This document contains summaries of 8 questions related to wireless networks and communication. Each question summary provides an overview of the concepts and steps discussed in the answer. Key topics covered include modulation techniques, error detection methods like cyclic redundancy check and frame check sequence, spread spectrum techniques, and cellular network cell structures. References are provided at the end related to wireless communications research.

1. Wireless Networks &
Communication

2. Table of Contents
Answer of Question-1............................................................................................................... 3
Answer of Question-2............................................................................................................... 5
Answer of Question-3............................................................................................................... 6
Answer of Question-4............................................................................................................... 8
Answer of Question-................................................................................................................. 9
Answer of Question-6............................................................................................................. 10
Answer of Question-7............................................................................................................. 12
Answer of Question-8............................................................................................................. 12
References ............................................................................................................................... 13

3. Answer of Question-1
a) The presentation of 2-Level ASK Modulation for 110101 is shown below:
b) The presentation of 2-Level FSK Modulation for 110101 is shown below:
c) The presentation of 2-Level PSK Modulation for 110101 is shown below:

4. d) The presentation of DPSK Modulation for 110101 is shown below:
e) The presentation of 4-Level ASK Modulation for 110101 is shown below:
f) The presentation of 4-Level PSK Modulation for 110101 is shown below:

5. g) The presentation of 8-Level ASK Modulation for 110101 is shown below:
Answer of Question-2
Multiple Frequency Shift Keying is applied in this answer for the frequency
assignment of the components. Thus, some parameters are given based on which the
operation will be performed. The Frequency of the carrier signal is given by 1000KHz
and the diff frequency is provided by 50KHz with signal level by 16. It means, there
are 16 possible combinations of the frequency components and each component will
contain 4 binary bit with sequential combinations (Li, et al., 2019).
So, the frequency components are shown below:
0000 0001 0010 0011 0100 0101 0110 0111
1000 1001 1010 1011 1100 1101 1110 1111
The assignment of the frequency of each componentcan be computedbythe following
equation:
fi=fc+(2×i-1-M)×fd
Using this equation, the frequency for each componentis computedand shown below:
0000250 KHz 0001350 KHz 0010450 KHz 0011550 KHz
0100650 KHz 0101750 KHz 0110850 KHz 0111950 KHz
10001050 KHz 10011150 KHz 10101250 KHz 10111350 KHz
11001450 KHz 11011550 KHz 11101650 KHz 11111750 KHz

6. Answer of Question-3
The input message signal is provided in the instruction is shown below. The signal is
with the magnitude of 0.5 V and the time period with 59 seconds approx. and so the
frequency is about 0.017 Hz approx. This signal is used for the modulation purpose
with the implication of the carrier signal and that will be shown in the respective
section.
The steps of the Analog Modulation and the Frequency modulation will be
demonstrated below (Zhou, 2016).
a. Analog Modulation:
The steps for the Analog modulation are shown below.
i. For the first step, the message signal is taken as the input to the modulator
and the modulation will be done on behalf of this.
ii. For the second step, the carrier signal is taken as the input of the modulator.
iii. These two signals will be fed to the modulator and the message signal will
be subjectedto the modulationand thus the outcome willbe obtained at the
next step (Rodríguez-Fernández & González-Prelcic, 2019).

7. iv. Finally, the Analog modulated signal is obtained and the pulse is shown
below:
So, with help of the carrier signal and the message signal are taken into the modulator
where the modulation is done on the basis of the two and finally generates the
modulated waveform.
b. Frequency Modulation:
The steps for the Frequency modulation are shown below.
i. For the first step, the message signal is taken as the input to the modulator
and the modulation will be done on behalf of this.
ii. For the second step, the carrier signal is taken as the input of the modulator.

8. iii. These two signals will be fed to the modulator and the message signal will
be subjectedto the modulationand thus the outcome willbe obtained at the
next step (Rodríguez-Fernández & González-Prelcic, 2019).
iv. Finally, the Frequency modulated signal is obtained and the pulse is shown
below:
So, with help of the carrier signal and the message signal are taken into the modulator
where the modulation is done on the basis of the two and finally generates the
modulated waveform.
Answer of Question-4
QuadratureAmplitudeModulationisthe typeof Amplitudemodulationand this may
contain different phases and amplitude divisions. While modulation is done, there
may be some error will be generated and most of those error cannot be identified
properly. So, there will be some other means or measures to be taken so that the error
can be identified and visualize. The technique to do this is called the constellation
diagram. In this case, the constellation diagram will be shown on behalf of the 16-
QAM, that is there will be 16 phases (Meng, et al., 2019). Here, the 16-QAM will be
shown which contains or the constellation will be sown for the 4-different phases and
different amplitude divisions. The constellation diagram is shown below:

