首页
网站开发
桌面应用
管理软件
微信开发
App开发
嵌入式软件
工具软件
数据采集与分析
其他
首页
>
> 详细
CAN202代写、代做MATLAB编程设计
项目预算:
开发周期:
发布时间:
要求地区:
Page 1 of 3
CAN202 Analogue and Digital Communications I Coursework AY202324
Instructions:
1. 100 marks are available from this coursework (20% towards the total mark of CAN202)
2. Please submit one PDF file that contains your answers and CORRECT student ID.
3. Release date of the coursework: Friday 5
th April 2024.
4. Due date of the coursework: 23:59, Monday 6
th May 2024.
5. There are 11 questions in total. Answer ALL questions.
6. If asked, support your answer with figures. Make sure the figures are READABLE.
7. Append all necessary codes at the end of the to-be-submitted PDF or at the
corresponding answers.
8. No generative AI may be used when completing the coursework.
9. Learning outcome accessed: A, B, E.
10. The usual late-submission policy may apply (e.g., 5 marks deduction per working day).
The questions begin:
Figure 1 shows a periodic triangular wave 𝑠(𝑡), where the period is 𝑇 seconds.
Figure 1 A periodic triangular wave
Q1 Show sufficient steps to verify that a Fourier series representation of 𝑠(𝑡) in Figure 1 is
𝑠(𝑡) = ∑ 𝐶𝑛𝑒
𝑗2𝜋𝑛𝑡
𝑇
∞
𝑛=−∞
,
where 𝐶0 = 0 and 𝐶𝑛 =
2𝐴(𝑒
−𝑗𝜋𝑛−1)
𝜋2𝑛2
. (Hint: It may be easier to find the Fourier series
representation of 𝑑𝑠(𝑡)
𝑑𝑡
= ∑ 𝐵𝑛𝑒
𝑗2𝜋𝑛𝑡
∞ 𝑇 𝑛=−∞ and then find 𝐶𝑛 =
𝑇
𝑗2𝜋𝑛
𝐵𝑛 , where the latter
comes from a property of Fourier series that links the Fourier series coefficients
between a periodic signal and its integration) (10 marks)
Q2 Rewrite the Fourier series of 𝑠(𝑡) in the following form, i.e.,
𝑠(𝑡) = ∑ 𝐷𝑛 cos (
2𝜋𝑛𝑡
𝑇
+ 𝜃𝑛) ,
∞
𝑛=0
where you need to determine 𝐷𝑛 and 𝜃𝑛. (5 marks)
Then, suppose there is a bandlimited modulating signal 𝑚(𝑡) whose bandwidth is 0.2
𝑇
Hz.
Plot the frequency spectrum of 𝑚(𝑡)𝑠(𝑡). You may assume that the frequency spectrum
of 𝑚(𝑡) has the shape in Figure 2. (10 marks)
Page 2 of 3
Figure 2 An illustration of the frequency spectrum of 𝑚(𝑡)
Q3 We can generate a double-sideband suppressed carrier amplitude modulated (DSB-SC
AM) signal based on 𝑚(𝑡) × 𝑠(𝑡) and an appropriate bandpass filter (BPF), where the
carrier frequency is 𝑇
−1 Hz. Draw a diagram that realizes such a DSB-SC AM scheme,
where the functions of all components in the diagram must be specified. (5 marks)
In the second part of the assignment, we will scramble the frequency components of a piece
of soundtrack that somehow disguise the sound, and then we descramble and restore the
soundtrack. We will use the soundtrack in “handel.mat”. By typing the command “load
handel” in MATLAB, you will find two variables in the workspace, i.e., “y” and “Fs”, where
“y” contains samples of the soundtrack and “Fs” specifies the sampling frequency in Hz that
gives rise to the samples in “y”. We may treat “Fs/2” as the bandwidth of the soundtrack.
