European Space Agency

Bandwidth-efficient Burst Mode Demodulator

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Objectives

This development project envisages evolving previously developed Burst Mode Demodulator, version 1 (BMD-V1), in order to provide the demodulation of a complete bandwidth of 20 MHz, independent of the configuration of the carriers within that bandwidth. This evolution relies on the design of the first version of Burst Mode Demodulator BMD-V1 equipment for synchronisation and decoding. The design requires a complete re-definition, design and development of the digital filter functions. It aims at the reception of up to 256 carriers, without increase of the equipment cost.



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Economic motivation



  • Positioning on the large telecom operator market requires a drastic reduction of the equipment cost-per-carrier. The proposed bandwidth demodulation approach provides a cost reduction, compared with the BMD-V1 capabilities implementation.

  • Improvement of the equipment technical performance in answer to the Customer's requirement for higher bandwidth efficiency.

  • The product is a key element in Alcatel Space A9780 R2.x multimedia system for which it has been selected after intense evaluation.

  • Alternatively the equipment will complete the ABSp offer to network integrators for both star network configurations as well as for future meshed network configurations.

Technical objectives



A significant cost reduction of the investment cost of Burst Mode Demodulator per carrier is offered to integrators of DVB-RCS compliant systems. This major feature is complemented by additional functionalities and performance improvements.
This feature turns BMD-V2 into a key building block of Alcatel's A9780 R2.x multimedia system.
Other requirements driving this developme

Challenges

The main difference in the digital part of the Burst Mode Demodulator between version 1 and version 2 (=bandwidth-efficient version) is the Channel selection / matched filtering module. While in BMD V1, the Channel Selection and Matched Filtering block is composed of four receive chains, in BMD-V2 the channel selection will allow to select and filter all channels located within the input bandwidth of 20 MHz.

Benefits

Two categories of applications are identified for the burst demodulator :


  • Equipment which are commercially available as stand-alone equipment.

    The BMD-V2 is intended to be sold as an individual building block.

  • Equipment which are an integral part of integrated system architecture.

    This last category is not directly considered as a competition. These equipments are in general not made available on the market as stand-alone units. Provided technical excellence and competitive advantage can be provided by the BMD-V2, these integrated systems supplier could also become potential targets for BMD-V2.
BMD-V2 is equipment which offers a high level of performance in the signal reception, combined with a very high degree of flexibility both in static and dynamic configuration. Its modularity (1U equipment) fits requirements both of MTBF and low cost for small configurations, while keeping a form factor compatible to deployment in large systems. The equipment considered pricing makes it a very cost-effective solution for both integrators and operators.

Features

Besides the adaptation of the filtering algorithms of the BMD-V1.x, the following improvements will also be implemented:



  • The burst demodulator equipment, housed in a 1U drawer, will be able to demodulate up to 256 channels in a 20MHz receive band,

  • Improvement of the Viterbi Decoder performance for short bursts,

  • Improvement of the Turbo Decoder performance,

  • Addition of a redundant Ethernet interface and a separate Management Ethernet interface,

  • Merging of the hardware coprocessor blocks into larger and faster FPGA devices,

  • Remote download of the FPGA image via the industrial PC over the PCI bus,

  • Addition of a redundant ASI output for distribution of received MPEG cells,

  • Addition of a watchdog function for use in a redundant system,

  • Support for the demodulation of bursts when spectrum inversion occurs,

  • Modification of the interface between ARM processor and the Industrial PC: improving the throughput to allow for the increased traffic between the ARM processor and the IPC,

  • Capability to configure the BMD to be able to handle a larger number of different burst types without need for re-configuration of the unit allowing the BMD to be used for adaptive rate coding in the return link,

  • Extension of the current version to extend the compliance with the DVB-RCS standard:


    • Support of QPSK preamble symbols,

    • Support of up to 256 preamble symbols,

  • Redesign of the analogue front-end to follow the latest component evolutions and to improve the phase noise for the low data rate requirements,

  • Support of QPSK as well as BPSK demodulation (although the DVB-RCS standard imposes QPSK as the modulation scheme Alcatel has identified markets where poor link quality and terminal ODU sizing impose BPSK as a modulation scheme),

  • The design of a "Burst Configuration Tool" to configure the Burst Mode De

Plan



















Milestone NameDate
Kick offAugust 2004
Baseline Design Review Meeting (BDR)December 2004
Mid term Review (MTR)July 2005
Prototype Acceptance Review (PAR)October 2005
Final Review 2 (FR)March 2006

Current status

First Industrialised BMD-V2 equipment was ready in June 2006. The Final Review passed successfully and BMD-V2 is available as a product.

Contacts

Status date

Friday, March 7, 2008 - 14:54