On the Implementation of a Probabilistic Equalizer for Low-Cost Impulse Radio UWB in High Data Rate

Sami MEKKI, Jean-Luc DANGER, Benoit MISCOPEIN

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DOI: 10.4236/wsn.2009.14031                

Abstract

This paper treats the digital design of a probabilistic energy equalizer for impulse radio (IR) UWB receiver in high data rate (100Mbps). The aim of this study is to bypass certain complex mathematical function as a chi-squared distribution and reduce the computational complexity of the equalizer for a low cost hardware implementation. As in Sub-MAP algorithm, the max* operation is investigated for complexity reduction and tested by computer simulation with fixed point data types under 802.15.3a channel models. The obtained re-sults prove that the complexity reduction involves a very slight algorithm deterioration and still meet the low-cost constraint of the implementation.

Keywords

Impulse Radio Ultra-Wideband, Probabilistic Energy Equalizer, Inter-Symbol Interference, Chi-Squared

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	L. Yang and G. B. Giannakis, “Ultra-wideband communica-tions: an idea whose time has come,” IEEE Signal Processing Magazine, Vol. 21, No. 6, pp. 26–54, November 2004.
[2]	J. D. Choi and W. E. Stark, “Performance of ultra-wide- band communications with suboptimal receivers in multipath chan-nels,” IEEE Journal on Selected Areas in Communications, Vol. 20, No. 9, pp. 1754–1766, December 2002.
[3]	R. Hoctor and H. Tomlinson, “Delay-hopped transmitted ref-erence RF communications,” IEEE Conference on Ul-tra-Wideband Systems and Technologies, pp. 265–269, May 2002.
[4]	V. Lottici, L. Wu, and Z. Tian, “Inter-symbol interference mitigation in high-data-rate uwb systems,” IEEE International Conference on Communications, pp. 4299–4304, June 2007.
[5]	Y. Zhang, H. Wu, Q. Zhang, and P. Zhang, “Interference miti-gation for coexistence of heterogeneous ultra-wide- band sys-tems”, EURASIP Journal on Wireless Communications and Networking, pp. 1–13, 2006.
[6]	M. E. Sahin and H. Arslan, “Inter-symbol interfrence in high data rate uwb communications using energy detector receiv-ers,” IEEE International Conference on UWB, ICU, pp. 176–179, September 2005.
[7]	S. Mekki, J. L. Danger, B. Miscopein, J. Schwoerer and J. J. Boutros, “Probabilistic equalizer for ultra-wideband energy detection,” IEEE 67th Vehicular Technology Conference (VTC), pp. 1108–1112, May 2008.
[8]	M. Abramowitz and I. A. Stegun, Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables, December 1972.
[9]	J. A. Erfanian and S. Pasupathy, “Low-complexity paral-lel-structure symbol-by-symbol detection for ISI channels,” IEEE Pacific Rim Conf. Communications, Computers and Signal Processing, pp. 350–353, 1989.
[10]	A. J. Viterbi, “An intuitive justification and a simplified im-plementation of the MAP decoder for convolutional codes,” IEEE Journal On Selected Areas In Communications, Vol. 16, No. 2, pp. 260–264, February 1998.
[11]	H. Urkowitz, “Energy detection of unknown deterministic sig-nals,” Proceedings of the IEEE, Vol. 55, No. 4, pp. 523–531, April 1967.
[12]	A. H. M. Ross, “Algorithm for calculating the noncentral chis-quare distribution,” IEEE Transactions on Information Theory, Vol. 45, No. 4, pp. 1327–1333, May 1999.
[13]	N. C. Severo and M. Zelen, “Normal approximation to the chisquared and non-central F probability functions,” Biometrika, Vol. 47, No. 3/4, pp. 411–416, December 1960.
[14]	L. Canal, “A normal approximation for the chi-square distribu-tion,” Computational Statistics & Data Analysis, Vol. 48, No. 4, pp. 803–808, April 2005.
[15]	J.-T. Zhang, “Approximate and asymptotic distributions of chi-squared-type mixtures with applications,” Journal of the American Statistical Association, Vol. 100, pp. 273–285, March 2005.
[16]	R. Saadane, D. Aboutajdine, A. M. Hayar, and R. Knopp, “On the estimation of the degrees of freedom of in-door UWB channel,” IEEE 61st, Vehicular Technology Conference (VTC), Vol. 5, pp. 3147–3151, May 2005.
[17]	J. G. Proakis, Digital Communications, Second Edition, New York, McGraw Hill, 1989.
[18]	J. Foerster, “Channel modeling sub-committee report final,” IEEE P802.15-02/368r5-SG3a, Tech. Rep., 18 November 2002.
[19]	S. Mekki, J. L. Danger, B. Miscopein, and J. J. Boutros, “EM channel estimation in a low-cost UWB receiver based on en-ergy detection,” IEEE International Symposium on Wireless Communication Systems 2008 (ISWCS 08), pp. 214–218, Oc-tober 2008. [Online]. Available: http://samimekki.free.fr/.
[20]	“Digital video broadcasting (DVB); interaction channel for satellite distribution systems,” ETSI EN 301 790 V.1.3.1, Tech. Rep., March 2004.
[21]	“Digital video broadcasting (DVB); interaction channel for satellite distribution systems; guidelines for the use of en 301 790,” ETSI TR 101 790 V.1.2.1, Tech. Rep., January 2003.
[22]	“TC1000-xX DVB-RCS Turbo Decoder v2.1,” TurboConcept, Tech. Rep., February 2005.
[23]	AD8318 1 MHz to 8 GHz, 70 dB Logarithmic Detec-tor/Controller. [Online]. Available: http://www.analog. com/en/prod/0%2C2877%2CAD8318%2C00.html.
[24]	SystemC User’s Guide, version 2.0. [Online]. Available: http://www.systemc.org.
[25]	W. J. Gross and P. G. Gulak, “Simplified MAP algorithm suit-able for implementation of turbo decoders,” Electron ics Letters, Vol. 34, No. 16, pp. 1577–1578, August 1998