Method and system for maritime high speed broadband communication networking

• US 9,608,793 B2
• Filed: 05/16/2012
• Issued: 03/28/2017
• Est. Priority Date: 05/16/2011
• Status: Active Grant

• Current Assignee: Kongsberg Discovery As
• Original Assignee: Kongsberg Seatex AS (Government of Norway)
• Inventors: Berntsen, Per Christian, Rinnan, Arne, Rosshaug, Harald Fossum
• Primary Examiner(s): Pasia, Redentor
• Application Number:
  US14/116,391
• Publication Number:
  US 20140086191A1
• Time in Patent Office: 1,777 Days
• US Class Current: 1/1
• CPC Class Codes: H01Q 1/34 Adaptation for use in or on ships, submarines, buoys or torpedoes for subaqueous use H01Q1/04
• CPC Class Codes: H01Q 3/30 varying the relative phase between the radiating elements of an array H01Q3/2605, H01Q3/2658, H01Q3/2682, H01Q3/44 take precedence
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0619 using feedback from receiving side feedback signaling for adaptive modulation/coding H04L1/0001
• CPC Class Codes: H04B 7/0862 receiver computing weights based on information from the transmitter
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04L 5/0058 Allocation criteria
• CPC Class Codes: H04W 4/02 Services making use of location information

Abstract

Method and system for providing an integrated long range, high capacity communication system between several entities involved in maritime Simultaneous Operations (SIMOPS). The method and system makes use of narrow lobe phase steerable antenna being controllable in both azimuth and elevation by software control.

Claims

1. A method for setting up a maritime high speed broadband communication network between several users (11) cooperating in a maritime SIMOPS operation, which users are provided with a user unit (100) including a user control unit (101), communication unit (102), an interface unit (103) and a user interface (104), comprising the following steps:

a) each user (11) performing a scan for other users (11) or issuing an interrogation message asking operative, location, heading, velocity and user identification status of other users via a phase steerable antenna (106) generating one narrow lobe,

b) forming a network (110) via which the users (11) can communicate directly with each other via each user setting up a database including operative users (11) with respective positions, headings and velocities identified,

c) calculating optimized transmission parameters, directly from one user (11) to another user (11) by measuring signal strength, signal-to-noise ratio, data throughput and other optional transmission parameters,

d) optimizing direction of the narrow lobe of the phase steerable antenna (106) in both azimuth and elevation for best possible data throughput for each user (11) directly to the respective other users (11),

e) reducing interference from reflected signals by performing at least one from the group consisting of (i)-(iv);

(i) Pointing one antenna lobe directly at a transmitting user (11) and pointing one lobe towards a reflection point, and introducing an additional phase shift on measured reflected signal in such a way that it will always add the reflected signal to the direct signal;

(ii) calculating direction and position of a reflection point based on position of the transmitting and receiving user (11), distance between transmitting and receiving user (11) and antenna height at both sides, and generating one or more nulls in the steerable phase antenna'"'"'s diagram in direction of the reflection point;

(iii) monitoring characteristics of a reflection point by establishing a dedicated monitoring channel using a reflection path, either by monitoring received signal only, or by using a dedicated pilot signal with known parameters and modulation transmitted from the transmitting user (11); and

(iv) splitting the antenna lobe of the receiving user (11) into two portions, aligning one antenna lobe portion with direct free space path and the other antenna lobe portion directly to a reflection point, and delaying the direct signal to be in phase with the reflected signal, thereby creating a constructive interference between the direct and the reflected signal and canceling the negative influence of the reflected signal

f) controlling the phase steerable antennas (106) for users (11) communicating directly with each other based on optimized transmission parameters from step (c), antenna lobe directions from step (d), and reducing interference from reflected signals from step (e) to achieve high gain in both azimuth and elevation for the generated narrow lobes,

g) repeating steps (a)-(f) at predetermined intervals.

2. The method of claim 1, wherein step a) includes performing a search both in azimuth and elevation, via one narrow lobe, to cover all possible transmission paths directly between respective users (11).

3. The method of claim 2, comprising performing the search over 360 degrees in azimuth and 90 degrees in elevation.

4. The method of claim 1, wherein step (f) includes one or more of the following steps:

increasing transmit power or reducing transmission speed to achieve optimized transmission parameters for direct communication between respective users (11),

steering the narrow lobe of the phase steerable antenna (106) to a direction having highest energy content between the respective users (11), and

forming the narrow lobe of the phase steerable antenna (106) by individually controlling the phase of each single antenna element in the narrow lobe phase steerable antenna (106).

5. The method of claim 4, comprising one or both of:

forming a narrow lobe phase steerable antenna (106) beam having one or more deep nulls, as well as narrow beams, and

tailoring a narrow lobe phase steerable antenna (106) directional diagram to the most suitable form for the actual application.

6. The method of claim 1, comprising generating several main lobes in different directions in order to simultaneously communicate directly with several different users (11).

