Reference no: EM133196133

Question 1.

a) Give your answers to 3 significant figures. Show your working to obtain full marks.

i) Calculate the received power per square metre from a GPS transmitter that is 20 000 km above the surface of the Earth and transmitting at a power of 35 W at a GPS receiver on the surface of the Earth.

ii) If the antenna in (i) is 10 cm x 10 cm in size calculate the received power in Watts.

Assume the power transmitted by the GPS transmitter is fully received by the GPS receiver.

b) A mobile user who is 200 m from a particular base station has a received signal power of 2 mW. Use the inverse-fourth power relationship to find an approximation for the received signal power for a mobile user who is 800 m from the same base station.

Question 2.

Pick two of the ten heuristics for heuristic evaluation itemised in Block 2 Part 5, Section 5.4 (excluding heuristics 8 and 10). For each of the two heuristics, select an interface of some digital product with which you have experience that fails that heuristic. Describe concretely the way in which it fails, and suggest a concrete way to improve the design to address this failure. (You should not use an interface already analysed, or used as an example, in the module.)

Screenshots are highly welcome

It is acceptable to use screenshots from any source, provided the source is referenced.