Communications bandwidth enhancement using orthogonal spatial division multiplexing

• US 9,813,145 B2
• Filed: 03/09/2015
• Issued: 11/07/2017
• Est. Priority Date: 03/09/2015
• Status: Active Grant

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Orbital ATK Inc. (Northrop Grumman Corporation)
• Inventors: Atkinson, Leonard A.
• Primary Examiner(s): Masur, Paul H
• Application Number:
  US14/642,225
• Publication Number:
  US 20170085315A1
• Time in Patent Office: 974 Days
• CPC Class Codes: G01S 11/06 using intensity measurements
• CPC Class Codes: G01S 5/0294 Trajectory determination or predictive filtering, e.g. target tracking or Kalman filtering
• CPC Class Codes: G01S 5/06 Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/12 takes precedence
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: G06Q 10/0833 Tracking
• CPC Class Codes: G06Q 30/0201 Market modelling; Market analysis; Collecting market data
• CPC Class Codes: G06T 7/246 using feature-based methods, e.g. the tracking of corners or segments
• CPC Class Codes: G06T 7/292 Multi-camera tracking
• CPC Class Codes: G06T 7/77 using statistical methods
• CPC Class Codes: G06V 20/52 Surveillance or monitoring of activities, e.g. for recognising suspicious objects recognising microscopic objects G06V20/69
• CPC Class Codes: G06V 2201/10 Recognition assisted with metadata
• CPC Class Codes: G06V 40/20 Movements or behaviour, e.g. gesture recognition recognition of facial expressions G06V40/16
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/0697 using spatial multiplexing
• CPC Class Codes: H04B 7/18515 Transmission equipment in satellites or space-based relays
• CPC Class Codes: H04J 2011/0009 with FDM/FDMA
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 4/021 Services related to particular areas, e.g. point of interest [POI] services, venue services or geofences
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Systems and methods are described herein for communications bandwidth enhancement using Orthogonal Spatial Division Multiplexing (OSDM). For example, large sparse antenna arrays may be able to distinguish between signals emitted by multiple nearly collocated antennas, even if the signals have the same frequency, polarization, and coverage. Thus, the use of a large sparse antenna array may be able to resolve/isolate individual antennas on a single platform, allowing for OSDM, analogous to Orthogonal Frequency Divisional Multiplexing (OFDM). Using OSDM, multiple antennas on the same vehicle are able to reuse the same frequencies/polarizations without interference, thereby increasing spectrum availability while still providing the same transmitter power spectral density and total RF power emission.

Claims

1. A method for transmitting signals from multiple antennas from a communications platform, the method comprising:

receiving, at a first receiving station, a first combined signal comprising a first signal transmitted by a first antenna and a second signal transmitted by a second antenna, wherein;

the first signal and the second signal are transmitted at a single frequency, and

the first antenna and the second antenna are separated by a first distance;

receiving, at a second receiving station, a second combined signal comprising the first signal transmitted by the first antenna and the second signal transmitted by the second antenna, wherein;

the first receiving station and the second receiving station are separated by a second distance; and

determining the first signal and the second signal based on the received first combined signal and the received second combined signal;

wherein the second distance of separation between the first receiving station and the second receiving station is based on the first distance of separation between the first antenna and the second antenna such that an additive array factor is provided resulting in a peak on one of the first antenna and second antenna and a null on the other of the first antenna and second antenna, and wherein determining the first signal and the second signal is further based on the additive array factor.

2. The method of claim 1 wherein the first antenna and the second antenna are on a single satellite, aircraft, or other structure.

3. The method of claim 1 wherein the first antenna and the second antenna are on different satellites, aircraft, or other structures.

4. The method of claim 1 further comprising:

receiving, at a third receiving station, a third combined signal comprising the first signal transmitted by the first antenna and the second signal transmitted by the second antenna, wherein;

the third combined signal is different than the first combined signal and the second combined signal,

the third receiving station and the second receiving station are separated by a third distance.

5. The method of claim 4, wherein the third distance is equal to the second distance.

6. The method of claim 1, wherein the first combined signal and the second combined signal further comprise a third signal transmitted by a third antenna, wherein:

the first signal, the second signal, and the third signal are transmitted at the single frequency, and

the third antenna and the second antenna are separated by a third distance.

7. The method of claim 6, wherein the third distance is equal to the first distance.

8. The method of claim 1, wherein the second distance is larger than the first distance.

9. The method of claim 1, wherein the first antenna and the second antenna are located at a geostationary earth orbit.

10. The method of claim 1, wherein the first distance is a function of the satellite antenna spacing, satellite range, and signal wavelength.

11. A system for transmitting signals from multiple antennas, the system comprising:

a first receiving station configured to receive a first combined signal comprising a first signal transmitted by a first antenna and a second signal transmitted by a second antenna, wherein;

the first signal and the second signal are transmitted at a single frequency, and

the first antenna and the second antenna are separated by a first distance;

a second receiving station configured to receive a second combined signal comprising the first signal transmitted by the first antenna and the second signal transmitted by the second antenna, wherein;

the first receiving station and the second receiving station are separated by a second distance; and

processing circuitry configured to determine the first signal and the second signal based on the received first combined signal and the received second combined signa;

wherein the second distance of separation between the first receiving station and the second receiving station is based on the first distance of separation between the first antenna and the second antenna such that an additive array factor is provided resulting in a peak on one of the first antenna and second antenna and a null on the other of the first antenna and second antenna, and wherein determining the first signal and the second signal is further based on the additive array factor.

12. The system of claim 11, wherein the first antenna and the second antenna are on a single satellite, aircraft, or other structure.

13. The system of claim 11, wherein the first antenna and the second antenna are on different satellites, aircrafts, or other structures.

14. The system of claim 11, further comprising a third receiving station configured to receive a third combined signal comprising the first signal transmitted by the first antenna and the second signal transmitted by the second antenna, wherein:

the third combined signal is different than the first combined signal and the second combined signal,

the third receiving station and the second receiving station are separated by a third distance.

15. The system of claim 14, wherein the third distance is equal to the second distance.

16. The system of claim 11, wherein the first combined signal and the second combined signal further comprise a third signal transmitted by a third antenna, wherein:

the first signal, the second signal, and the third signal are transmitted at the single frequency, and

the third antenna and the second antenna are separated by a third distance.

17. The system of claim 16, wherein the third distance is equal to the first distance.

18. The system of claim 11, wherein the second distance is larger than the first distance.

19. The system of claim 11, wherein the first antenna and the second antenna are located at a geostationary earth orbit.

20. The system of claim 11, wherein the first distance is a function of the satellite antenna spacing, satellite range, and signal wavelength.