- Determine the wavelength for each of the following frequencies
- 702kHz (AM radio)
Wavelength= Speed/ frequency
=
=4.2735m
- 1800MHz (Cellular phone)
Wavelength=
=0.167m
- 2.4GHz (Wi-Fi)
1GHz=1000000000 cycles (Smalling, 2010, p. 456)
2.4=2.4 x 1000000000
=2400000000cycle
=
wavelength=1.25m
- 72GHz (planned 5G band)
=
Wavelength=0.04166m
- What is the EIRP (dBm) for transmitter antenna.
Using EIRP Calculator
Rada Output=150
Cable loss =0
Antenna gain= 9.2
Result= Effective Isotropic Radiated Power 159.2dB
- Maximum possible bit rate without errors
Bandwidth=20MHz
SNR=18Db
Assume the noise is addictive white Gaussian noise (Kramer, 2015, p. 126)
From NY Quist theorem
C= 2 B log2 2n
C is the capacity in bps and B bandwidth in Hz
18=2 x 20 log 20x
= 32
- A 16 QAM modulated signal of bandwidth 10MHz
- What is baud rate of signal?
=10000 divide by 16
=625 bps
- What is the data rate of signal?
N is the number of significant modulation and T is the unit interval
= log2 16 divide by 10
= 32 divide by 10
=3.2
- What is the bandwidth efficiency?
Bandwidth efficiency=
=
=625bps
- Minimum number oscillation points
Data rate= 30Mbps (Smalling, 2010, p. 123)
Bandwidth =10MHz
=
Oscillations = 300 oscillations
- Determine the received power distance between transit and antenna in free space communication.
Received distance= 900 divide by (8dBi +2dBi)
=900 divide by 10
=90m (Adwera, 2013, p. 45)
- What is the loss in dB at a distance of 3km, reference distance 100km at 45dB and path loss index 3.8?
= 1ookm +3 km
= 103km divide by 2
= 51.5 km
Log 51.5 equals to 1.711807
1.711807 x 3.8
=6.5018
- Determine Eb/No
SNR (Db) =Eb x bit rate+10 log base 10
Eb no = 0.4 divide with 0.5
= 0.8
- Determine bit error rate from the diagram
Error rate=0.3
- What is the probability that the received power is less than 2uW?
== log2( 1 + )
= log2 11 = 3.46
= 3.46
Bibliography
Adwera, P., 2013. Networking. s.l.:OLMA Media Group.
Kramer, J., 2015. Communication. s.l.:Adventure Works Press.
Smalling, C., 2010. Radio Signals. s.l.:China Publishing Company.