ICT Projects: RESULT AND DISCUSSION of WCDMA SYSTEM WITH DIFFERENT CHANNEL CONDITIONS

Saturday, April 28, 2012

RESULT AND DISCUSSION of WCDMA SYSTEM WITH DIFFERENT CHANNEL CONDITIONS

PERFORMANCE ANALYSIS ON MODULATION TECHNIQUES IN

WCDMA SYSTEM WITH DIFFERENT CHANNEL CONDITIONS

RESULT AND DISCUSSION

5.1     Simulation results

Based on data generated by computer simulation of W-CDMA models, relationship for multiple rays using QPSK and QAM modulation techniques between BER as a function of the following parameters are obtained. They are:

1. Bit Error Rate (BER) versus Signal-to-Noise ratio (SNR) in AWGN channel for QPSK modulation technique.

2. BER versus SNR in AWGN channel for 16-QAM modulation scheme.

3. BER versus SNR in AWGN and multipath Rayleigh fading channel with Doppler shift (60kmph and 120kmph) for QPSK modulation technique.

4. BER versus SNR in AWGN and multipath Rayleigh fading channel with Doppler shift (60kmph and 120kmph) for 16-QAM modulation scheme.

5. BER versus SNR to compare between AWGN channel and multipath Raleigh fading channel for different number of user for QPSK modulation technique.

6. BER versus SNR to compare between AWGN channel and multipath Raleigh fading channel for different number of user for 16-QAM modulation technique.

The simulation is followed by using m file. In this approach, the simulation is successfully done using QPSK modulation technique. The desired BER graphs are obtained for simulation in AWGN channel.

Also, satisfactory result is obtained when the system is simulated in AWGN and multipath Fading channel subjected to Doppler Shift with mobile terminal moving at 60kmph and 120kmph. However, the simulation does not yield the desired outcome when 16-QAM is employed as the modulation technique in the W-CDMA system. The results of these two approaches are discussed in this chapter.

5.1.1 Performance Analysis of QPSK modulation technique of WCDMA in AWGN

In this simulation, the BERs are obtained by varying the values of EbNo in the range of 0 to 10 when the number of user is 1. The iteration is done 1000 times where the total number of data transmitted is 200,000.

Table 5.1:       Simulation result for evaluation on BER vs. SNR for 2-ray AWGN channel for 1 user when the number of data is 200,000

Signal to noise ratio

(EbNo)

No. of Error

Bit Error Rate (BER)

0

15702

7.851000e-002

1

11223

5.611500e-002

2

7470

3.735000e-002

3

4678

2.339000e-002

4

2498

1.249000e-002

5

1178

5.890000e-003

6

511

2.555000e-003

7

150

7.500000e-004

8

33

1.650000e-004

9

2

1.000000e-005

10

1

5.000000e-006

Figure 5.1:      Performance of WCDMA in 2-Rays AWGN Channels for 1 user

5.1.2 Performance Analysis of QPSK modulation technique of WCDMA in AWGN and Multipath Fading Channel

The simulation of BER is done in the range of 0 to 20 of EbNo. The BER graphs of various Doppler shifts are simulated on the same graph as it is shown in figure 4.10. The y axis of BER is blown up to depict the behavior in Doppler shift environment.

Table 5.2:       Simulation results for evaluation on BER vs. SNR for 2-ray Multipath Rayleigh Fading channel for 1 user when the number of data is 200,000 at 60 kmph

Signal to noise ratio

(EbNo)

No. of Error

Bit Error Rate (BER)

0

27889

1.394450e-001

2

20441

1.022050e-001

4

14529

7.264500e-002

6

9742

4.871000e-002

8

6494

3.247000e-002

10

4197

2.098500e-002

12

2926

1.463000e-002

14

1888

9.440000e-003

16

1261

6.305000e-003

18

916

4.580000e-003

20

614

3.070000e-003

Table 5.1.3:    Simulation result for evaluation on BER vs. SNR for 2-ray Multipath Rayleigh Fading channel for 1 user when the number of data is 200,000 at 90 kmph

Signal to noise ratio

(EbNo)

No. of Error

Bit Error Rate (BER)

0

27464

1.373200e-001

2

20213

1.010650e-001

4

14046

7.023000e-002

6

9146

4.573000e-002

8

6147

3.073500e-002

10

3983

1.991500e-002

12

2649

1.324500e-002

14

1662

8.310000e-003

16

1059

5.295000e-003

18

681

3.405000e-003

20

415

2.075000e-003

Table 5.4:       Simulation result for evaluation on BER vs. SNR for 2-ray Multipath Rayleigh Fading channel for 1 user when the number of data is 200,000 at   120 kmph

Signal to noise ratio

(EbNo)

No. of Error

Bit Error Rate (BER)

0

27920

1.396000e-001

2

20820

1.041000e-001

4

14570

7.285000e-002

6

9998

4.999000e-002

8

6708

3.354000e-002

10

4436

2.218000e-002

12

2889

1.444500e-002

14

1878

9.390000e-003

16

1240

6.200000e-003

18

794

3.970000e-003

20

543

2.715000e-003

Figure 5.2:      Performance of WCDMA in 2-Rays Multipath Rayleigh Fading Channels for 1 user

