ES96T
THE UNIVERSITY OF WARWICK
MSc Assignment: 2020
ADVANCED WIRELESS SYSTEMS AND NETWORKS MODULE
Assessment setter (module leader): Dr Subhash Lakshminarayana Assignment Weighting and typical hours work: 60% of the module, 90 hours. Learning outcomes assessed:
• Understand the difference between waterfilling and mercuryfilling power alloca- tions.
• Implement waterfilling and mercuryfilling solutions in a realistic cellular network environment on MATLAB.
• Evaluate the gain achieved by mercuryfilling waterfilling when realistic modula- tion and coding schemes are considered.
Context/Introduction/Background to the assignment: Based on Lectures 9-11 of the module along with further research required for some questions.
Requirements/Task: Please answer all questions (two questions).
Formatting requirements: Electronic reports along with relevant MATLAB/Python
scripts must be submitted.
Submission date/deadline: 10:00 on 1st September 2020. All submissions that miss this deadline will be subject to the normal 5 marks per day penalty, starting at 10:01 on 1st September 2020.
Assessment criteria/mark scheme: Marking is out of 100% and the marks allocated to each question are shown at the end of each question. 80% of marks attributed to technical quality of answers. 20% of marks attributed to presentation.
YOU WILL GET 0 MARKS IF YOU SUBMIT A PUBLICLY AVAILABLE CODE FROM WEBSITES DIRECTLY.
Additional Useful Resources: You will be able to download the pathloss infor- mation and the relevant research papers from the student resources in Moodle.
Feedback format: Each submitted report will be marked electronically and an electronic copy of the feedback will be provided for each report.
ES96T
1. (a)
(b)
Construct a 1km × 1km square 2-dimensional simulation space. Place a base station at the center of simulation space. Then place a single user terminal whose location is chosen according to a uniform random distribution within the cell. Plot the site locations in a single plot with different markers (e.g., triangle for BSs, and circle for UTs). (5 marks)
Assume that the BS transmits at a power of 10 dBW and the noise power is −104 dBm. Consider the 3GPP Urban Micro non-LoS pathloss model (given in lecture notes and also in student resources), and assume a carrier frequency of 2.1 GHz. The channel model must also account for slow fading (shadowing). The gain due to antenna patterns can be ignored. Considering the UT placement of Question 1(a), write a MATLAB script to calculate the signal to noise (SNR) ratio for the UT. In your report, clearly describe the procedure used to calculate the SNR along with the relevant equations.
(10 marks)
Now assume that the total available bandwidth into N subchannels. The channel gain of each subchannel differs in terms of its path loss and shad- owing. Assume that the shadowing gain of each subchannel is indepen- dent and identically distributed.
(25 marks)
(i) Write a MATLAB script to implement the single-user waterfilling algorithm to find the BS optimal subchannel power allocation that maximizes the sum rate.
(ii) In your report, describe the waterfilling algorithm along with the mathematical derivation of how you arrive at the waterfilling solu- tion.
(iii) Tabulate the downlink rate of the UT. Compare the downlink rate with that of apower allocation strategy in which each BS divides the transmit power equally between the available subchannels.
(Total 40 Marks)
Write a technical report to explain optimal power allocation over a set of parallel channels considering adaptive modulation and coding schemes (AMCs). You may refer to reference [1]. In your report, you must clearly describe the drawbacks of waterfilling algorithm when realistic AMCs are taken into account, a generic expression that captures the channel
Question 2 continued overleaf…
(c)
2. (a)
1
ES96T
(b)
capacity under AMCs and the derivation of optimal power allocation using the capacity expression. (25 marks)
(i) In the simulation set up of Question 1, now assume that the BS uses AMCs. Write a MATLAB script to perform optimal power allocation over the channels under AMC. (25 marks)
(ii) Vary the BS transmit power between 1 W to 10 W in steps of 1 W. Plot the resulting sum rate under waterfilling and optimal power allocation. (10 marks)
(Total 60 Marks)
References
[1] W. Guo, S. Wang, and X. Chu, “Capacity expression and power allocation for ar- bitrary modulation and coding rates,” in Proc. IEEE Wireless Communications and Networking Conference (WCNC), 2013, pp. 3294–3299.
END OF ASSIGNMENT
2