What is a software-defined radio modem?
A modem whose signal processing is implemented in reconfigurable logic rather than fixed hardware, so waveform, modulation and coding can be changed after deployment as standards evolve.
PRODUCT · FAMILY 02
Satellite Modem & SDR Platform
An FPGA software-defined modem and signal-processing platform, where the waveform is a configuration rather than a fixed design. A terminal in service for a decade will outlive the specification it shipped with, which is the argument for reconfigurability that unit-cost arithmetic does not capture.
WHAT IT IS
The short version.
A satellite link is long, noisy and geometrically variable. The modem has to acquire and track a signal at low signal-to-noise ratio, correct errors aggressively, and hold the link while the geometry changes underneath it.
Implementing that on FPGA rather than fixed silicon is a deliberate choice. Volumes rarely justify an ASIC, the processing exceeds what a general-purpose processor delivers, and — decisively — waveforms and standards change during a terminal's service life. A design committed to silicon is a design that cannot follow them.
The engineering difficulty is fitting a demanding chain into the device that was budgeted for. Above roughly eighty per cent utilisation the router has little freedom, and timing closure stops being a tool problem and becomes an architecture problem.
DETAIL
Characteristics
| Parameter | Detail |
|---|---|
| Function | Software-defined modem and signal-processing platform |
| Implementation | FPGA, for reconfigurability across a long service life |
| Chain | Filtering, synchronisation, forward error correction and interfaces |
| Configurability | Waveform, rate and coding parameterised |
| Typical markets | Space, defence, satellite communications |
Maturity — silicon-proven, FPGA-validated or RTL stage — is confirmed at enquiry for the specific configuration you need, rather than claimed generically here.
APPLICATIONS
Where it is used.
- Satellite ground terminals — the primary application.
- Defence communications — where waveform agility is an operational requirement.
- Maritime and aeronautical terminals — links with continuously changing geometry.
- Gateway equipment — ground infrastructure serving many terminals.
- Test and simulation — emulating link conditions for validation.
- Research platforms — evaluating waveforms against real channel behaviour.
WHAT YOU RECEIVE
Deliverables and support.
- The platform, configured to the waveform and interface requirements.
- Signal-processing datapath engineering, including per-stage precision analysis.
- Timing closure and resource optimisation against the budgeted device.
- Integration, bring-up and validation against reference waveforms.
Next step
Send the target node, the interface requirements and the integration context. If this is not the right fit, that will be said early rather than discovered at integration.
COMMON QUESTIONS
Questions asked before an evaluation.
Why FPGA rather than ASIC for a satellite modem?
Volumes rarely justify mask cost, the processing exceeds general-purpose processor capability, and terminals in service for a decade will outlive the standards they shipped with — reconfigurability is a product requirement, not a convenience.
What limits how much processing fits?
Device utilisation. Above roughly eighty per cent the router has limited freedom, and timing closure depends on architectural changes — pipelining, restructured clock domains, altered memory access — rather than tool settings.
KEEP READING
Related work.
BUILD WITH FASTSTREAM
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