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WP3.3: Steerable antenna technologies: Signal processing aspects

Participants: UoY (18MM); POLITO (19MM); EUCON (6MM)

Tim Tozer & Yuriy Zakharov

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Workpackage Tasks

Beamforming for HAPs (UoY)In particular, for communications with high-speed trains

Beamforming for ground terminals (POLITO)In particular, installed on high-speed trains

Implementation aspects (EUCON)In DSP software

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Explore Terminal Constraints

Geometry Size / Mass Speed

(Pointing, Doppler)

Etc.

Explore System Requirements

Link Budgets Tracking /

Availability Polarisation Geometry Etc.

Philosophy for both WP 3.2 & 3.3

Identify promising solutions

Explore enhancements

Assessment of most promising solutions in terms of requirements

Develop enhancements

Develop selected

promising concepts

Explore Prior Art

Antennas Associated

Signal Processing

Agree Requiremen

ts Spec

time

M0

M4

M12

End Mar 04

Identify Signal

Processing Issues.

Develop interestin

g SP aspects?

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WP3.3 Input from other WPs

RF aspects of steerable antennas (from WP3.2)Antenna array architectureVariation / tolerances in antenna array geometry; calibration aspects (real-time calibration; reliability of antenna array elementsVariation / tolerances in delays, phase shifts, element gains/weights, etc.

Communication signal structure (from WP2.1)

Propagation (from WP2.2)Fading correlation of received signals over the antenna aperture and timeMultipath structure of received signals (number of multipath components, angle and delay profiles)

Platform stability (from test trials??)

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WP3.3 Milestones & Deliverables

Internal Milestones + Documents, Month 5: a) Possible approaches for RF, EM and Mechatronic Aspects of Train & HAP antennas.b) Possible approaches for Signal Processing Aspects of Train & HAP antennas.

Month 12: Possible antenna topologies for ground terminals and aerial platforms identified

Month 24: Beamforming algorithms and implementation aspects for ground terminals and aerial platforms specified

Month 34: Detailed design of adaptive beamforming algorithms for ground terminal and aerial platform antennas

Deliverables

D17: Report on adaptive beamforming algorithms for advanced antenna types for aerial platform and ground terminals (M27).

D28: Report detailing the implementation aspects of signal processing for aerial platform and ground terminal beamformers (M36).

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Antenna geometry options

Overlapping subarrays Simplify the feed network, RF part and signal processing

Vertical antennasNon-traditional foot-print

Random element positionsDispersed array structureErrors in element positions

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Methodology

Asymptotic theoretical analysis

Computer simulation of proposed techniques

Extrapolation of concepts from “Underwater acoustic antenna arrays”

Valuable pedigree from digital beamforming for large acoustic arrays

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Research topics

Adaptive algorithms:Simple implementation (DSP software, FPGA & ASIC hardware platforms)Low power consumption

Algorithms for matrix computationsSolution of linear systems of equationsMatrix inversionEigenvalue decomposition

Effect of errorsLook direction and steering vector errorsElement failure and element position errorsWeight errors

Antenna array calibration

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Dichotomous Coordinate Descent Dichotomous Coordinate Descent (DCD) algorithm (DCD) algorithm

Real-time solutions to large systems of linear equationsFixed-point oriented algorithm (software implementation on a DSP platform)Does not involve multiplications or divisions (hardware implementation on FPGA & ASIC)Fast convergence

Current applications Echo cancellationEqualisationMultiuser detectionTomography

Possible applicationsAdaptive algorithmsMatrix inversionEigenvalue decomposition

Publications: Zakharov Y. V. and Tozer T. C. “Data processing, particularly in communication systems”, Patent Application, GB0208329.3, WO03088076, Published Oct. 2003. Zakharov Y. V. and Tozer T. C. “Equation solving”, Patent Application, GB0324191.6, US10/685983, Filed Oct. 2003. Zakharov Y. V. and Tozer T. C. “Box-constrained multiuser detection based on multiplication-free coordinate descent optimisation”, ICASSP’2004, Submitted.

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Reminder: WP 3.2 - Steerable antenna technologies: EM, RF and mechatronics aspects

Start date: M0 Participants : UOY (16MM) CSEM (31MM) SkyLINC (1MM) CRL (5MM?)

Objectives:To investigate the antenna electromagnetic, RF and mechanical aspects for the mobile mm-wave broadband delivery and put forward solutions for the critical components .Outline Description 1: Aperture Antennas

To determine impact of statistical variability of real antenna parameters on performance characteristics of the system as a whole . Mathematical tools based on real antenna specifications & measurements developed to calculate system performance & variation

2: Smart AntennasStudy smart antenna configurations to determine suitability for moving platforms. Consider smart antenna types, technologies and topologies. a) Fast Trains b) HAP antenna array.Feasibility of implementing the required RF hardware will be investigated. Solutions will also relate to the signal processing (beamforming algorithms) activity WP3.3

3: mm-wave RF front end.

Deliverables: D24 Steerable antenna architectures and critical RF circuits performance. (M35)Milestones: M6. HAP payload antenna statistical variance. Concepts for “train” antennas including mechatronics. M12. RF circuit constraints. Design experiment for validation of concepts.

M18. Model mm-wave active element performance for steerable antenna implementation.M30. Test evaluation and specification of preferred solution for steerable antenna

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Reminder WP 3.3 - Steerable antenna technology: Signal processing aspects

Start date: M0 Participants : UOY (18MM) POLITO (19MM) EUCON (6MM)

Objectives:Investigation of advanced adaptive beamforming technologies not previously considered to determine applicability to aerial platform applications and their expected performance within HAP communications scenarios. To design a vehicular steerable antenna such as might be deployed on a train. To enable communication with an aerial platform anywhere within the coverage area.Outline Description 1: Beamforming Antennas

Design to establish & improve communication link between HAP and ground terminals. Design of an adaptive beamformer on-board of the platform, exploiting fast adaptability of an electronically steered beam pattern.

2: Beamforming algorithms for ground terminal antennas Implementing adaptive beamforming solution at the CPEs and on vehicles, to continuously track HAP trajectory.

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Reminder WP 3.3 /contd

3: Implementation aspects of beamforming algorithmsWill define the mm-wave equipment specification and characteristics required for smart antenna implementation. The specification will include both a transmit and receive chain configurations, noise performance, output power, linearity, filtering requirements, etc. The work will also define the interface to the software radio IF.

4: Beamforming AlgorithmsImplementation aspects of signal processing algorithms. Technological issues such as quantisation, fixed/floating point algebra, design optimisation in terms of power and computational efficiency. Aimed at implementation of selected algorithms on DSP. The performance will be assessed by simulating real working conditions.

DeliverablesD17: Adaptive beamforming algorithms for advanced antenna types for aerial platform

and ground terminals (M27).D28: Implementation aspects of signal processing for beamformers (M36).  Milestones and expected resultsM12: Possible antenna topologies for ground terminals and aerial platformsM24: Beamforming algorithms & implementation aspects for those terminalsM34: Detailed design of adaptive beamforming algorithms