Performance Analysis of Digital Modulation
Description: Performance Analysis of Digital Modulation Techniques Binary modulation schemes ASK, FSK, PSK n 1, M 2 (Only Two output conditions are possible) Baud is equal to the bit rate M-ary Modulation Techniques QPSK, 8-PSK, 18-PSK, QAM, 16-QAM
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slide1. Performance Analysis of Digital Modulation Techniques<br>
slide3. Binary modulation schemes ASK, FSK, PSK
n = 1,
M = 2 (Only Two output conditions are possible)
Baud is equal to the bit rate<br>
slide4. M-ary Modulation Techniques QPSK, 8-PSK, 18-PSK, QAM, 16-QAM
n > 1
M > 1 (number of output conditions increases)
Minimum bandwidth decreases
Baud rate decreases
Achieves BANDWIDTH COMPRESSION
Less bandwidth is required to propagate a given bit rate
Higher data transmission rates are possible for a given bandwidth<br>
slide5. BANDWIDTH EFFICIENCY Also called as Information density or Spectral efficiency
Used to compare the performance of one digital modulation technique to another<br>
slide6. BANDWIDTH EFFICIENCY “Bandwidth efficiency is the ratio of the transmission bit rate to the minimum bandwidth required for a particular modulation scheme”
Generally normalized to a 1-Hz bandwidth
Indicates the number of bits that can be propagated through a transmission medium for each hertz of bandwidth<br>
slide7. BANDWIDTH EFFICIENCY Bandwidth efficiency can also be given as a percentage by simply multiplying Bη by 100<br>
slide8. Problems<br>
slide9. Example - 1 For an 8-PSK system, operating with an information bit rate of 24 kbps,
Determine
(a) baud
(b) minimum bandwidth
(c) bandwidth efficiency<br>
slide10. Formula To Remember For all Modulation types except FSK
Minimum Bandwidth is given by
Baud rate is given by<br>
slide11. Answer Minimum Bandwidth is given by
Baud rate is given by<br>
slide12. Answer<br>
slide13. Example - 2 For 16-PSK and a transmission system with a 10 kHz bandwidth, determine the maximum bit rate.<br>
slide14. Answer The bandwidth efficiency for 16-PSK is 4
i.e four bits can be propagated through the system for each hertz of bandwidth
Maximum bit rate is simply the product of the bandwidth and the bandwidth efficiency<br>
slide15. Example -3 For the following modulation schemes, construct a table showing the number of bits encoded, number of output conditions, minimum bandwidth, and baud for an information data rate of 12 kbps:
QPSK, 8-PSK, 8-QAM, 16-PSK, and 16-QAM<br>
slide16. To Find<br>
slide17. Answer<br>
slide18. Summary<br>
slide3. Binary modulation schemes ASK, FSK, PSK
n = 1,
M = 2 (Only Two output conditions are possible)
Baud is equal to the bit rate<br>
slide4. M-ary Modulation Techniques QPSK, 8-PSK, 18-PSK, QAM, 16-QAM
n > 1
M > 1 (number of output conditions increases)
Minimum bandwidth decreases
Baud rate decreases
Achieves BANDWIDTH COMPRESSION
Less bandwidth is required to propagate a given bit rate
Higher data transmission rates are possible for a given bandwidth<br>
slide5. BANDWIDTH EFFICIENCY Also called as Information density or Spectral efficiency
Used to compare the performance of one digital modulation technique to another<br>
slide6. BANDWIDTH EFFICIENCY “Bandwidth efficiency is the ratio of the transmission bit rate to the minimum bandwidth required for a particular modulation scheme”
Generally normalized to a 1-Hz bandwidth
Indicates the number of bits that can be propagated through a transmission medium for each hertz of bandwidth<br>
slide7. BANDWIDTH EFFICIENCY Bandwidth efficiency can also be given as a percentage by simply multiplying Bη by 100<br>
slide8. Problems<br>
slide9. Example - 1 For an 8-PSK system, operating with an information bit rate of 24 kbps,
Determine
(a) baud
(b) minimum bandwidth
(c) bandwidth efficiency<br>
slide10. Formula To Remember For all Modulation types except FSK
Minimum Bandwidth is given by
Baud rate is given by<br>
slide11. Answer Minimum Bandwidth is given by
Baud rate is given by<br>
slide12. Answer<br>
slide13. Example - 2 For 16-PSK and a transmission system with a 10 kHz bandwidth, determine the maximum bit rate.<br>
slide14. Answer The bandwidth efficiency for 16-PSK is 4
i.e four bits can be propagated through the system for each hertz of bandwidth
Maximum bit rate is simply the product of the bandwidth and the bandwidth efficiency<br>
slide15. Example -3 For the following modulation schemes, construct a table showing the number of bits encoded, number of output conditions, minimum bandwidth, and baud for an information data rate of 12 kbps:
QPSK, 8-PSK, 8-QAM, 16-PSK, and 16-QAM<br>
slide16. To Find<br>
slide17. Answer<br>
slide18. Summary<br>