5.1.3 Performance Analysis Comparison of QPSK Modulation Technique of WCDMA Between AWGN and Rayleigh Fading Channel

Table 5.5:       Simulation result for evaluation on BER vs. SNR for 2-ray AWGN channel for 1 user when the number of data is 200,000

Signal to noise ratio

(EbNo)

No. of Error

Bit Error Rate (BER)

0

15702

7.851000e-002

1

11223

5.611500e-002

2

7470

3.735000e-002

3

4678

2.339000e-002

4

2498

1.249000e-002

5

1178

5.890000e-003

6

511

2.555000e-003

7

150

7.500000e-004

8

33

1.650000e-004

9

2

1.000000e-005

10

1

5.000000e-006

Table 5.6:       Simulation result for evaluation on BER vs. SNR for 2-ray Multipath

                        Rayleigh channel for 1 user when the number of data is 200,000

Signal to noise ratio

(EbNo)

No. of Error

Bit Error Rate (BER)

0

21507

1.075350e-001

1

18064

9.032000e-002

2

15184

7.592000e-002

3

12274

6.137000e-002

4

10397

5.198500e-002

5

8523

4.261500e-002

6

7006

3.503000e-002

7

5921

2.960500e-002

8

4914

2.457000e-002

9

4043

2.021500e-002

10

3380

1.690000e-002

Figure 5.3:      Performance Comparison of WCDMA in 2-Rays Between AWGN and Multipath Rayleigh Fading Channels for 1 user

Table 5.7:       Simulation result for evaluation on BER vs. SNR for 2-ray AWGN channel for 5 user when the number of data is 10,00000

Signal to noise ratio

(EbNo)

No. of Error

Bit Error Rate (BER)

0

94968

9.496800e-002

2

56341

5.634100e-002

4

29272

2.927200e-002

6

13416

1.341600e-002

8

5518

5.518000e-003

10

1805

1.805000e-003

12

501

5.010000e-004

14

89

8.900000e-005

16

1

1.000000e-006

18

0

0.000000e+000

20

0

0.000000e+000

Table 5.8:       Simulation result for evaluation on BER vs. SNR for 2-ray Multipath

                        Rayleigh channel for 5 user when the number of data is 100,0000

Signal to noise ratio

(EbNo)

No. of Error

Bit Error Rate (BER)

0

120236

1.202360e-001

2

87682

8.768200e-002

4

62477

6.247700e-002

6

43558

4.355800e-002

8

30707

3.070700e-002

10

20829

2.082900e-002

12

13940

1.394000e-002

14

8845

8.845000e-003

16

5241

5.241000e-003

18

2801

2.801000e-003

20

1416

1.416000e-003

Figure 5.4:      Performance Comparison of WCDMA in 2-Rays Between AWGN and Multipath Rayleigh Fading Channels for 5 user

5.1.4 Performance Analysis of 16-QAM modulation technique of WCDMA in AWGN

Figure 5.5:            Performance Comparison of 16-QAM in WCDMA system in AWGN

channel

5.1.5 Performance Analysis of 16QAM modulation technique of WCDMA in AWGN and Multipath Fading Channel

We can not obtain any results in this scenario as the results are inconsistent and uncertain. Therefore, we can not investigate the performance of W-CDMA for this scenario.

5.2 Analysis and Discussion

The result shows that each QPSK and 16-QAM modulation techniques in AWGN channel has good performance when it is compared to that of Multipath Rayleigh channel. Also, the performance of QPSK and 16-QAM degrades when the channel is subjected to Multipath fading with increasing value of Doppler shift (Hz). Moreover, the system performs badly as the number of users is increased. Comparison between QPSK and 16-QAM modulation schemes shows that 16-QAM performs very poorly in both AWGN (LOS channel) and AWGN with Multipath fading channel. The simulation of 16-QAM modulation technique using m files cannot be done because it is suspected that the variation of amplitude with phase causes errors in the constellation of 16-QAM signal.

The reason behind this poor performance of 16-QAM of W-CDMA system in multipath fading channel is basically due to the interference between adjacent carriers phase in the constellation of 16-ary QAM.

It is suggested that error correction coding such as convolution coding or turbo coding is used in this system to ensure better performance of QPSK modulation technique of WCDMA system. Also, it is possible to consider the use of a RAKE receiver or a smart antenna (MIMO) in this system to exploit the delayed signals generated in multipath fading channel. It is discovered, as well, that the performance of multi-user in the m file is limited to a maximum of 7 users. Thus, this system needs to be improved to simulate more number of users so that the performance of multiple accesses in WCDMA can be studied more dynamically.

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Saturday, April 28, 2012

RESULT AND DISCUSSION of WCDMA SYSTEM WITH DIFFERENT CHANNEL CONDITIONS

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Signal to noise ratio (EbNo)	No. of Error	Bit Error Rate (BER)
0	15702	7.851000e-002
1	11223	5.611500e-002
2	7470	3.735000e-002
3	4678	2.339000e-002
4	2498	1.249000e-002
5	1178	5.890000e-003
6	511	2.555000e-003
7	150	7.500000e-004
8	33	1.650000e-004
9	2	1.000000e-005
10	1	5.000000e-006