At the risk of being slightly OT, I would say that creativeness should really kick off big style when you start your first job. Look at how things are being done and visualize some other methods that will save time and money for the company you work for. I have constructed numerous 'Special boxes' and here is an example;
A special safety ohmmeter was purchased for checking the very low resistance continuity of armament shell fuzes, there were 4 pairs of screened wires. Device failures or rather arming computer shut downs were being caused by a high impedance leak to earth from faulty fuze wire filters that were way out of the resistance range of the safety ohmmeter. The constraints on testing fuzes is something like, a test voltage no greater than 2V at a current no greater than a few milliamps and usually done using a wheatstone bridge. With this restricted power supply it was required to determine if any of the fuze wire insulation was below or above 1M Ohm!
I solved the problem by making for my company a box with a push button MEASURE switch, a TEST switch that selected either o/c or a fixed 1M Ohm resistor and a Red and Green LED. I used a split 3V supply (2 x 1.5V AA cells in series) with 1.5V current limited to the fuze wires and the full 3V for indicators and measuring circuit. The box tested all eight fuze wires at once with a simple press of the button which gave either a RED fail or GREEN pass illumination. It is in fact capable of discriminating 1M Ohms +10k which was far above my expectations for such a simple device.
But it works and it has saved many potential failures in trials etc. that would have wasted $000's
Getting back to the original problem of finding a subject for radio comms, at what level are you thinking of approaching? i.e. applications towards actual RF transmission or perhaps signal generation or even the digital control?
Taking RF for example, maybe it would be nice to design an integrated test box that measured RF Power, SWR, antenna impedance and include a cable reflectometer for finding bad connections in long runs of coaxial cable? Measurement of S parameters with a PC connection for display and print out of a Smiths Chart? It is difficult for me to think about useful items of test gear for the time multiplexed signal traffic etc as it is way out of my own personal field.
Finally! Yes I do apologise for this rather long post, I find most students ask the question of 'What can I build' because all the usual things have been done and they are seeking something new or novel that has not been done before. You are disadvantaged by not actually working in the field where real problems manifest themselves and ask for something special to assist. Remember the old saying: "Necessity is the The Mother of Invention". If in desperation you have to select something as simple as an SWR meter then try to think of a novel approach to it that has not been done before, either in measurement technique or display. Most importantly, whatever you do, ensure that you complete a very comprehensive literature pack with circuits, construction sketches, test/calibration results, how it works and even your first ideas! I think presentation of your work rather than the actual device itself will give you most bonus points here. Good Luck with your project and attaining your qualifications!
Les