After loading “handel”, we may play the soundtrack using the following command:
“player = audioplayer(y, Fs); play(player);”
If your loudspeaker works, you should hear “hallelujah, hallelujah, …”.
Figure 3 shows a simple scrambler that scrambles the frequency spectrum of “y” and give
rise to “z”. Figure 4 shows a descrambler that would, ideally, restore the frequency
spectrum of “y” from “z”.
Figure 3 A scrambler
Figure 4 A descrambler for the scrambler in Figure 3
Q4 In Figure 3, assume 𝑦(𝑡) is bandlimited to Fs/2 Hz. Sketch the frequency spectrum of
𝑧(𝑡). (10 marks)
Q5 Show with illustrating figures that the system in Figure 4 can restore 𝑦(𝑡) from 𝑧(𝑡).
(10 marks)
Page 3 of 3
We can demonstrate the above in MATLAB, where we will scramble “y” and descramble “z”.
Specifically, we calculate the discrete Fourier transform (DFT) of various discrete-time
signals in the above scrambler/descrambler system and observe the frequency spectra. We
will also play the soundtrack of 𝑧(𝑡) in Figure 3 and 𝑦(𝑡) in Figure 4 for verification. The DFT
can be calculated using the “fft” function in MATLAB.
The “fft(y)” returns frequency domain samples from frequency zero to Fs − 𝑇0
−1
, where Fs is
the sampling frequency of “y” and 𝑇0 is the duration of the time-domain signal. Because the
DFT samples are periodic, one may use the command “fftshift( fft( y ) )” to swap the two
halves of “fft(y)”, such that the zero-frequency component appears at the center of the
vector returned by “fftshift( fft( y ) )”.
One thing to note is that the DFT calculation is related to the sampling frequency. In Figure
3, we need to multiply 𝑦(𝑡) with a carrier signal that has a frequency of Fs, and the resulting
signal 𝑦1(𝑡) would have the largest bandwidth (counting from frequency zero) among all
signals in the systems of Figures 3 and 4. To use DFT correctly for 𝑦1(𝑡), we need to have a
sampling frequency that is at least twice as much as the bandwidth of 𝑦1(𝑡) (again, counting
from frequency zero). However, the soundtrack from “handel” is not sampled at a
sufficiently high frequency, so we need to upsample the soundtrack first. The upsampling
can be done using the command “resample(y, Fs_new,Fs)”, where Fs_new is the new
sampling frequency that is sufficiently large.
Please answer the following questions based on MATLAB programming.
Q6 Load “handel” in MATLAB and play the soundtrack. Calculate the DFT of the soundtrack
samples using “fft”. Then, plot the discrete frequency spectrum as calculated from the
DFT, where you should use the command “fftshift” to rearrange the results from “fft”.
Label the frequency values of the samples from the frequency spectrum. (5 marks)
Q7 Perform upsampling to the vector “y” from “handel”, where the new sampling
frequency is Fs × 2. Play the upsampled soundtrack and make sure that it sounds the
same as that in Q6. (5 marks)
Q8 Generate samples of 𝑦1(𝑡) (refer to Figure 3), where you may need to sample a correct
carrier signal with the correct sampling frequency. Plot the DFT of 𝑦1(𝑡) in MATLAB and
label the frequencies; explain whether this plot meets your expectation. (10 marks)
Q9 Perform lowpass filtering to the samples of 𝑦1(𝑡) and obtain samples of 𝑦2(𝑡). The
sampled impulse response of the lowpass filter may come from a truncated sinc pulse
that approximates an ideal lowpass filter with a bandwidth of Fs. You may then use
“conv” to perform convolution (or, equivalently, the filtering operation in the timedomain). Plot the DFT of 𝑦2(𝑡). (10 marks)
Q10 Following Figure 3, obtain samples of the scrambled soundtrack 𝑧(𝑡) in MATLAB.
