Question 3: In relation to MATLAB Simulation - Let us consider a wireless communication system consisting of transmitter, receiver, and an additive white Gaussian noise (AWGN) channel. a) By using a root-raised cosine (RRC) filter 1 with roll-off factor of 0.5 (Refer to Slides 27 29 of Lecture 4 on Baseband Digital Transmission), the following 4-ary symbol stream of length 5 is transmitted: [3,+1,1,3,+3]. Moreover, consider a sampling rate such that there are 16 samples for every symbol duration. Similar to Slide 29 of Lecture 4, plot out the RRC filter output at the transmitter and the RRC filter output at the receiver by assuming a noise-free wireless channel. With the aid of your plots, explain that how ISI is purposely introduced at the transmitter and how ISI is mitigated at the receiver. You must also upload a zipped MATLAB folder with all of your MATLAB codes. [Weight: 15\%] b) From now on, assume that a rectangular pulse waveform is used for each symbol in order to simplify the simulation. Write a MATLAB code to simulate and plot the uncoded 1 https://en.wikipedia.org/wiki/Root-raised-cosine filter bit error rate (BER) versus N0Eb of QPSK and 16-QAM (using Gray mapping) over an additive white Gaussian noise (AWGN) channel. You may refer to the MATLAB code BER_BPSK_sim.m in Moodle for the simulation of the BPSK case. Note that 1) your simulated BER must be down to 104 and 2) you must show the simulated and derived BERs in the PDF report and upload a zipped MATLAB folder with all of your MATLAB codes. The same requirements in 1) and 2) should be met for Questions 3.c and 3.d. [Weight: 15\%]