Increasing the Efficiency of Rake Receivers for Ultra-Wideband Applications

Authors: Aimilia P. Doukeli, Athanasios S. Lioumpas, George K. Karagiannidis, Panayiotis V. Frangos, P. Takis Mathiopoulos

Abstract:

In diversity rich environments, such as in Ultra- Wideband (UWB) applications, the a priori determination of the number of strong diversity branches is difficult, because of the considerably large number of diversity paths, which are characterized by a variety of power delay profiles (PDPs). Several Rake implementations have been proposed in the past, in order to reduce the number of the estimated and combined paths. To this aim, we introduce two adaptive Rake receivers, which combine a subset of the resolvable paths considering simultaneously the quality of both the total combining output signal-to-noise ratio (SNR) and the individual SNR of each path. These schemes achieve better adaptation to channel conditions compared to other known receivers, without further increasing the complexity. Their performance is evaluated in different practical UWB channels, whose models are based on extensive propagation measurements. The proposed receivers compromise between the power consumption, complexity and performance gain for the additional paths, resulting in important savings in power and computational resources.

Keywords: Adaptive Rake receivers, diversity techniques, fading channels, UWB channel.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1073549

References:

[1] M. Z. Win and Z. A. Kosti'c, "Virtual path analysis of selective Rake receiver in dense multipath channels," IEEE Commun. Lett., vol. 3, pp. 308-310, Nov. 1999.
[2] M. Z. Win, G. Chrisikos, and N. R. Sollenberger, "Performance of Rake reception in dense multipath channels: implications of spreding bandwidth and selection diversity order," IEEE J. Select. Areas Commun., vol. 18, pp. 1516-1525, Aug. 2000.
[3] M. Z. Win and G. Chrisikos, Wideband Wireless Digital Communications, ch. Impact of spreading bandwidth and selection diversity order on selective Rake reception. U.K.: Prentice-Hall, 2001, A. F. Molisch(ed.).
[4] J. D. Choi and W. E. Stark, "Performance of ultra-wideband communications with suboptimal receivers in multipath channels," IEEE J. Select. Areas Commun., vol. 20, pp. 1754-1766, Dec. 2002.
[5] M. Z. Win and R. A. Scholtz, "On the energy capture of ultra -wide bandwidth signals in dense multipath environments," IEEE Commun. Lett., vol. 2, pp. 245-247, Sept. 1998.
[6] Cassioli, D.; Win, M.Z.; Vatalaro, F.; Molisch, A.F. "Low Complexity Rake Receivers in Ultra-Wideband Channels", IEEE Trans. Wireless Commun, vol. 6, pp. 1265-1275, April 2007.
[7] M.K. Simon, and M.-S. Alouini, "Performance analysis of generalized selection combining with threshold test per branch (T-GSC)," IEEE Trans. Vehic. Tech., vol. 51, pp. 1018-1029, Sept. 2002.
[8] P. Gupta, N. Bansal, and R. K. Mallik, "Analysis of minimum selection H-S/MRC in Rayleigh fading," IEEE Trans. Commun., vol. 53, no. 5, pp. 780-784, May 2005.
[9] R. K. Mallik, P. Gupta, and Q. T. Zhang, "Minimum selection GSC in independent Rayleigh fading," IEEE Trans. Veh. Technol., vol. 54, no. 3, pp. 1013-1021, May 2005.
[10] H.-C. Yang, "New results on ordered statitics and analysis of minimum selection generalized selection combining (GSC)," IEEE Trans. Wireless Commun., vol. 5, no. 7, pp. 1876-1885, July 2006.
[11] M.-S. Alouini and H.-C. Yang, "Minimum estimation and combining generalized selection combining (MEC-GSC)," IEEE Trans. Wireless Commun., vol. 6, pp. 526-532, Feb. 2007.
[12] W. Li, J. Zhong and T. A. Gulliver, "A Low Complexity RAKE Receiver for Ultra-Wideband Systems," IEEE Vehicular. Technology Conference., vol. 3, pp. 1393-1396, Sept. 2005.
[13] A. F. Molisch, J. R. Foerster, and M. Pendergrass, "Channel models for ultrawideband personal area networks," IEEE Pers. Commun. Mag., vol. 10, pp. 14-21, Dec. 2003.
[14] D. Cassioli, M. Z. Win, and A. F. Molisch, "The UWB indoor channel: from statistical model to simulations," IEEE J. Select. Areas Commun., vol. 20, pp. 1247-1257, Aug. 2002.
[15] A. F. Molisch et al., "IEEE 802.15.4a channel model - final report,"Nov. 2004.
[16] M. Z. Win, R. A. Scholtz, and M. A. Barnes, "Ultra -wide bandwidth signal propagation for indoor wireless communications," in Proc. IEEE Int. Conf. Commun., vol. 1, pp. 56-60, June 1997, Montrİeal, CANADA.
[17] M. Z. Win and R. A. Scholtz, "Characterization of ultra-wide bandwidth wireless indoor channels: A communication-theoretic view," IEEE J. Select. Areas Commun., vol. 20, pp. 1613-1627, Dec. 2002.
[18] A. A. Saleh and R. A. Valenzuela, "A statistical model for indoor multipath propagation," IEEE J. Select. Areas Commun., vol. 5, pp. 128-137, Feb. 1987.
[19] J. R. Foerster, "Channel modeling sub-committee report final," in Tech. Rep. P802.15 02/490r1, IEEE 802.15 SG3a, Feb. 2003.