GNU Radio is a software collection for constructing radios using limited hardware resources.
In essence, GNU Radio creates software-defined radios, or software radios, which allow modulation waveforms to be defined by software. Waveforms are generated via a wideband digital-to-analog converter (DAC) and upconverted from IF to RF, while a receiver employs a wideband Analog to Digital Converter (ADC) to capture all channels of the software radio node. The channel waveform is then demodulated using software on a general-purpose processor.
During receive operations, the objective is to obtain a wideband ADC close to the antenna, generate samples that can be programmed, and then manipulate the samples in software.
The recent release, GNU Radio 2.6, offers the ability to send and receive data at up to 1Mbit/sec using GMSK, as well help for the novel USRP Flex 400 transceiver daughterboards. Additionally, handling of all daughterboards has been unified.
For those interested in wireless networking, the framework is in place to build and experiment with custom MACs. Version 2.6 includes the "null MAC", and a carrier sense MAC is the next logical step.
In summary, GNU Radio is a useful software tool that enables the creation of software-defined radios, making it possible to define the digital modulation schemes used in modern wireless devices as software problems for wireless device designers to solve.
Version 2.8: N/A