As part of its advance toward enabling software defined microwave systems, Teledyne e2v is previewing a prototype optical link technology July 19th in Grenoble, which might soon make obsolete legacy copper data links in digital radio system design.

Newsworthy pointers

• Streaming sample, control & configuration data, as well as reference clock and synchronization signals via optical fibers simplifies signal distribution and reduces cable mass in complex digital radio designs
• Eliminates all copper signal wiring in future radios offering increased architectural flexibility while reducing crosstalk and inter-channel interference
• Concept substantiates a separation of front-end analog design from backend digital signal processing heralding the arrival of fully digital antennas

Highlighting the advantages of this initiative, Nicolas Chantier, Strategic Marketing Director stated: 

"Our optical data link research marks a moment in time when the radio’s front-end can finally be decoupled from the advanced backend digital data processing of software defined radios (SDRs). In so doing, designers gain implementation flexibility, enhanced digital beam forming capabilities and several extra design freedoms.”

About modern high-speed data interfacing

Two copper-based serial interfaces predominate. They are the industry standard JESD204 link and the alternative, license free ESIstream from Teledyne e2v.

Data interfacing in sampled systems requires considered implementation. Perhaps the largest challenge, particularly in highly parallelized, multi-channel (i.e., electronically steered beam) systems, is ensuring that data samples are accurately time aligned. Time alignment ensures signal phase information and thus, the critical spatial information embedded within the received signals is preserved.

Cross-channel synchronization is further complicated by metastability – an inherent, pseudo-random behavior of digital systems. It can be mitigated through careful design. 

Despite optical data links powering the modern global broadband backbone, to date there have been few efforts to replace traditional copper in radio front-end design.

ODH benefits

The move to optical data link technology provides multiple system benefits including:

• Lossless, long-range transmission
• Freedom of separation between front-end receive and signal processing systems
• Zero EMI lowers crosstalk and signal interferers
• Weight reduction

Technology availability

The ODH system is at the proof-of-concept stage. Teledyne e2v have extensively simulated the digital design of the control methods and is currently finalizing the first hardware implementation. The company plans several updates throughout this and next year as the project progresses.

Click here for the White Paper.