Plot the DFT of 𝑧(𝑡) and play the time-domain samples. Comment on what you hear
from 𝑧(𝑡). (10 marks)
Q11 Following Figure 4, descramble 𝑧(𝑡) and obtain 𝑦′(𝑡). Plot the DFT of 𝑦′(𝑡) in
MATLAB. Also, play the samples of 𝑦′(𝑡). Comment your observations. (10 marks)
End of Coursework
软件开发、广告设计客服
QQ:99515681
邮箱:99515681@qq.com
工作时间:8:00-23:00
微信:codinghelp
热点项目
更多
cis432代做、代写python/java程...
2024-05-04
eeen3007j代写、c++程序设计代...
2024-05-04
代写data程序、代做c/c++, jav...
2024-05-04
comp2006代做、代写c++程序语言
2024-05-04
comp26020代做、java/c++设计编...
2024-05-04
csci251 advanced programming...
2024-05-03
cs 6290: high-performance co...
2024-05-03
assignment 2: executing and ...
2024-05-03
ecse427/comp310 programmin...
2024-05-03
cs 452 (fall 22): operating...
2024-05-03
comp9414 23t2 assignment 2 ...
2024-05-03
dpst1091 23t1 assignment 2 ...
2024-05-03
program代做、代写python设计编...
2024-05-03
热点标签
finm8007
comp2006
comp26020
comp1721
eeen3007j
cis432
csci251
comp5125m
com398sust
32022
mth6158
comp328
finn41615
2024
mec302
mgmt3004
mgt7158
com160
as.640.440
econ3016
finm7405
econ7021
fin600
infs4205/7205
mktg2510-
f27sb
csse2310/csse7231
rv32i
eecs 113
comp1117b
cs 412
comp 315
econ7300
comp2017
ecs 116
fit5046
com6511
comp30024
acs341
econ1020
isys3014
acc408
comp1047
csc 256
cs 6347
finm7008
comp34212
csmde21
estr2520
comp285/comp220
mds5130/iba6205
finc6010
is3s665
busi2194
125.785
iom209
msin0041
econ339
cmt218
mast10007
comp5349
ecx2953/ecx5953
bios706
comp3310
mth6150
comp30027
comp20005
eec286
busi2211
bff2401
fnce90046
visu2001
mang6554
finc6001
125785
data423-24s1
engi 1331
fint2100
(520|600).666
can202
cs 61b
mast20029
info20003
stat512
econ3208
cmpsc311
engg1340
ecmt1010
fit5216
basc0003
ee3121
acct2002
comp5313
busi2131
ise529
elec372/472
csit940/csit440
cenv6141
comp3027/comp3927
ftec5580
comp1433
msci223
mark203
en3098
eden1000
ece6483
econ4410
mats16302
cs 6476
com6521
comp222
comp3211
comp10002
csc1002
chc6186
cs 161
comp27112
comp282
swen20003
comm1190
elec9764
acfi3308
acct7101
fin6035
comp2048
geog0163
comp2013
coen 146
dts101tc
sehh2042
comp30023
comp4880/8880
cs 455
07
stat0045.
fil-30023
celen085
psyc40005
math40082
are271
comp9311
ee5311
imse2113
comp 2322
acct2102
fnd109
int102
is3s664
is6153
data4000
accfin5034
fit5212
cs536-s24
fit5225
ecos3006
mes202tc
finc5001
stat3061
csc171
cs1b
7ssmm712
bu.450.760
cs170
comp3411
swen90004
cpt206
comp5313/comp4313—large
bl5611
kxo206
comp532
elec207
kxo151
cs 2820
cpt108
math2319
dts204tc
qm222
comp2511
ccs599
infs1001
mat2355
eeee4123
25721
ifn647
pols0010
hpm 573
qbus6860
comp9417
csci 1100
stat0023
cse340
comp2003j
cs 2550
cs360
fin 3080
ierg 4080
cs6238
cit 594
finm7406
hw6
联系我们
- QQ: 9951568
© 2021
www.rj363.com
软件定制开发网!