European Space Agency

Mobile Telecom Payload - RF Measurement System

Objectives

Mobile satellite-based communications systems will be introduced into the markets in increasing numbers. Satellite transponders carrying traffic of such systems demand challenging capabilities both from the transponder payload and from the test systems used to validate them.

We outline the customer requirements capturing the requirements of a generic MTP-RMS that supports testing and verifying mobile communications payloads. The Device Under Test (DUT) for MTP-RMS is given in the Figure. It resembles a simplified block diagram of the Unit/System to be tested and verified with the MTP-RMS, which comprises RMS FORWARD and RMS RETURN directions.


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Challenges

The main problem areas are:

  • Realistic simulation of signal traffic requiring hundreds of narrowband carriers.
  • Several modulation schemes have to be supported simultaneously on the multi-carrier stimulation.
  • Bandwidths of generated signals will exceed several 100 MHz, despite consisting of individual narrowband carriers.
  • Software facilities required for generating meaningful stimulation patterns have to be developed, that are compatible with today’s instrumentation.
  • Each carrier arrives weak and is more susceptible to interference through non-nonlinearities than commonplace signals uplinked via feeders.
  • This is a further reason that completely new tests are required in order to validate the system via a suitable RMS.
  • Validation of system requires recurrent execution of a plethora of carrier configuration permutations.
  • This in turn requires rapid reconfiguration capabilities of the stimulation set-up in order to reduce the anticipated massive increase in overall measurement times.

 

Benefits

Astrium and also other European and US satellite manufactures see a big market opportunity in the upcoming “Multi-Band Mobile and Spot Beam Payloads”, although major technical challenges need to be solved in particular for the Payload EGSE. New and more demanding test methods are required for the many interfaces, test ports and carriers. As a consequence Astrium plans to renew their Payload Test System (PTS) by a new generic Telecom Payload Test System also suited to full-fill the requirements for the AIV/AIT of a Multi-Band Mobile Payload.

The PTS consists of three major parts, the Service Module Simulator (SMS), The RF-Measurement System (RMS) and the Test Software and Database Infrastructure. The RMS component defining the measurement science is the most critical and demanding component of the PTS. Therefore it is most likely the component Astrium and probably also other Telecom Satellite Manufactures are going to procure externally.

Due to our long term experience for RF and TT&C SCOE Systems and the Galileo PTS our core competence matches perfectly for the RMS. Driven by the above described business opportunity we plan to extend our EGSE product portfolio by a Generic Mobile Payload RMS which will be the baseline for turn-key EGSE solutions offered to Astrium and other satellite manufacturers.

Features

The Generic MTP-RMS software shall provide a generic infrastructure for the configuration of the system. Furthermore it shall supply a facility to automatically and manually running test procedures. Furthermore a set of measurement procedures shall be created and verified. Within these measurements procedures (generic) multi-carrier stimulation patterns have to be created dynamically that complement the actual measurement procedures (see below). In particular the software development shall comprise functionalities in the following generic areas:-

  • Multi-carrier test pattern generation system.
    Individual traffic carriers shall be composed into multi-carrier test-patterns. Each traffic carrier shall be modelled with respect to its modulation scheme by a set of individual tones that can be placed on a 100 Hz frequency raster, and for which the frequency, phase, and level shall be determined. Due to the high number of traffic carriers it cannot be assumed that each tone carrier will be entered manually for all of the generic stimulation scenarios. Therefore other means of (pseudo-)random generation of meaningful multi-carrier signal shall be implemented.
  • Measurement procedures execution system including remote.
    Execution shall be performed locally or shall be possible via external invocation mechanism.
  • Implementation of measurements.
    Each identified measurement shall be implemented. This shall also include a set of control routines for each measurement and stimulation instrument being used (instrument driver). Thereby a set of validated measurement procedures and a validated set of instrument drivers shall be obtained.

The following figure gives an overview about the System architecture of the MTP RMS:


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Plan

The following table contains the proposed Milestone-Reviews (MR) and Progress Meetings (PM) in accordance with the tender conditions. The Reviews MR1, MR2 and MR3 are also coordinated with the schedules of the Alphasat RMS project.

 

Milestone Review/Meeting  Date
 KO Kick Off  Aug 2008
 PM1 Progress Meeting 1  Sept 2008
 MR1  Detailed Design Review  Nov 2008
 PM2 Progress Meeting 2  Feb 2009
 MR2 Test Readiness Review (SW)  May 2009
 PM3 Progress Meeting 3  June 2009
 MR3 Acceptance Review  Nov 2009
 Final Presentation September 2009  Dec 2009

Current status

The project was started in August 2008, the contract was signed in September 2008.
After a preliminary design review we made the detailed design and provided the documentation beginning of November 2008.
The Mid-Term Review 1 was held in Vienna Nov 20, 2008 (ref. ART4-MOM-SIA-MTP-A-0001).
After implementation of the Generic RMS software, the Mid-Term Review 2 was held in Vienna May 28, 2009 (ref. ART4-MOM-SIA-MTP-A-0002).
After a validation phase and implementation of the first system for Astrium, the Final Review (MR3) was held in Vienna Dec 1, 2009 (ref. ART4-MOM-SIA-MTP-A-0003).
The project is completed with delivery of the Final Documentation Package.

Status date

Tuesday, January 5, 2010 - 16:47