MATLAB and Simulink connect to the USRP™ family of software-defined radios (SDR) to provide a radio-in-the-loop design and modeling environment. With the support package, Communications System Toolbox, and a USRP radio you can design and verify practical SDR systems starting with Release 2011a of MATLAB and Simulink.
Using System objects in MATLAB or blocks in Simulink, a user can configure parameters such as center frequency, gain, and interpolation or decimation rates. The user can transmit signals from MATLAB or Simulink by streaming data to USRP devices via the UHD interface. Similarly, the user can receive over-the-air signals from a USRP device and process the streaming data using MATLAB System objects or Simulink blocks.
The package supports Windows, Linux, and Mac platforms and can be downloaded from the MathWorks web site at http://www.mathworks.com/discovery/sdr/usrp.html