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Figure from:A Comprehensive Study and Performance Comparison of M-ARY Modulation Schemes for an Efficient Wireless Mobile Communication System

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International Journal of Computer Science, Engineering and Applications IJCSEA) Vol.1, No.3, June 2011 Figure 8: Reproduction of transmitted voice signal at receiving end for the value of EbNo=6dB after transmitting through AWGN channel [a) MPSK, b)MQAM, c)MFSK for M=16].

Figure 8 International Journal of Computer Science, Engineering and Applications IJCSEA) Vol.1, No.3, June 2011 Figure 8: Reproduction of transmitted voice signal at receiving end for the value of EbNo=6dB after transmitting through AWGN channel [a) MPSK, b)MQAM, c)MFSK for M=16].

Related Figures (10)

Figure 1 Block diagram of digital communication system based on M-ary (MPSK, MQAM MEFSK) modulation scheme. Figure 1 shows the block diagram of presented communication system model utilizing M-ary (MPSK, MQAM, MFSK) modulation scheme. This is a point-to point communication system model [8]. The figure indicates the step by step operation of each functional block. At the transmitter side, the input binary data stream obtained from the recorded voice signal. The retrieved binary data stream is passed through the other required steps (source of encoder channel coder) as the signal has to transmit. Our main observation is concentrated to the nex block (M-array modulator) of the considered communication system model where we were planned to vary the modulation order of different modulation schemes to analysis thei performances. The performance and characteristics of a system is significantly depended on the choice of digital modulation scheme. There is no basic rule for choosing a scheme. However one scheme is better than other depending of the channel, required levels of performance anc arget hardware trade-offs [9]. Nevertheless, it also must be considered the required data rate atency, link budget as well as available bandwidth. At the receiver side, the received signal is demodulated, and passed through the other subsequent blocks in order to reproduce the transmitted speech signal.
Figure 1 Block diagram of digital communication system based on M-ary (MPSK, MQAM MEFSK) modulation scheme. Figure 1 shows the block diagram of presented communication system model utilizing M-ary (MPSK, MQAM, MFSK) modulation scheme. This is a point-to point communication system model [8]. The figure indicates the step by step operation of each functional block. At the transmitter side, the input binary data stream obtained from the recorded voice signal. The retrieved binary data stream is passed through the other required steps (source of encoder channel coder) as the signal has to transmit. Our main observation is concentrated to the nex block (M-array modulator) of the considered communication system model where we were planned to vary the modulation order of different modulation schemes to analysis thei performances. The performance and characteristics of a system is significantly depended on the choice of digital modulation scheme. There is no basic rule for choosing a scheme. However one scheme is better than other depending of the channel, required levels of performance anc arget hardware trade-offs [9]. Nevertheless, it also must be considered the required data rate atency, link budget as well as available bandwidth. At the receiver side, the received signal is demodulated, and passed through the other subsequent blocks in order to reproduce the transmitted speech signal.
The closed forms of Eq.(1) are equations (3) and (4) for first and second approximation, respectively. These equations can be applied to calculate the error probability in terms of SNR per bit. It is necessary to increase the transmitted power in order to maintain the same performance level for higher M. But we can not say the Eq.(1) is a closed form. Therefore, we have to calculate it numerically, which is not so easy. To do this, we have to take some approximations to calculate the error probability. If we apply union boundary conditions and variants then the Eq.(1) can be written aa 3.2. Error probability of MQAM The bit error probability Pyg4m for M-ary QAM modulation scheme is given by [10, 11]
The closed forms of Eq.(1) are equations (3) and (4) for first and second approximation, respectively. These equations can be applied to calculate the error probability in terms of SNR per bit. It is necessary to increase the transmitted power in order to maintain the same performance level for higher M. But we can not say the Eq.(1) is a closed form. Therefore, we have to calculate it numerically, which is not so easy. To do this, we have to take some approximations to calculate the error probability. If we apply union boundary conditions and variants then the Eq.(1) can be written aa 3.2. Error probability of MQAM The bit error probability Pyg4m for M-ary QAM modulation scheme is given by [10, 11]
Figure 2: Original recorded voice signal Figure 2 illustrates an image of recoded voice signal. The signal has been downloaded from the website. This signal is used as transmitted signal and reproduces it at the receiver end through out the whole work for different values of signal to noise ratio ranging from 0 to 12 dB. Figure 3 shows the comparison of MPSK, MFSK and MQAM as a bit error probability for modulation order M=2. The bit error rate is sharply decreased with respect to signal to noise ratio. From this figure, it is clear that, the performance of MPSK is better than that of others. However, MPSK and MQAM show almost smaller result whereas MFSK shows higher bit error rate. More that one order of magnitude higher BER value can be found in MFSK at the SNR=6 dB than that of other modulation techniques. Reproduction of original voice signal with modulation order M=2 is shown in Figure 4. As we mention earlier that MPSK and MQAM show similar value which is also found in the reproduced signals ( 4.a and 4.b). On the other hand, figure 4.c shows distortion in the reproduced signal of MFSK.
Figure 2: Original recorded voice signal Figure 2 illustrates an image of recoded voice signal. The signal has been downloaded from the website. This signal is used as transmitted signal and reproduces it at the receiver end through out the whole work for different values of signal to noise ratio ranging from 0 to 12 dB. Figure 3 shows the comparison of MPSK, MFSK and MQAM as a bit error probability for modulation order M=2. The bit error rate is sharply decreased with respect to signal to noise ratio. From this figure, it is clear that, the performance of MPSK is better than that of others. However, MPSK and MQAM show almost smaller result whereas MFSK shows higher bit error rate. More that one order of magnitude higher BER value can be found in MFSK at the SNR=6 dB than that of other modulation techniques. Reproduction of original voice signal with modulation order M=2 is shown in Figure 4. As we mention earlier that MPSK and MQAM show similar value which is also found in the reproduced signals ( 4.a and 4.b). On the other hand, figure 4.c shows distortion in the reproduced signal of MFSK.
International Journal of Computer Science, Engineering and Applications (IJCSEA) Vol.1, No.3, June 2011
International Journal of Computer Science, Engineering and Applications (IJCSEA) Vol.1, No.3, June 2011
Figure 3: System performance under different modulation schemes (MPSK, MQAM, and MFSK) for M=2. Figure 5: System performance under different modulation schemes (MPSK, MQAM, and MFSK) for M=4.
Figure 3: System performance under different modulation schemes (MPSK, MQAM, and MFSK) for M=2. Figure 5: System performance under different modulation schemes (MPSK, MQAM, and MFSK) for M=4.
Figure 4: Reproduction of transmitted voice at receiving end for the value of EbDNo=6dB after transmitting through AWGN channel [a) MPSK, b) MQAM, c) MFSK for M=2].
Figure 4: Reproduction of transmitted voice at receiving end for the value of EbDNo=6dB after transmitting through AWGN channel [a) MPSK, b) MQAM, c) MFSK for M=2].
Figure 6: Reproduction of transmitted voice at receiving end for the value of EoDNo=6dB after transmitting through AWGN channel [a) MPSK, b) MQAM, c) MFSK for M=4].
Figure 6: Reproduction of transmitted voice at receiving end for the value of EoDNo=6dB after transmitting through AWGN channel [a) MPSK, b) MQAM, c) MFSK for M=4].
Figure 7: System performance under different modulation schemes (MPSK, MQAM, and MFSK) for M=16.
Figure 7: System performance under different modulation schemes (MPSK, MQAM, and MFSK) for M=16.
Figure 9: The performance of MPSK modulation schemes under different modulation orders.
Figure 9: The performance of MPSK modulation schemes under different modulation orders.