Rasadurai K
@kec.ac.in
Professor, Electronics and Communication Engineering
Kuppam Engineering College
RESEARCH INTERESTS
Electronic Engineering and Telecommunications Engineering, Software Defined Radio, Cognitive Radio, Wireless Broadband Networks
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
K. Rasadurai and N. Kumaratharan
IEEE
Multi carrier code division multiple access (MC-CDMA) is an efficient multi carrier modulation (MCM) technique that mitigates problems like spectral limitation and distortion due to multipath channels. Nevertheless, in a high speed mobile communication channels the orthogonality among subcarriers are destroyed due to multipath fading. The loss of orthogonality can cause inter carrier interference (ICI) and multiple access interference (MAI). The effect of MAI reduces the system performance in term of bit error rate (BER). The Turbo block code (TBC) technique based low density parity check (LDPC) code is proposed to overcome the MAI. It provides better concatenated decoding scheme with lower complexity and higher efficiency for improving the performance of MC-CDMA system in terms of BER and the same is proved through simulation.
Rasadurai Kumaravel and Kumaratharan Narayanaswamy
Public Library of Science (PLoS)
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.
K. Rasadurai, Parvathy S Kumar, and N. Kumaratharan
IEEE
A turbo block code (TBC) technique for improving the performance of a multi-carrier code division multiple access (MC-CDMA) system in terms of bit error rate (BER) is proposed in this paper. The objective of this work is to develop a coding scheme that generates low BER code-words. By implementing a time domain TBC, designed using powerful low density parity check (LDPC) code, the BER performance of MC-CDMA system is improved and the same is proved through simulation. Two types of LDPC codes, viz. random LDPC codes and quasi cyclic (QC) LDPC codes are analyzed. These codes also have error correction capability along with high performance efficiency in terms of BER. In addition a decoding algorithm with moderate decoding complexity and with feasible soft output generation is also proposed for each LDPC code.
K. Rasadurai and N. Kumaratharan
IEEE
In this paper turbo multi-user detection (MUD) technique is proposed for multi carrier code division multiple access (MC-CDMA) system to overcome the affects of multiple access interference (MAI) caused by the inter-cell and intra-cell interference and near far effect. The proposed technique estimates the interference from the unknown users and the interference estimate is subtracted from the received signal. Simulation results show that the turbo multi user detector significantly outperforms the conventional multi user detector for moderate and high signal-to-noise ratios.