CME - Channel Measurement Equipment

Objectives

New communication and broadcasting systems use a high level of diversity to increase the service availability. For example time diversity/time interleaving offers a high gain for mobile reception, whereas diversity solves the “flat fading problem” for stationary reception. Combining the technologies requires a detailed characterisation of the propagation characteristics to evaluate the overall gain.


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The channel measurement equipment (CME) is a flexible test receiver designed for multiple applications in the context of statistical analysis of the QoS and coverage of satellite and terrestrial communication systems like:

  • Analysis of the QoS for mobile satellite systems (e.g. DVB-SH, ESDR, SDARS, future broadband systems),
  • Verification of the coverage of terrestrial repeaters,
  • Analysis of antenna subsystems in the field (e.g. antenna diversity gain, comparison of different antennas).

Challenges

The key issue is to provide a flexible measurement equipment that offers a complete tool chain for:

  • LMS-channel characterization
  • Antenna comparison in the field
  • Analysis of antenna diversity effects
  • Network validation and prediction
  • RF-Frontend qualification

Benefits

The main benefits of CME is to offer a product that addresses all aspects of a field strength measurement based field testing campaign, from the recording of the data up to the generation of detailed analysis results, at a reasonable price.

Features

The CME consists of 2 separate hardware units, the "Antenna Assembly" and the "CME Core" which are connected over an optical link.


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Features of the Antenna Assembly:

  • Simultaneous handling of up to 6 antenna signals,
  • Antenna manufacturer independent RF-Input interface,
  • Each of the 6 RF inputs has a high analog bandwidth of 34.67 MHz, supporting center frequencies from VHF to S-Band,
  • Default tuners may be replaced by user specific hardware,
  • 12 V powered equipment.

Features of the CME-Core:

  • Power is measured in bandwidths of 542 kHz, with the number of available power level detectors (16 to 64) depending on the number of simultaneously measured antennas,
  • Power level measurement rate is 2.116 kHz (for each of the up to 64 Sub-Bands),
  • Power levels are recorded together with additional status information (e.g. tuner frequency, GPS data etc) into single file,
  • Snapshot recording of baseband I/Q data (single antenna bandwidth up to 34.67 MHz, multi-antenna bandwidth up to 52 MHz) to hard disk for further analysis, e. g Channel Impulse Response (CIR),
  • Connectivity for GPS Receiver,
  • Comfortable real time GUI displaying power levels, spectrum, C/N and other statistics useful for field testing campaigns,
  • Remote GUI software allowing full control of the CME via secure web access through the internet
  • 12 V powered equipment.

Post-processing features:

  • In-the-field GUI for easy data verification and initial analysis during trials,
  • Detailed post-processing tool chain for advanced signal analysis.

Plan

The major milestones of the project are:

  • Baseline Design Review: October 29th, 2008
  • Midterm Design Review: September 17th, 2009
  • Field testing and validation: November 2009 to February 2010
  • Final Review: July 28th, 2010
  • Final Presentation: September 9th, 2010

Current status

Tasks completed:

  • Definition work
  • System design
  • CMEC hardware design
  • AA hardware design
  • Review of system and hardware design
  • CMEC hardware integration
  • Implementation of system-framework
  • Validation of system-framework
  • Integration of AA hardware (1st prototype)
  • Validation of data processing subsystems (lab tests)
  • First field-validation campaign
  • Design of 2nd generation tuners for AA
  • Integration of 2nd generation tuners for AA
  • Second field-validation campaign
  • Implementation of post-processing features
  • EMC conformance validation

Contacts

Status date

Tuesday, June 26, 2012 - 10:11