9. The above figure shows the constellation diagram for 16-QAM with the satisfactory
conditions as stated in the instruction. The states of the modulated segments are
denoted by the binary numbers for the identification.
Answer of Question-
Cyclic Redundancy Check is the process used to determine the error incorporated
with the data that is being transferred or stored in the network storage or the hard
drive. The technique to send the data is that, the data is first arrived at the transmitting
end and there, using the Cyclic Redundancy Check process, the division method s
applied and s the remainder bit (“0” or “1”) is appended with the data. This newly
generated data will be transferred to the receiver section and there the data is finally
received. At the receiving end, again the division process with the implication of
Cyclic Redundancy Check is applied and the similar action is taken to find out the
remainder by division process (D’amico, et al., 2019). If the remainder is found at the
receiving end is same as the transmitting end, then the data is considered as the error
free data and then it will be accepted. For the either case, the data will be rejected as
by the algorithm of Cyclic Redundancy Check, the error data will be rejected from the
end. The entre process flow is shown below:

10. The process of Cyclic Redundancy Check is demonstrated above picture which is
alreadydescribed.The data from the sender sectionwill be transferred to the receiving
section along with the remainder bit or more sophistically it can be said as the CRC
bit (Zhou, 2016).
Answer of Question-6
Frame Check Sequence is used for checking the data while transmission. In this case,
the data bit sequence will be transferred to the data frame and this data frame will be
transferred from the transmitting end to receiving end. The technique of the Frame
Check Sequence is nearly same as the Cyclic Redundancy Check method but here the
frame will be checked. The data frame contains the address of the transmitting end
the receiving end and the data itself. The data will be checked using the pattern bit
and by the division method (Zhou, 2016) . At the transmitting end, the division
method is applied and s the remainder bit (“0” or “1”) is appended with the data. This
newly generated data will be transferred to the receiver section and there the data is
finally received. At the receiving end, again the division process with the implication
of Frame Check Sequence is applied and the similar action is taken to find out the
remainder by division process. If the remainder is found at the receiving end is same
as the transmitting end, then the data is considered as the error free data and then it
will be accepted. For the either case, the data will be rejected as by the algorithm of
Frame Check Sequence, the error data will be rejected from the end (Li, et al., 2019).
Frame Check Sequence process is executed both at the transmitting end and the
receiving end to check for the remainder bit. In this computation, the message bit is
provided by “111010110” with the associated pattern “101110” along with the weight
of is computed by 15. So, the computation for the Frame Check Sequence at both the
ends are shown below:

11. Data Transmitting End:
1 1 0 0 0 0 0 0 0 0
101110 1110101100000000
101110
111001
101110
100111
101110
110010
101110
101000
101110
100000
101110
1101000 Remainder
Data Receiving End:
101110 111010111101000
101110
111001
101110
100111
101110
110011
101110
101011
101110
110000
101110
110100 Remainder

12. In both two cases, the remainder is same (“0”) and so the data willbe accepted as there
is no error.
Answer of Question-7
Direct Sequence Spread Spectrum uses the logical XOR method for the generation of
the sequence with the successive input of the message sequence and the pseudo noise
sequencewhich may be generated locally.Here, the Direct Sequence Spread Spectrum
will bedetermined for the input messagesequence101 and the pseudonoisesequence
011011010110. The outcome is shown below in form of calculation and graphical
representation (D’amico, et al., 2019).
i. Calculation
101⨁ 011011010110
=000000000101⨁ 011011010110
= 11011010011
ii. Graphical representation
Answer of Question-8
In cellular network or communication, there are different types of cells are there with
different shapes. Among those, the hexagonal cell is used widely as compared to the
square or circular cell as those are not appropriate as the hexagonal cells. The
hexagonal cells can tie together up without creating the unused space and the
overlapping space which the circular cell faces. On the other hand, the distance from
the centre to all the points to the periphery are same for hexagonal cell but for the
square it is not. As the hexagonal cell contains all the flavour of the advantages of the
radiation and the information exchange, hexagonal cell is favouring the most
compared t the other two (Meng, et al., 2019).

13. References
D’amico,A.A.,Morelli,M. & Moretti,M., 2019. A Novel Scheme forCP-LengthDetectionandInitial
Synchronizationforthe LTE Downlink. IEEETransactionson WirelessCommunications, 18(10),pp.
4668 - 4678.
Li, X.,Pan,T., Alim,M.A. & Thai, M. T., 2019. Resource AllocationinHighlyDynamicDevice-to-
Device Communication:AnAdaptiveSetMulti-CoverApproach. IEEETransactionson Wireless
Communications, 18(10),pp.4607 - 4619.
Meng,X. et al.,2019. Closed-FormDelay-OptimalComputation OffloadinginMobile Edge
ComputingSystems. IEEETransactionson WirelessCommunications, 18(10),pp.4653 - 4667.
Rodríguez-Fernández,J.& González-Prelcic,N.,2019. Channel EstimationforHybridmmWave MIMO
SystemsWithCFOUncertainties. IEEETransactionson Wireless Communications, 18(10),pp. 4636 -
4652.
Zhou,L. F., 2016. “Experimental researchof alignmenterrorcorrectionbyasphericmirrorbasedon
the functionof imagingquality. Int.Journalon Wireless Com.