Robust matched-filter acquisition for direct-sequence ultrawideband systems
Tai-Jung Huang
Longyan University, Institute of Mathematics and Information Engineering
Jing Huang Lecturer
Longyan University, Institute of Mathematics and Information Engineering
DOI: https://doi.org/10.59429/pmcs.v7i1.9515
Abstract
In this paper, we propose and analyze a rapid acquisition loop for a direct-sequence ultrawideband (DS-UWB) system called robust matched-filter acquisition, which is mainly aimed at eliminating the cases of false alarm in signal acquisition. Moreover, we present a study on the acquisition performances of the serial search, conventional matched filter, and robust matched filter in UWB dense multipath environments. The mean acquisition time, the acquisition probability, and the mean number of false alarms are evaluated for CM1- CM4 channel models. We find that the robust matched-filter acquisition provides a significant improvement in performances over the conventional matched-filter algorithm for the specific UWB channel model. UWB (Ultra Wideband) wireless communication system is very suitable to short-distance and high-data-rate wireless communication, because it has the characters of higher data rate, shorter communication distance, and low average transmission power. UWB systems ensure certain fixed synchronized error between the transmitted and received ends. In the thesis, we will focus on the issue of synchronization performance analysis to do further discuss and study. In real communication channel environment, multipath factor contributes a lot of severe interference to data transmission whereas it happens more severely in dense metropolitan area. Conventionally, we use Rake receiver to receive the signal in order to reduce such multipath-caused interference. However, using Rake receiver, we required to know the delay time and attenuated amount of each transmitted route in advance. Furthermore if we needs to gather more signal energy, it is necessary for us to add more “fingers” at Rake receiver. Nevertheless it will increase complexity of the hardware. To avoid such situation happening, we adopt the concept of DHTR (Delay-Hopped Transmitted- reference) that correlates the delayed signal with original one to avoid the design issue of template signal. In the proposed scheme, we are able to reduce the complexity problem of the Rake receiver system. Besides, we further present the performance analysis of such system to make the study more complete, also provide a convincing proof to the simulation.
References
[1] R. A. Scholtz, “Multiple access with time hopping impulse modulation”, Proc. MILCOM’93, 1993-Oct.-11.
[2] M. Z. Win, R. A. Scholtz and M. A. Barnes, “Ultra-wide bandwidth signal propagation for indoor wireless communications”, Proc. IEEE Int. Conf. Commun., vol. 1, pp. 56-60, 1997-Jun.
[3] M. Z. Win and R. A. Scholtz, “Impulse radio: How it works”, IEEE Commun. Lett., vol. 2, no. 2, pp. 36-38, Feb. 1998.
[4] M. Z. Win and R. A. Scholtz, “On the robustness of ultra-wide bandwidth signals in dense multipath environments”, IEEE Commun. Lett., vol. 2, no. 2, pp. 51-53, Feb. 1998.
[5] M. Z. Win and R. A. Scholtz, “Ultra-wide bandwidth time-hopping spread-spectrum impulse radio for wireless multiple access communications”, IEEE Trans. Commun., vol. 48, no. 4, pp. 679-689, Apr. 2000.
[6] M. Z. Win and R. A. Scholtz, “Characterization of ultra-wide bandwidth wireless indoor channels: A communication-theoretic view”, IEEE J. Sel. Areas Commun., vol. 20, no. 9, pp. 1613-1627, Dec. 2002.
[7] S. S. Kolenchery, J. K. Townsend and J. A. Freebersyer, “A novel impulse radio network for tactical military wireless communications”, Proc. MILCOM’98, pp. 59-65, 1998-Oct.-18.
[8] R. R. Rick and L. B. Milstein, “Optimal decision strategies for acquisition of spread-spectrum signals in frequency-selective fading channels”, IEEE Trans. Commun., vol. 46, no. 5, pp. 686-694, May 1998.
[9] Y. Ma, F. Chin, B. Kannan and S. Pasupathy, “Acquisition performance of an ultrawideband communications system over a multiple aceess fading channel”, Proc. IEEE Conf. Ultra-Wideband Syst. Technol., pp. 99-103, 2002-May.
[10] E. A. Homier and R. A. Scholtz, “Rapid acquisition of ultrawideband signals in the dense multipath channel”, Proc. IEEE Conf. Ultra-Wideband Syst. Technol., pp. 105-109, 2002-May.
[11] 11. S. Gezici, E. Fishler, F. Kobayashi, H. V. Poor and A. F. Molisch, “A rapid acquisition technique for impulse radio”, Proc. IEEE Pacific Rim Conf. Commun. Comput. Signal Process., pp. 627-630, 2003-Aug.
[12] Z. Thian and G. B. Giannakis, “Data-aided ML timing acquisition in ultrawideband radios”, UWBST’03, 2003-Nov.
[13] L. Reggiani and G. M. Maggio, “A reduced-complexity acquisition algorithm for UWB impulse radio”, UWBST’03, 2003-Nov.
[14] J. Foerster and Q. Li, UWB channel modeling contribution from Intel, Jun. 2002.
[15] S. M. Kay, Fundamentals of Statistical Signal Processing: Detection Theory, NJ, Englewood Cliffs:Prentice-Hall, vol. II, 1998.
[16] J. G. Proakis, Digital Communications, New York:McGraw-Hill, 1995.
[17] A. J. Viterbi, CDMA Principles of Spread Spectrum Communication, MA, Reading:Addison-Wesley, 1995.
[18] N. Balakrishnan and C. R. Rao, Order Statistics: Theory and Methods, The Netherlands, Amsterdam:Elsevier, 1998