This paper proposes a two-dimensional spreading method in UMTS Long Term Evolution (LTE). Such a method brings additional time-frequency diversity which is beneficial in terms of the ability to decode transmitted data at the receiver site under multipath fading. Additional diversity is provided due to the fact that chips of transmitted signals are spread using a Walsh-Hadamard spreading sequence over several subcarriers as well as over several time-slots simultaneously. A comparison with state-of-the-art LTE downlink transmission is provided. To enable reproducibility and to increase credibility of our results, an open source Vienna LTE simulator is utilized. LTE transmissions with the proposed 2D spreading are tested on several channel models. Simulations show that apart from an Additive White Gaussian Noise channel model, this 2D spreading based method outperforms the throughput performance of standard LTE. At high Signal to Noise Ratio (SNR), the throughput increase in most channel models is higher than 10 %.
LTE simulator homepage. [Online]. Available: http://www.nt.tuwien.ac.at/ltesimulator/
Mehlführer, C., Wrulich, M., Ikuno, J. C., Bosanska, D., & Rupp, M. (2009). Simulating the long term evolution physical layer. In European signal processing conference (EUSIPCO). Scotland: Glasgow, August 2009.
Mehlführer, C., Colom Ikuno, J., Simko, M., Schwarz, S., Wrulich, M., & Rupp, M. (2011). The Vienna LTE simulators—Enabling reproducibility in wireless communications research. in EURASIP Journal on Advances in Signal Processing, 2011(1), 29. [Online]. Available: http://asp.eurasipjournals.com/content/2011/1/29.
Maeda, N., Kishiyama, Y., Atarashi, H., & Sawahashi, M. (2003). Variable spreading factor-ofcdm with two dimensional spreading that prioritizes time domain spreading for forward link broadband wireless access. in Vehicular technology conference, 2003. VTC 2003-Spring. The 57th IEEE semiannual (Vol. 1, pp. 127–132), April 2003.
Atarashi, H., Maeda, N., Abeta, S., & Sawahashi, M. (2002). Broadband packet wireless access based on VSF-OFCDM and MC/DS-CDMA. In The 13th IEEE international symposium on personal, indoor and mobile radio communications, 2002 (Vol. 3, pp. 992–997), September 2002.
Maeda, N., Atarashi, H., Abeta, S., & Sawahashi, M. (2002). Throughput comparison between VSF-OFCDM and OFDM considering effect of sectorization in forward link broadband packet wireless access. In Vehicular Technology Conference, 2002. Proceedings. VTC 2002-Fall. 2002 IEEE 56th (Vol. 1, pp. 47–51).
Blumenstein J., Fedra Z., Sebesta V. (2010) Performance of pilot aided channel estimation technique in 2D spreading based systems. Radioengineering 19: 507–510
Chong, C.-C., Watanabe, F., Inamura, H., Wang, D., Minn, H., & Al-Dhahir, N. (2008). On the performance comparison of VSF-OFCDM and OFDM. In IEEE 19th international symposium on personal, indoor and mobile radio communications, 2008 (PIMRC 2008) (pp. 1 –6), September 2008.
Sesia S., Toufik I., Baker M. (2009) LTE, The UMTS long term evolution: From theory to practice. Wiley, New York
ITU IMT-2000. (1997). Recommendation ITU-R m.1225: Guidelines for evaluation of radio transmission technologies for IMT-2000. Technical report.
3GPP. (2007). Technical specification group radio access network; deployment aspects (release 7). 3GPP, Technical report 25.943 V7.0.0, January 2007.
Fazel, K., & Kaiser, S. (2008). Multi-carrier and spread spectrum systems: From OFDM and MC-CDMA to LTE and WiMAX. Wiley. [Online]. Available: http://books.google.com/books?id=RzUJsPqe-dgC
3GPP Technical Specification Group RAN. (2009). E-UTRA; physical channels and modulation. 3GPP, Technical report TS 36.211 Version 8.7.0, May 2009.
3GPP Technical Specification Group RAN. (2009). E-UTRA; multiplexing and channel coding. 3GPP, Technical report TS 36.212, March 2009.
3GPP Technical Specification Group RAN. (2009). E-UTRA; physical layer procedures. 3GPP, Technical report TS 36.213, March 2009.
Hanzo, L. (2003). OFDM and MC-CDMA for broadband multi-user communications, WLANs, and broadcasting. Wiley. [Online]. Available: http://books.google.com/books?id=hQ6bl3RG04sC
This work has been funded by the Christian Doppler Laboratory for Wireless Technologies for Sustainable Mobility, KATHREINWerke KG, and A1 Telekom Austria AG. The financial support by the Federal Ministry of Economy, Family and Youth and the National Foundation for Research, Technology and Development is gratefully acknowledged. The Grant Agency of Czech Republic grant no. P102/10/P513 “Communication systems combining OFDM and CDMA and their PAPR” is also gratefully acknowledged. The authors would like to thank Josep Colom Ikuno for many fruitful and interesting discussions on this and related topics. The research published in this submission was financially supported by the project CZ.1.07/2.2.00/20.0007 WICOMT of the operational program Education for competitiveness.
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Blumenstein, J., Šimko, M., Marsalek, R. et al. Two Dimensional Signal Spreading in UMTS LTE: Exploiting Time-Frequency Diversity to Increase Throughput. Wireless Pers Commun 71, 1109–1119 (2013). https://doi.org/10.1007/s11277-012-0864-3
- 2D Spreading
- Throughput maximization
- Vienna LTE simulator