wang Z, Wang Q, Chen S, Hanzo L. Dual-mode index modulation aided OFDM. IEEE Access 2016; 5: 50-60.
[22] Wang Q, Dou G, He X, Deng R, Gao J. Novel OFDM system using data-nulling superimposed pilots with subcarrier index modulation. IEEE Communications Letters 2018; 22 (10): 2164-2167.
[23] Acar Y, Aldirmaz-Colak S. Novel OFDM System using orthogonal pilot symbols with subcarrier index modulation. Balkan Journal of Electrical and Computer Engineering 2019; 7 (4): 440-445. doi: 10.17694/bajece.588919
[24] Acar Y, Aldirmaz-Colak S. A new spectrally efficient pilot scheme for OFDM systems. AEU - International Journal of Electronics and Communications 2020. doi: 10.1016/j.aeue.2020.153566
[25] Nakao M, Ishihara T, Sugiura S. Single-carrier frequency-domain equalization with index modulation. IEEE Communications Letters 2016; 21 (2): 298-301.
[26] Gursoy M C, Basar E, Pusane AE, Tugcu T. Index Modulation for Molecular Communication via Diffusion Systems. IEEE Transactions on Communications 2019; 67( 5): 3337-3350.
[27] Rahman T, Habib A, Sacchi C, El-Hajjar M. Mm-wave STS Kaided single carrier block transmission for broadband networking. In: The 22nd IEEE Symposium on Computers and Communications (ISCC); Heraklion, Greece; Jul. 3-6 2017. pp. 507–514.
[28] Sacchi C, Rahman TF, Hemadeh IA, El-Hajjar M. Millimeterwave transmission for small-cell backhaul in dense urban environment: A solution based on MIMO-OFDM and space-time shift keying (STSK). IEEE Access 2017, 5, 4000-4017.
[29] Basar E, Wen M, Mesleh R, Di Renzo M, Xiao Y et al. Index modulation techniques for next-generation wireless networks. IEEE Access 2017; 5: 16693-16746.
[30] Ianniello J. Time delay estimation via cross-correlation in the presence of large estimation errors. IEEE Transactions on Acoustics, Speech, and Signal Processing 1982; 30 (6): 998-1003.
[31] Li J, Wu R. An efficient algorithm for time delay estimation. IEEE Transactions on Signal Processing 1998; 46 (8): 2231-2235.
[32] Reed F, Feintuch P, Bershad N. Time delay estimation using the LMS adaptive filter–static behavior. IEEE Transactions on Acoustics, Speech, and Signal Processing 1981; 29 (3): 561-571.
[33] Azaria M, Hertz D. Time delay estimation by generalized cross correlation methods. IEEE Transactions on Acoustics, Speech, and Signal Processing 1984; 32 (2): 280-285.
[34] Bjorklund S, Ljung L. A review of time-delay estimation techniques. In: 42nd IEEE International Conference on Decision and Control; Maui, HI, USA, 3: 2502-2507.
[35] Jacovitti G, Scarano G. Discrete time techniques for time delay estimation. IEEE Transactions on Signal Processing 1993; 41 (2): 525-533.
[36] Hale D. An efficient method for computing local cross-correlations of multi-dimensional signals 2006; CWP Report 656: 1:7.
[37] Tarokh V, Jafarkhani H, Calderbank AR. Space-time block codes from orthogonal designs, IEEE Transactions on Information Theory 1999; 45 (5): 1456-1467.