Blind Synchronization in Asynchronous UWB Networks Based on the Transmit-Reference Scheme
© Relja Djapic et al. 2006
Received: 15 September 2005
Accepted: 13 December 2006
Published: 24 January 2007
Ultra-wideband (UWB) wireless communication systems are based on the transmission of extremely narrow pulses, with a duration inferior to a nanosecond. The application of transmit reference (TR) to UWB systems allows to side-step channel estimation at the receiver, with a tradeoff of the effective transmission bandwidth, which is reduced by the usage of a reference pulse. Similar to CDMA systems, different users can share the same available bandwidth by means of different spreading codes. This allows the receiver to separate users, and to recover the timing information of the transmitted data packets. The nature of UWB transmissions—short, burst-like packets—requires a fast synchronization algorithm, that can accommodate several asynchronous users. Exploiting the fact that a shift in time corresponds to a phase rotation in the frequency domain, a blind and computationally effcient synchronization algorithm that takes advantage of the shift invariance structure in the frequency domain is proposed in this paper. Integer and fractional delay estimations are considered, along with a subsequent symbol estimation step. This results in a collision-avoiding multiuser algorithm, readily applicable to a fast acquisition procedure in a UWB ad hoc network.
- Djapic R, Leus G, van der Veen A-J: Blind synchronization in asynchronous UWB networks based on the transmit-reference scheme. Proceedings of 38th Asilomar Conference on Signals, Systems, and Computers (ACSSC '04), November 2004, Pacific Grove, Calif, USA 2: 1506–1510.Google Scholar
- Djapic R, Leus G, van der Veen A-J: Synchronization and detection for transmited reference UWB systems. Proceedings of the Asilomar Conference on Signals, Systems, and Computers (ACSSC '05), October/November 2005, Pacific Grove, Calif, USA 1084–1088.Google Scholar
- Yang L, Giannakis GB: Ultra-wideband communications. IEEE Signal Processing Magazine 2004,21(6):26–54. 10.1109/MSP.2004.1359140View ArticleGoogle Scholar
- Bagga S, Serdijn WA, Long JR: A PPM Gaussian monocycle transmitter for ultra-wideband communications. International Workshop on Ultra Wideband Systems; Joint with Conference on Ultra Wideband Systems and Technologies, May 2004, Kyoto, Japan 130–134.Google Scholar
- Cassioli D, Win MZ, Molisch AF: The ultra-wide bandwidth indoor channel: from statistical model to simulations. IEEE Journal on Selected Areas in Communications 2002,20(6):1247–1257. 10.1109/JSAC.2002.801228View ArticleGoogle Scholar
- Win MZ, Scholtz RA: On the robustness of ultra-wide bandwidth signals in dense multipath environments. IEEE Communications Letters 1998,2(2):51–53. 10.1109/4234.660801View ArticleGoogle Scholar
- Win MZ, Scholtz RA: Ultra-wide bandwidth time-hopping spread-spectrum impulse radio for wireless multiple-access communications. IEEE Transactions on Communications 2000,48(4):679–691. 10.1109/26.843135View ArticleGoogle Scholar
- Win MZ, Scholtz RA: Impulse radio: how it works. IEEE Communications Letters 1998,2(2):36–38. 10.1109/4234.660796View ArticleGoogle Scholar
- Gagliardi R: A geometrical study of transmitted reference communication systems. IEEE Transactions on Communication Technology 1964,12(4):118–123. 10.1109/TCOM.1964.1088960MathSciNetView ArticleGoogle Scholar
- Hoctor R, Tomlinson H: Delay-hopped transmitted-reference RF communications. IEEE Conference on Ultra Wideband Systems and Technologies (UWBST '02), May 2002, Baltimore, Md, USA 265–270.
- van Stralen N, Dentinger A, Welles K II, Gauss R Jr., Hoctor R, Tomlinson H: Delay hopped transmitted reference experimental results. IEEE Conference on Ultra Wideband Systems and Technologies (UWBST '02), May 2002, Baltimore, Md, USA 93–98.
- Leus G, van der Veen A-J: Noise suppression in UWB transmitted reference systems. IEEE 5th Workshop on Signal Processing Advances in Wireless Communications (SPAWC '04), July 2004, Lisbon, Portugal 155–159.
- Trindade A, Dang QH, van der Veen A-J: Signal processing model for a transmit-reference UWB wireless communication system. IEEE Conference on Ultra Wideband Systems and Technologies (UWBST '03), November 2003, Reston, Va, USA 270–274.
- Dang QH, van der Veen A-J, Trindade A: Statistical analysis of a transmit-reference UWB wireless communication system. Proceedings of IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP '05), March 2005, Philadelphia, Pa, USA 3: 317–320.
- Torlak M, Xu G: Blind multiuser channel estimation in asynchronous CDMA systems. IEEE Transactions on Signal Processing 1997,45(1):137–147. 10.1109/78.552212View ArticleGoogle Scholar
- Hoctor R, Tomlinson H: Delay-hopped transmitted-reference RF communications. IEEE Conference on Ultra Wideband Systems and Technologies(UWBST '02), May 2002, Washington, DC, USA 265–269.
- Dang Q, Trindade A, van der Veen A-J, Leus G: Signal model and receiver algorithms for a transmit-reference ultra-wideband communication system. IEEE Journal on Selected Areas in Communications 2006,24(4, part 1):773–779.View ArticleGoogle Scholar
- Irahhauten Z, Janssen GJ, Nikookar H, Yarovoy A, Ligthart LP: UWB channel measurements and results for office and industrial environments. IEEE International Conference on Ultra-Wideband (ICUWB '06), September 2006, Waltham, Mass, USA
- van der Veen A-J, Vanderveen MC, Paulraj AJ: Joint angle and delay estimation using shift-invariance properties. IEEE Signal Processing Letters 1997,4(5):142–145. 10.1109/97.575559View ArticleGoogle Scholar
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