Remote sensing using rayleigh signaling

Details Remote sensing using rayleigh signaling Remote sensing using rayleigh signaling

2003-07-15

2004-12-21

Gregory, Bernarr E. (Department: 3662)

Communications: directive radio wave systems and devices (e.g.,

With particular circuit

Display

C342S189000, C342S145000

Reexamination Certificate

active

06833809

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to a method and apparatus for sensing remote objects. More particular, the present invention relates to sensing remotes objects using unique and random signal waveforms in both space and time.
BACKGROUND OF THE INVENTION
Current techniques for search and track surveillance use an array of transmitter source elements (e.g., electromagnetic or acoustic) and an array of receiver sensor elements. The array of transmitter source elements generates one or more transmitted signal beams that the array of receiver sensor elements receives by forming beams, the received signals being scattered by remote objects. The received scattered signals are subsequently processed to yield direction and range information of remote objects. In many systems, the array of transmitter source elements and the array of receiver sensor elements share elements within a single array.
In the current techniques, only a limited number of signal beams can be formed simultaneously. Therefore, a remote object space (volume of coverage) must be sequentially scanned sector by sector until the complete remote object space of interest has been thoroughly scanned. A fast moving object traveling through the remote object space can escape detection simply because the signal beam is never directed toward the object at any instant. Also, in the current technique, simple countermeasures may affect the system. This is particularly true if the remote object space is sequentially scanned in the same manner repeatedly using the same signal waveform throughout the object space.
Therefore, there is a need to provide a method and apparatus for forming more beams simultaneously to reduce the likelihood that a remote object will escape detection. There is also a need to provide a method and apparatus for reducing the effects of countermeasures against the apparatus.
SUMMARY OF THE INVENTION
In accordance with the invention, there is provided an apparatus having a transmitter and a receiver for sensing remote objects. The transmitter comprises J transmitter source elements. The apparatus further comprises a source generator for providing J equal carrier signals and a modulator signal generator for generating J statistically independent chip sequences. Each chip sequence comprises a plurality of chips, each chip having a random phase. Still further, the apparatus comprises a modulator for independently modulating the J equal carrier signals with the J statistically independent chips sequences, respectively, to generate J modulated signals. Each modulated signal comprises a plurality of chips, each chip having a random phase. The J modulated signals are transmitted by the J transmitter source elements, respectively, forming a composite signal beam. The transmitter source elements are separated by approximately ½ wavelength.
There is also provided a method for sensing remote objects comprising the steps of generating J equal carrier signals and J statistically independent chip sequences. Each chip sequence comprises a plurality of chips, each chip having a random phase. The method further comprises independently modulating the J equal carrier signals with the J statically independent chip sequences, respectively, to generate J modulated signals and then transmitting the J modulated signals, forming a composite signal beam. Each modulated signal comprises a plurality of chips, each chip having a random phase.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.


REFERENCES:
patent: 3680100 (1972-07-01), Woerrlein
patent: 4028699 (1977-06-01), Stevens
patent: 4045796 (1977-08-01), Kline, Jr.
patent: 4130811 (1978-12-01), Katz et al.
patent: 4330876 (1982-05-01), Johnson
patent: 4965732 (1990-10-01), Roy et al.
patent: 5260968 (1993-11-01), Gardner et al.
patent: 5515378 (1996-05-01), Roy et al.
patent: 5566209 (1996-10-01), Forssen et al.
patent: 5592490 (1997-01-01), Barratt et al.
patent: 5619503 (1997-04-01), Dent
patent: 5649287 (1997-07-01), Forssen et al.
patent: 5722083 (1998-02-01), Konig
patent: 5732075 (1998-03-01), Tangemann et al.
patent: 5793798 (1998-08-01), Rudish et al.
patent: 5808580 (1998-09-01), Andrews, Jr.
patent: 5886988 (1999-03-01), Yun et al.
patent: 5909649 (1999-06-01), Saunders
patent: 5930290 (1999-07-01), Zhou et al.
patent: 5940742 (1999-08-01), Dent
patent: 6023514 (2000-02-01), Strandberg
patent: 6031485 (2000-02-01), Cellai et al.
patent: 6031865 (2000-02-01), Kelton et al.
patent: 6097714 (2000-08-01), Nagatani et al.
patent: 6107963 (2000-08-01), Ohmi et al.
patent: 6137433 (2000-10-01), Zavorotny et al.
patent: 6163564 (2000-12-01), Rudish et al.
patent: 6163566 (2000-12-01), Shiino
patent: 6240122 (2001-05-01), Miyashita
patent: 6275679 (2001-08-01), Elam et al.
patent: 6331837 (2001-12-01), Shattil
patent: 6362780 (2002-03-01), Butz et al.
patent: 6392588 (2002-05-01), Levanon
patent: 6580701 (2003-06-01), Ylitalo et al.
patent: 6608588 (2003-08-01), Elam
patent: 2001/0047503 (2001-11-01), Zhang
patent: 0893 703 (1999-01-01), None
patent: WO 93/12590 (1993-06-01), None
patent: WO 98/37654 (1998-08-01), None
S. Barbarossa, F. Cerquetti, “Simple Space-Time Coded SS-CDMA Systems Capable of Perfect MUI/SI Elimination,” IEEE Communications Letters, vol. 5, No. 12, Dec. 2001.
U.S. patent application No. 10/354,093, filed Jan. 30, 2003.
Chee Tiong Desmond NG, “Smart Antennas for Wireless Applications and Switched Beamforming,” Dept. of Information Technology and Electrical Engineering, The University of Queensland, Oct. 2001.
D. Giuli et al.;Radar Target Scattering Matrix Measurement Through Orthogonal Singals; IEE Proceedings-F, vol. 140, No. 4, pp. 233-242 (Aug. 1993).
Dr. Paul C. Chestnut et al., “Implementation of a Multiple Angle Estimator,” Sept. 23, 1983.
Chee Tiong Desmond NG, “Smart Antennas for Wireless Applications and Switched Beamforming,” Electrical Engineering Thesis Project, http://innovexpo.itee.uq.edu.au/2001/projects/s804113.
U.S. patent application No. 09/697,187, filed on Oct. 27, 2000.
Merrill Skolnik,Radar Handbook, Second Edition, pp. 2.16-2.23, McGraw Hill, 1990.

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