David Lee/Ernst Weber Professor
Director, NYU WIRELESS
Prof. of Electrical and Computer Eng
Prof. of Computer Science
Prof. of Radiology
We are actively researching ways of miniaturizing the circuits required to construct a sliding correlator channel sounder. The following diagrams outline at a very high level concepts we have developed that would allow a complete channel sounder to be implemented directly on-chip.
Channel sounding has been conducted since at least the 1950s. A sliding correlator channel sounder, first used by researchers such as D. Cox in the early 1970s, uses a spread-spectrum signal to excite the wireless channel. The received signal is then correlated with a slightly slower but identical spread-spectrum signal at the receiver. This has the effect of simulating a pulse excitation of the channel with the added benefit of time dilation, allowing very high bandwidth measurements to be made with fairly low bandwidth recording technology.
The following diagrams outline at a very high level how we plan to take this classic technique to the 21st century.
We are actively researching ways of implementing both the transmitter and receiver portions of the channel sounder completely on-chip. This involves both baseband circuit design (for the baseband signal processing) as well as IF/RF circuit design for various frequency bands. On a separate research project, we are actively conducting channel measurement campaigns of the 60 GHz channel. We will use what we learn about the 60 GHz channel to improve our on-chip channel sounder designs.
W.G. Newhall, T. S. Rappaport, D. G. Sweeney, “A Spread Spectrum Sliding Correlator System for Propagation Measurements,” RF Design, pp. 40-54, Apr. 1996.
G. Martin, “Wideband Channel Sounding Dynamic Range using a Sliding Correlator,” IEEE Vehi. Tech. Conf., pp. 2517-2521, May 2000.
W.G. Newhall, K. Saldanha, T. S. Rappaport, “Using RF Channel Sounding Measurements to Determine Delay Spread and Path Loss,” RF Design, pp. 82-88, Jan. 1996.
For more information about sliding correlator channel sounders, please refer to the list of publications below. This is only a sample; a complete list of Prof. Rappaport's publications can be found here.
C. R. Anderson, T. S. Rappaport, "In-building wideband partition loss measurements at 2.5 and 60 GHz," IEEE Transactions on Wireless Communications, Vol. 3, No. 3, May 2004, pp. 922-928.
C. R. Anderson, "Design and Implementation of an Ultrabroadband Millimeter-Wavelength Vector Sliding Correlator Channel Sounder and In-Building Multipath Measurements at 2.5 & 60 GHz," Thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Electrical Engineering, May 6, 2002. Advised by Prof. Rappaport
C. R. Anderson, T. S. Rappaport, K. Bae, et al. "In-Building wideband multipath characteristics at 2.5 and 60 GHz," Proceedings of IEEE 2002 Vehicular Technology Conference, 2002, pp. 97-101.
H. Xu, T. S. Rappaport, R. J. Boyle, et. al., "Measurements and Models for 38-GHz Point-to-Multipoint Radiowave Propagation," IEEE Journal on Selected Areas in Communications, Vol. 18, No. 3, March 2000.
H. Xu, T. S. Rappaport, R. J. Boyle, et. al., "38-GHz wide-band point-to-multipoint measurements under different weather conditions," IEEE Communications Letters, Vol. 4, No. 1, January 2000, pp. 7-8.
G. Durgin, T. S. Rappaport, H. Xu, "5.85-GHz Radio Path Loss and Penetration Loss Measurements In and Around Homes and Trees," IEEE Communications Letters, Vol. 2, No. 3, March 1998.
J. B. Andersen, T. S. Rappaport, S. Yoshida, "Propagation Measurements and Models for Wireless Communication Channels," IEEE Communications Magazine, Vol. 33, No. 1, January 1995.
S. Y. Seidel and T. S. Rappaport, "Site-Specific Propagation Prediction for Wireless In-Building Personal Communication System Design," IEEE Transactions on Vehicular Technology, Vol. 43, No. 4, November 1994.
M. J. Feurstein, K. L. Blackard, T. S. Rappaport, et. al., "Path loss, delay spread, and outage models as functions of antenna height for microcellular system design," IEEE Transactions on Vehicular Technology, Vol. 43, No. 3, August 1994, pp. 487-498.
S. Y. Seidel and T. S. Rappaport, "A ray tracing technique to predict path loss and delay spread inside buildings," Proceedings of IEEE 1992 GLOBECOM Global Telecommunications Conference, December 1992.
S. Y. Seidel and T. S. Rappaport, "914 MHz path loss prediction models for wireless communications in multifloored buildings," IEEE Transactions on Antennas and Propagation, Vol. 40, No. 2, February 1992, pp. 207-217.
S. Y. Seidel, T. S. Rappaport, S Jain, "Path loss, scattering and multipath delay statistics in four European cities for digital cellular and microcellular radio telephone," IEEE Transactions on Vehicular Technology, Vol. 40, No. 4, November 1991, pp. 721-730.
T. S. Rappaport, S. Y Seidel, R. Singh, "900 MHz multipath propagation measurements for US digital cellular radio telephone," Proceedings of IEEE 1989 GLOBECOM Global Telecommunications Conference, November 1989.
D. C. Cox, "Delay Doppler Characteristics of Multipath Propagation at 910 MHz in a Suburban Mobile Radio Environment," IEEE Transactions on Antennas and Propagation, Vol. AP-20, No. 5, September 1972.