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Performance enhancement of MC-CDMA system through novel sensitive bit algorithm aided turbo multi user detection.

Kumaravel R, Narayanaswamy K - PLoS ONE (2015)

Bottom Line: The OFDM parts reduce multipath fading and inter symbol interference (ISI) and the CDMA part increases spectrum utilization.The multiuser detection (MUD) and turbo coding are the two dominant techniques for enhancing the performance of the MC-CDMA systems in terms of BER as a solution of overcome to MAI effects.Simulation results show that the proposed method provides better BER performance with low complexity decoding, by mitigating the detrimental effects of MAI.

View Article: PubMed Central - PubMed

Affiliation: Department of Information Technology, Sri Venkateswara College of Engineering, Pennalur-602117, Sriperumbudur, India.

ABSTRACT
Multi carrier code division multiple access (MC-CDMA) system is a promising multi carrier modulation (MCM) technique for high data rate wireless communication over frequency selective fading channels. MC-CDMA system is a combination of code division multiple access (CDMA) and orthogonal frequency division multiplexing (OFDM). The OFDM parts reduce multipath fading and inter symbol interference (ISI) and the CDMA part increases spectrum utilization. Advantages of this technique are its robustness in case of multipath propagation and improve security with the minimize ISI. Nevertheless, due to the loss of orthogonality at the receiver in a mobile environment, the multiple access interference (MAI) appears. The MAI is one of the factors that degrade the bit error rate (BER) performance of MC-CDMA system. The multiuser detection (MUD) and turbo coding are the two dominant techniques for enhancing the performance of the MC-CDMA systems in terms of BER as a solution of overcome to MAI effects. In this paper a low complexity iterative soft sensitive bits algorithm (SBA) aided logarithmic-Maximum a-Posteriori algorithm (Log MAP) based turbo MUD is proposed. Simulation results show that the proposed method provides better BER performance with low complexity decoding, by mitigating the detrimental effects of MAI.

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Performance of the MC-CDMA system using Log MAP over Rayleigh Channel.
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pone.0115710.g006: Performance of the MC-CDMA system using Log MAP over Rayleigh Channel.

Mentions: Fig. 6 show that the BER performance of the MC-CDMA system using Log MAP algorithm based turbo MUD for various iterations over Rayleigh channel. It is noticed that as the number of iterations increases with 2,4,6,8 and 10 iteration the BER performance improved progressively. In the Fig. 5 and Fig. 6 shows that the performance of system using Log MAP over AWGN channel and Rayleigh channel respectively and it is provided the much better BER for the low values of SNR effectively from 1 dB to 6 dB. It is witnessed that the Log MAP based turbo MUD over AWGN channel outperforms Log MAP based turbo MUD over Rayleigh channel. Hence the BER performance of the system is slightly degraded in Rayleigh channel.


Performance enhancement of MC-CDMA system through novel sensitive bit algorithm aided turbo multi user detection.

Kumaravel R, Narayanaswamy K - PLoS ONE (2015)

Performance of the MC-CDMA system using Log MAP over Rayleigh Channel.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4340792&req=5

pone.0115710.g006: Performance of the MC-CDMA system using Log MAP over Rayleigh Channel.
Mentions: Fig. 6 show that the BER performance of the MC-CDMA system using Log MAP algorithm based turbo MUD for various iterations over Rayleigh channel. It is noticed that as the number of iterations increases with 2,4,6,8 and 10 iteration the BER performance improved progressively. In the Fig. 5 and Fig. 6 shows that the performance of system using Log MAP over AWGN channel and Rayleigh channel respectively and it is provided the much better BER for the low values of SNR effectively from 1 dB to 6 dB. It is witnessed that the Log MAP based turbo MUD over AWGN channel outperforms Log MAP based turbo MUD over Rayleigh channel. Hence the BER performance of the system is slightly degraded in Rayleigh channel.

Bottom Line: The OFDM parts reduce multipath fading and inter symbol interference (ISI) and the CDMA part increases spectrum utilization.The multiuser detection (MUD) and turbo coding are the two dominant techniques for enhancing the performance of the MC-CDMA systems in terms of BER as a solution of overcome to MAI effects.Simulation results show that the proposed method provides better BER performance with low complexity decoding, by mitigating the detrimental effects of MAI.

View Article: PubMed Central - PubMed

Affiliation: Department of Information Technology, Sri Venkateswara College of Engineering, Pennalur-602117, Sriperumbudur, India.

ABSTRACT
Multi carrier code division multiple access (MC-CDMA) system is a promising multi carrier modulation (MCM) technique for high data rate wireless communication over frequency selective fading channels. MC-CDMA system is a combination of code division multiple access (CDMA) and orthogonal frequency division multiplexing (OFDM). The OFDM parts reduce multipath fading and inter symbol interference (ISI) and the CDMA part increases spectrum utilization. Advantages of this technique are its robustness in case of multipath propagation and improve security with the minimize ISI. Nevertheless, due to the loss of orthogonality at the receiver in a mobile environment, the multiple access interference (MAI) appears. The MAI is one of the factors that degrade the bit error rate (BER) performance of MC-CDMA system. The multiuser detection (MUD) and turbo coding are the two dominant techniques for enhancing the performance of the MC-CDMA systems in terms of BER as a solution of overcome to MAI effects. In this paper a low complexity iterative soft sensitive bits algorithm (SBA) aided logarithmic-Maximum a-Posteriori algorithm (Log MAP) based turbo MUD is proposed. Simulation results show that the proposed method provides better BER performance with low complexity decoding, by mitigating the detrimental effects of MAI.

Show MeSH