On protection of compressed image in fading channel using data hiding
Computers and Electrical Engineering
Collusion resilient spread spectrum watermarking in M-band wavelets using GA-fuzzy hybridization
Journal of Systems and Software
Wireless Personal Communications: An International Journal
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This paper proposes a high capacity carrier interferometry/multicarrier code division multiple access (CI/MCCDMA)system through the simultaneous support of highand low data rate transmission. High data rate users transmitdata through all sub-carriers while alternate odd andeven subcarriers are shared by the low data rate users.The usage of alternate sub-carriers suggests to split CIcodes in odd and even parts leading to an increase incapacity. The cross-correlations among the code patternsare reduced through the phase shift of even (odd) CI codeusing odd (even) sub-carriers by an amount of π/2 andodd (even) CI code using odd (even) sub-carriers by -π/2,all measured with respect to orthogonal codes assigned tosupport high data rate transmission. Performance in termof BER (bit error rate) is then analyzed by carrying outsimulation on frequency selective Rayleigh fading channel.The MAI (multiple access interference) effect is subtractedat the subcarrier projection domain leading to the reductionin high computation cost inherent in parallel interferencecancelation. Performance improvement for different combinationsof low and high data rate users are shown comparedto the conventional CI/MC-CDMA system as well as blockPIC scheme.