TY  - JOUR
T1  - Novel OFDM System Using Orthogonal Pilot Symbols with Subcarrier Index Modulation
AU  - Aldırmaz Çolak, Sultan
AU  - Acar, Yusuf
PY  - 2019
DA  - October
DO  - 10.17694/bajece.588919
JF  - Balkan Journal of Electrical and Computer Engineering
PB  - MUSA YILMAZ
WT  - DergiPark
SN  - 2147-284X
SP  - 440
EP  - 445
VL  - 7
IS  - 4
LA  - en
AB  - In this work, two new transmission schemes areproposed to increase the spectral efficiency of orthogonal frequency divisionmultiplexing (OFDM). In practical OFDM systems, channel estimation is usuallyperformed by employing pilot symbols which is based on inserting known symbolsin the time-frequency domain. However, pilot symbol designing is one of thebottlenecks of OFDM systems limiting the increase of spectral efficiency. Weapply new pilot design structures, which are use orthogonal Walsh-Hadamardcodes. To increase the spectral efficiency of OFDM systems, we assign the extrabits to the index of the each orthogonal Walsh-Hadamard codes. Simulation andtheoretical results show that proposed methods have better performance thanconventional OFDM with higher spectral efficiency. Moreover, no more energy is spentfor additional information carried in the indices compared to classical OFDMsystems. As a result, proposed methods provide both spectral efficiency andenergy efficiency.
KW  - Orthogonal frequency division multiplexing (OFDM)
KW  - subcarrier index modulation (SIM)
KW  - channel estimation
CR  - [1] R. Nee, P. Ramjee, “OFDM for wireless multimedia communications,” Artech House, Inc., 2000.
CR  - [2] K. Fazel, S. Kaiser. Multi-carrier and spread spectrum systems: from OFDM and MC-CDMA to LTE and WiMAX. John Wiley & Sons, 2008.
CR  - [3] M. Ergen, Mobile broadband: including WiMAX and LTE. Springer Science & Business Media, 2009.
CR  - [4] B. Kamislioglu and A.Akbal, “Effect of doubly selective channels about bit error probability in OFDM and FBMC,” European Journal of Technique, Vol. 7 No.2, 2017, pp. 96-101.
CR  - [5] M. C. Necker and G. L. Stuber, ‘‘Totally blind channel estimation for ofdm on fast varying mobile radio channels,’’ IEEE Trans. Wireless Comm., Vol.3, No.5, 2004, pp. 1514-1525.
CR  - [6] Y. Acar, H . Dogan, E. Basar, and E. Panayirci, ‘‘Interpolation based pilot aided channel estimation for stbc spatial modulation and performance analysis under imperfect CSI,’’ IET Comm., Vol.10, No.14, 2016, pp. 1820-1828.
CR  - [7] Y. Acar, H. Dogan, and E. Panayirci, ‘‘Pilot symbol aided channel estimation for spatial modulation-OFDM systems and its performance analysis with different types of interpolations’’, Wireless Personal Communications, Vol.94, No.3, 2017, pp. 1387-1404.
CR  - [8] Y. Acar, S. Aldırmaz and E. Başar, ‘‘Channel estimation for OFDM-IM systems,’’ Turkish Journal of Electrical Engineering \& Computer Sciences, 2019, 27.3: 1908-1921.
 
[9] B. Özbek,  R. Yılmaz . "The Adaptive Channel Estimation For STBC-OFDM Systems". IU-Journal of Electrical & Electronics Engineering 5 (2011): 1333-1340.
CR  - [10] B. Kamişlioğlu, A. AKBAL, "LSE Channel Estimation and Performance Analysis of OFDM Systems". Fırat University Turkish Journal of Science and Technology 12 (2017 ): 53-57
CR  - [11] Y. Liu, et al. ‘‘Channel estimation for OFDM. IEEE Communications Surveys \& Tutorials, 2014, 16.4: 1891-1908.
CR  - [12] R. Mesleh, H. Haas, C.W. Ahn,, and S. Yun, “Spatial modulation-a new low complexity spectral efficiency enhancing technique”, 2006 First International Conference on Communications and Networking, China (pp. 1-5). IEEE., October 2006.
CR  - [13] Y. Acar, ‘‘Subblock Aided OFDM with Index Modulation,” Balkan Journal of Electrical and Computer Engineering, 7 (2) , 156-161, (2019). DOI: 10.17694/bajece.514324
CR  - [14] S. Aldırmaz, Y. Acar, and E. Basar. "Adaptive dual-mode OFDM with index modulation." Physical Communication 30 (2018): 15-25.
CR  - [15] Y. Acar, and T. Cooklev. "High performance OFDM with index modulation." Physical Communication 32 (2019): 192-199.
CR  - [16] E. Basar, M. Wen, R. Mesleh, M. Di Renzo, Y. Xiao, and H. Haas, ‘‘Index modulation techniques for next-generation wireless networks,’’ IEEE Access, Vol.5, 2017, pp. 16693-16746.
CR  - [17] Q. Wang, G. Dou, X. He, R. Deng, J. Gao, “Novel OFDM System Using Data-Nulling Superimposed Pilots With Subcarrier Index Modulation”, IEEE Communications Letters, Vol. 22, No.10, 2018, pp. 2164-2167.
CR  - [18] D. A. Bell, ‘‘Walsh functions and Hadamard matrixes,’’ IET Electronics Letter, Vol.2, No.9, 1966, pp. 340-341
UR  - https://doi.org/10.17694/bajece.588919
L1  - https://dergipark.org.tr/en/download/article-file/843754
ER  -