7. The method of claim 1, comprising exchanging data and information directly between the respective users (11) by software controlled network architecture including point-to-point, point-to-multipoint or meshed network.

8. The method of claim 7, comprising combining the different network architectures if point-to-point is not possible, by setting up a meshed network for reaching users (11) not being directly available by point-to-point.

9. The method of claim 7, comprising establishing a mesh network and transmitting a prioritized message through several routes via several other users (11) at the same time.

10. The method of claim 9, comprising using controlled delay in each unit of the mesh network to avoid collision between messages from different routes and ensuring that the receiving user receives all messages from the different routes in a controlled manner.

11. The method of claim 1, comprising the step of checking identity or encoding/decoding of signals.

12. The method of claim 1, comprising limiting information or data flow by marking separate messages with a priority designation, the messages being processed in order of relative degree of priority.

13. The method of claim 12, wherein if throughput of data is determined to be low, messages are prioritized according to the priority designation to prioritize the most important messages.

14. The method of claim 1, comprising one or more of the following steps:

actively monitoring communication channels and using only free channels, thereby avoiding interference with other systems, and

actively compensating beam steering algorithms with regard to movement of the users (11) by using information from a movement sensor in order to maintain a correct antenna lobe position in both azimuth and elevation.

15. The method of claim 1, comprising using geographical position data for each user (11) to select frequencies and power levels for an actual area and automatically controlling the phase steerable antenna (106) according to the selected frequencies and power levels.

16. The method of claim 1, comprising measuring path delay and computing the direct distance between the respective users (11) or measuring beam angles and time of flight of messages directly between respective users (11) and computing direct distance between the respective users (11).

17. The method of claim 1, comprising locally generating differential correction signals for position identification which can be used by any user (11) in an associated network.

18. The method of claim 1, comprising updating a user interface with received data at predefined periods.

19. The method of claim 1, comprising measuring the distance directly from a user (11) to one or more fixed units with known distances to provide a correction factor for distance that can be applied for measurement toward other users.

20. The method of claim 1, comprising suppressing interfering signals by steering antenna zero points towards an interfering source or adjusting lobe elevation to an optimum interference free angle for reception.

21. The method of claim 1, comprising optimizing the signal-to-interference ratio by either maximising the signal level or minimising the interfering signal level.

22. The method of claim 1, wherein the step (e) of reducing interference is via sub-step (iv), comprising:

the receiving user (11) pointing a narrow lobe directly at the reflection point,

analysing the received signal and measuring predetermined characteristic parameters for the reflection point,

creating a model of behaviour of reflecting surface and reflected signal,

using the model to estimate correction signals, and

using the estimated correction signals for correction of a main signal.

23. The method of claim 1, wherein the step (e) of reducing interference is via sub-step (iv), comprising:

the transmitting user (11) transmitting a dedicated carrier modulated signal with a known code word sequence directly towards the reflection point,

the receiving user (11) recording the signal after the signal is reflected by a reflecting surface,

generating an estimated correction signal by correlating, the received signal and the transmitted signal, and

correcting a main signal with the estimated correction signal.

24. The method of claim 1, comprising predicting the position of the users (11) based on available information for position, heading and velocity and directing the antenna lobe toward the predicted position.

25. The method of claim 1, comprising the step of performing ranging between the respective users (11) by:

transmitting one or more addressed ranging message from one user (11) to at least one other user (11),

receiving users (11) responding with confirmation messages to the transmitting user (11) after receipt and decoding a message, and

calculating the distance between transmitting user (11) to receiving user (11) based on time delay from transmission to receipt.

26. The method of claim 1, comprising performing ranging between the respective users (11) by:

transmitting one or more ranging message from one user (11) to one or more named other user (11),

responding users (11) introducing a controlled delay corresponding to their identity and responding with confirmation messages including controlled delay and identify to the transmitting user when the respective messages are received and decoded as a ranging messages, and

calculating distance between the respective users (11) based on time delay from transmission to reception and controlled time delay.

27. The method of claim 25, wherein phase measurements of the received signal are used to increase the accuracy of the ranging.

28. The method of claim 25, comprising comparing the calculated distance with measured GPS or DGPS distance.

29. The method of claim 1, comprising reducing interference by:

measuring or identifying noisy frequencies and directions to interference sources and storing the information in a database,

using adaptive optimization algorithm to analyse the interference source and direction based on one or more of the following interference characteristics;

frequency, amplitude, timing, duration and history, and

controlling the phase steerable antenna (106) to form nulls in the direction of the interference source or by forming of a signal adapted to counteract the interference signal, and thereby block the signal from the interference sources.

30. The method of claim 1, comprising detecting interference from electric equipment or faulty transmitters onboard other users (11) includes:

searching for the direction of one or more interference sources originating from one or more users (11) by phase steerable antennas (106), and

computing position and distance to the interference source using information from the users (11).

31. The method of claim 30, wherein the position and distance to the interference sources are used to control the phase steerable antenna (106) to form nulls in the direction of the one or more interference sources and thereby blocking the signal from the interference sources.