Communications: directive radio wave systems and devices (e.g. – Directive – Position indicating
Patent
1994-10-26
1996-12-10
Blum, Theodore M.
Communications: directive radio wave systems and devices (e.g.,
Directive
Position indicating
342465, 342442, 342446, G01S 302
Patent
active
055835171
ABSTRACT:
A multi-path resistant frequency-hopped spread spectrum mobile vehicle or personal location system is described which provides low cost manufacture and low power operation while still enabling the accurate location of the mobile unit over long distances and in moderate to severe multi-path conditions. The frequency-hopped spread spectrum mobile vehicle or personal location system consists of a central station, a plurality of base stations and a plurality of mobile transmitters which transmit using a frequency-hopped spread-spectrum differential bi-phase shift keying communication signal. Frequency Shift Keying modulation may also be used. Each of the plurality of base stations include an array of receiving dipole antennas and employs special algorithms for retrieving very low power frequency-hopped spread spectrum signals in a noisy and multi-path environment. The base stations use computational algorithms for determining the phase difference between each of receiving dipole antennas to determine the direction of the transmitter relative to the location of the respective base station. The multiple direction of arrival angles of the received signal at each base station are corrected based on an n-dimensional ambiguity space to locate most probable angles of arrival. The ambiguity space plot is used to eliminate erroneous comparisons of dissimilar phases of the incoming signal. The most probable values are then tracked over multiple frequency hops and a histogram analysis of the strongest surviving angles of arrival is performed. The two peaks of the histogram are used as the two most probable directions of arrival. Each base station then communicates the two relative directions of the transmitter to a central station where the location of the transmitter is determined by triangulation. The direction of arrival angles from the multiple base stations are summed in a least mean square approach to find a single direction of arrival which is then plotted on a gnomonic projection to correct for the curvature of the earth.
REFERENCES:
patent: 2437695 (1948-03-01), Jansky
patent: 3445847 (1969-05-01), Hammack
patent: 3747104 (1973-07-01), Pansini
patent: 3864681 (1975-02-01), Olive
patent: 3886554 (1975-05-01), Braun et al.
patent: 3972042 (1976-07-01), Johnson
patent: 4114155 (1978-09-01), Raab
patent: 4188629 (1980-02-01), Johnson
patent: 4217586 (1980-08-01), McGuffin
patent: 4229620 (1980-10-01), Schaible
patent: 4316191 (1982-02-01), Sawatari et al.
patent: 4369426 (1983-01-01), Merkel
patent: 4443801 (1984-04-01), Klose et al.
patent: 4449127 (1984-05-01), Sanchez
patent: 4494119 (1985-01-01), Wimbush
patent: 4589078 (1986-05-01), Rosenberg
patent: 4596988 (1986-06-01), Wanka
patent: 4626859 (1986-12-01), Stansfield
patent: 4665379 (1987-05-01), Howell et al.
patent: 4665404 (1987-05-01), Christy et al.
patent: 4698781 (1987-10-01), Cockerell, Jr.
patent: 4728959 (1988-03-01), Maloney et al.
patent: 4740792 (1988-04-01), Sagey et al.
patent: 4742357 (1988-05-01), Rackley
patent: 4791572 (1988-12-01), Green, III et al.
patent: 4891650 (1990-01-01), Sheffer
patent: 4905271 (1990-02-01), Namekawa
patent: 5003317 (1991-03-01), Gray et al.
patent: 5021794 (1991-06-01), Lawrence
patent: 5055851 (1991-10-01), Sheffer
patent: 5081667 (1992-01-01), Drori et al.
patent: 5099245 (1992-03-01), Sagey
patent: 5218367 (1993-06-01), Sheffer et al.
patent: 5311197 (1994-05-01), Sorden et al.
patent: 5317323 (1994-05-01), Kennedy et al.
patent: 5327144 (1994-07-01), Stilp et al.
patent: 5365451 (1994-11-01), Wang et al.
patent: 5372411 (1994-12-01), Gerstenmaier et al.
patent: 5379047 (1995-01-01), Yokev et al.
patent: 5396540 (1995-03-01), Gooch
Ernest Jacobs et al., "Ambiguity Resolution in Interferometry," IEEE Transactions on Aerospace and Electronic Systems, 17, No. 6, pp. 776/780 dated Nov., 1981.
Mati Wax, et al., "Decentralized Processing in Sensory Arrays," IEEE Transactions on Acoustics, Speech and Signal Processing, ASSP-33, No. 4, pp. 1123-1129, dated Oct. 1985.
Harel Haim
Meiman Yehouda
Peleg Shimon
Yokev Hanoch
Blum Theodore M.
NEXUS 1994 Limited
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