The W1902EP/ET Digital Modem Library is a simulation add-on for SystemVue that enables transmit, receive, and Bit-Error-Rate (BER) analysis for 40 digital modulation formats used in satellite, military and commercial wireless communication systems. Additionally, the W1902 provides framing, Direct-Sequence Spread Spectrum (DSSS), and reference receiver designs for 25 of the linear modulation formats. The library enables higher design productivity, reduces verification effort, and supports a model-based design approach across the entire communications design cycle – from algorithm to implementation to hardware verification – using wideband test equipment.
Productivity and Flexibility for A/D Applications
As military and satellite communications networks are being upgraded to newer high-capacity and low-latency formats, many communications designers continue to invest project overhead time to maintain personal simulation blocksets and tools.
- The W1902 Digital Modem library reduces modeling overhead and streamlines verification by providing a reliable, commercial off-the-shelf (COTS) reference for common modulation formats.
- The W1902 also connects easily to test equipment and other RF design tools, which enables a higher level of system simulation accuracy needed for RF/FPGA co-design, digital pre-distortion, test equipment support for today’s wider bandwidths.
- SystemVue allows for easy import of intellectual property in C++, MATLAB, and HDL formats, allowing the additional modeling details required by classified, secure, and academic research applications to be easily accommodated.
- The W1902 is especially recommended for “software-defined radio” (SDR) and “cognitive radio” (CR) studies
Together with EDA-friendly licensing that promotes greater design re-use and distributed collaboration, the W1902 Digital Modem library provides the productivity benefits of a supported COTS environment, while preserving the flexibility needed for custom/secure design teams.
Who should use the SystemVue Digital Modem Library?
System-level architects, baseband algorithm designers, and RF component designers can use the W1902 Digital Modem library to perform early R&D validation of communication system architectures, components, and DSP algorithms. The W1902 also provides a convenient modeling platform for custom applications and proprietary communications links.
The SystemVue environment is also scriptable, links to RF design tools such as Keysight ADS, and connects to high-performance test equipment, providing both flexibility and consistency across a full product lifecycle.
Key Applications
- Satellite communications, including ground-space, space-space, and deep-space
- Military communications and secure backhaul
- Academic research
- Extended test equipment support for specialized modulation formats
- Component validation
Key Benefits
- Higher productivity, through a trusted IP reference on an open modeling environment
- Lower project overhead, scripting, verification, and NRE
- Faster time to deployment, through superior RF-DSP co-design in SystemVue
What is included?
Reference Transmitter |
Reference Receiver |
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- Modulation for 25 modulation formats (note 1)
- Oversampling and Filtering (note 1)
- Framing (user-definable length, modulation, data)
- Guard Interval
- Idle Interval
- Preamble
- Payload
- Waveform and data I/O
- Input data from simulation or file I/O
- Output complex modulated waveform to simulation, file I/O or test equipment
- Additional outputs for framing, preamble and other functions
- Direct Sequence Spread Spectrum (DSSS) spreading (user-definable)
- Coding support
- Built-in LDPC coding
- Users are free to add other external algorithms for coding and error correction using C++, MATLAB, and HDL formats
- Impairments
- Users can add or sweep a wide range of RF impairments and channel models outside the Digital Modem source
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- De-modulation for 25 modulation formats (notes 2,3)
- Filtering, Synchronization, and Re-sampling (notes 2,3)
- Corrections applied:
- Carrier Frequency offset (e.g. – Doppler)
- IQ phase rotation
- IQ imbalance
- AGC re-normalization
- Adaptive Equalization
- Linear (LE) and Decision Feedback (DFE)
- Adaptive Algorithms (RLS, LMS, RLS/LMS)
- Fractional-Space Equalizer (FSE) for both LE and DFE
- MMSE-DFE (fast computation DFE)
- Maximum Likelihood Sequence Detector (MLSE)
- Rake combiner for DSSS
- Frame synchronization
- correlation
- differential correlation algorithms
- Carrier frequency synchronization and frequency tracking algorithm using PLL
- Channel decoding
- LDPC decoding
- Soft de-mapper
- Waveform and data I/O
- Input complex modulated waveform from simulation, file I/O or test equipment
- Additional inputs for framing, preamble, etc.
- Output data bits, constellation
- Measurements and pre-configured templates
- BER vs. Eb/N0 or SNR sweeps
- EVM
- System-level verification
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Notes:
- 40 total modulation formats are supported outside the reference transmitter source. Also, some raw modulation features (source only) are available using the “DigitalMod” source included in the core SystemVue environment. This free source does not provide framing, DSSS or demodulation.
- The W1902 supports 40 total demodulation formats. The reference receiver supports 25 of them.
- Some dynamic visualization features are available using the Keysight 89600 VSA software, option AYA. The 89600 VSA does not provide framing, DSSS or demodulated data output.
Formats supported with Framing, DSSS, and full TX/RX reference for BER
16-QAM
32-QAM
64-QAM
128-QAM
256-QAM
512-QAM
1024-QAM
2048-QAM
4096-QAM |
BPSK DBPSK
QPSK pi/2 DBPSK
8-PSK DQPSK
16-PSK pi/4 DQPSK
16-APSK D8PSK
32-APSK pi/8 D8PSK
Custom APSK pi/4-CQPSK
Star 16-QAM
Star 32-QAM |
Additional formats supported for simple modulation/demodulation
OQPSK
SOQPSK-TG
SOQPSK-MIL*
IJF-OQPSK
FQPSK
EFQPSK
CQPSK
EDGE-8PSK |
2FSK
4FSK
8FSK
16FSK
MSK
GMSK
M-ary CPM
Multi-h CPM* |
*Some limitations apply
Figure 1. The W1902 Digital Modem library supports framing and spread spectrum functions for 34 essential modulation/demodulation formats, allowing communications designers to quickly analyze BER performance of satellite and military radio links.
Figure 2. In this example, the W1902 library is used to analyze a 512 QAM communications link having amplifier nonlinearities, finite ADC resolution, AWGN receiver noise, and simple channel effects. For enhanced realism, the same scripting can also work with RF test equipment in the verification loop.
Configuration
The W1902 Digital Modem Library can be added as an option to any W146x-series SystemVue environment or bundle.
Complementary Keysight software (such as Keysight I/O Libraries, Command Expert, and 89600 VSA software) are often used to connect SystemVue to Keysight test equipment families, such as AWGs, digitizers, RF sources, RF analyzers, and others.
For More Information
Please directly contact your local Keysight EEsof EDA sales representative to inquire about this library and its associated training and consulting services.