Software-defined radio (SDR) is radio in which one or more of the physical functions are implemented with software. The hardware SDR typically replaces are filters, modulators, amplifiers, mixers and other signal processing modules. This means that changing the configuration of an SDR can be done with a software update, while a traditional radio would require hardware changes.

The ability to alter modulation methods, operating frequency and other attributes without additional hardware costs, makes SDR a great tool for experimentation and the development of new communication protocols. SDR is also often used by military and cell phone service providers which require the ability to switch radio protocols in real-time.

While not a necessity, SDR technology is the key to maximizing the potential of adaptive, cognitive and intelligent radio:

• Adaptive radio is a communication system with the ability to monitor and adapt its own performance. SDR provides additional flexibility and as such enables better performance.
• Cognitive radio is aware of which channels in the network are in use, and can dynamically switch to the free channels.
• Intelligent radio is cognitive radio with the addition of machine learning, which enables it to improve over time in how it adapts to its environment.

Red Pitaya SDR Transceiver

Red Pitaya's STEMlab is the perfect board if you are looking to get started with SDR, since all you have to do is to connect your Red Pitaya with the dedicated SDR transceiver module and run the dedicated SDR Transceiver application.

Of course, as a true Swiss Army knife, SDR is just one of the many things a Red Pitaya can do. To see what else is possible with it, click here.

For those looking for to get serious about SDR, look no further than SDRlab which was developed specifically with this use in mind. It comes with two 16 bit ADCs, 50 ohm inputs and 14 bit DACs, 50 ohm outputs. It uses the dual core ARM Cortex A9 offering massively better performance, the Xilinx Zynq 7020 FPGA for more real-time processing capabilities plus an ultra-low phase noise 122.88MHz clock which makes the latest-generation STEMlab more hardware-compatible with HPSDR. 1Gbit Ethernet connectivity has been retained, and RF inputs have been improved in terms of distortion, noise and crosstalk which significantly improves reception and broadens the choice of antenna. SDRlab 122.88-16 retains the original STEMlab form factor so it directly replaces the current platform.

To see Red Pitaya SDR Transceiver in action you can also check out this video by our colleague John (M0JPI).