Other-cell interference reducing resource allocation in OFDM-based asynchronous cellular systems
EURASIP Journal on Wireless Communications and Networking - Multicarrier Systems
Robust MC-CDMA-based fingerprinting against time-varying collusion attacks
IEEE Transactions on Information Forensics and Security
Conjugate symmetric sequency-ordered complex Hadamard transform
IEEE Transactions on Signal Processing
WCNC'09 Proceedings of the 2009 IEEE conference on Wireless Communications & Networking Conference
Interference-free code design for MC-CDMA uplink transmissions
IEEE Transactions on Wireless Communications
Spreading code selection methods for MC-CDMA under carrier frequency offset
APCC'09 Proceedings of the 15th Asia-Pacific conference on Communications
Performance of blind successive interference canceller for multi-carrier CDMA systems
WSEAS TRANSACTIONS on COMMUNICATIONS
Collusion-resistant fingerprinting systems: review and recent results
Transactions on data hiding and multimedia security V
Allocation algorithm for optimizing MC-CDMA over correlated channel
WSEAS TRANSACTIONS on COMMUNICATIONS
Comparison of scalable ACC and MC-CDMA for practical video fingerprinting scheme
ICIC'11 Proceedings of the 7th international conference on Advanced Intelligent Computing Theories and Applications: with aspects of artificial intelligence
Sequency-ordered generalized Walsh-Fourier transform
Signal Processing
Hi-index | 35.69 |
It is known that multicarrier code-division multiple-access (MC-CDMA) systems suffer from multiaccess interference (MAI) when the channel is frequency-selective fading. In this paper, we propose a Hadamard-Walsh code-based MC-CDMA system that achieves zero MAI over a frequency-selective fading channel. In particular, we will use appropriately chosen subsets of Hadamard-Walsh code as codewords. For a multipath channel of length L, we partition a Hadamard-Walsh code of size N into G subsets, where G is a power of two with GgesL. We will show that the N/G codewords in any of the G subsets yields an MAI-free system. That is, the number of MAI-free users for each codeword subset is N/G. Furthermore, the system has the additional advantage that it is robust to carrier frequency offset (CFO) in a multipath environment. It is also shown that the MAI-free property allows us to estimate the channel of each user separately and the system can perform channel estimation much more easily. Owing to the MAI-free property, every user can enjoy a channel diversity gain of order L to improve the bit error performance. Finally, we discuss a code priority scheme for a heavily loaded system. Simulation results are given to demonstrate the advantages of the proposed code and code priority schemes