HF SDR Testbed (HSTb) is an SDR platform that can facilitate research and development of HF communication systems especially high data rate HF software defined radios. It can also serve as an ideal platform HF channel perturbation analysis, spectrum sensing for HF cognitive radio applications and HF spectrum monitoring for regulatory purposes. HSTb is a combination of Renzym SDR Framework (RSF) software, which runs on the host computer, and HF SDR Transceiver (HST) hardware interfaced with host computer through USB interface. RSF is a complete digital modem software application with more than 15 built-in PSK, QAM and FSK waveforms and powerful graphical analysis capability. On the other hand HST is a high performance, direct conversion, time division duplexed (TDD), HF transceiver which offers 48 KHz of channel bandwidth for high data rate transmission. It also carries a DDS chip for highly agile carrier generation with sub-hertz of tuning resolution making it very useful for frequency hopping and ALE applications. With HSTb, HF system design and analysis cycle can be significantly reduced because it allows you to work directly on your general purpose PC processor (GPP) in higher level languages like C/Python. You can also exploit the computational and visualization capabilities offered by RSF to further facilitate your research and development. HSTb can also be very useful for researchers to obtain real-world HF waveforms at different stages of receiver processing chain. This real world HF-data could be used to test the performance of receiver algorithms.
- More than 15 built-in PSK, QAM and FSK waveforms
- Powerful graphical analysis to aid receiver algorithm development
- Signal recording option every stage of receiver processing chain
- Direct interface to host computer through USB
- Fast frequency hopping capability
- Time division duplexed (TDD) transceiver operation
- Software defined radios
- HF channel perturbation analysis
- Rapid prototyping of high data rate HF radios
- Spectrum sensing for HF cognitive radios
- HF spectrum monitoring for regulatory purposes
At the transmitter end, HF waveforms are generated by Renzym Software Framework (RSF), running on a host computer at a low intermediate frequency (IF). RSF graphical user interface (GUI) will allow the selection of required HF waveform and related parameters. The generated IF waveform is sent to HF SDR Transceiver (HST) through USB interface. HST takes this digital IF signal and performs digital to analog conversion (DAC), frequency up-conversion to the desired carrier frequency in HF band. This signal is further amplified, filtered and transmitted by the HF antenna. HF transceiver is configurable through USB interface and user can control parameters like carrier frequency and output power level from the host computer.
At the receiver end another HST receives the HF signal through its antenna and performs a series of receiver operations like channel filtering, low noise amplification, frequency down-conversion, and analog to digital conversion (ADC). This digital IF signal is sent to the host computer through a USB interface. RSF receives this IF signal and performs filtering and quadrature down-conversion to produce complex baseband (in-phase and quadrature) signals which are further processed for receiver tasks like synchronization and detection. RSF also provides signal recording options at any stage of the receiver processing chain on the computer hard disk. The storage capacity is determined by the hard disk free space and roughly a few hours of recording can be easily made.