WinIQSIM is a laboratory environment with all the necessary tools for the analysis and evaluation of digital transmission systems. You can simulate all systems involved in the process of modulation and reception of signals. The program does this by allowing you to define blocks of data sources, configure them and even simulate signal distortion or interference. The instructions are extremely hard to follow though for the none initiated. The developers advise you that "The signals generated with the aid of the R&S® WinIQSIM™ software can be output by the integrated solution in the R&S® SMU (option R&S® SMU-B10) and the R&S® SMIQ (option R&S® SMIQB60) as well as the Arbitrary Waveform Generator R&S® AMIQ. R&S® WinIQSIM™ is provided with these three arbitrary waveform generators free of charge." Therefore, it's worth reiterating that this is only designed for those that know specifically what they are doing with digital wave signals.
Seems like a highly complex and useful program in the right hands but none scientists need not apply.