Multi-code DS-CDMA systems assign more than one spreading sequence to each of the users. In these systems multiple access interference (MAI) is made of a synchronous and an asynchronous component. We propose an orthonormalization approach aiming at coupling the advantages of orthogonal code design in countering synchronous MAI with that of chaos-based codes in countering asynchronous MAI. Improvements with respect of classical orthogonal-i.i.d. sequences in terms of signal-tointerference ratio are demonstrated by simulations. The effect of quantization in sequence storing and processing is also taken into account.
Chaos-Based Multi-Carrier CDMA: Orthogonal Subspace Approach
SETTI, Gianluca;MAZZINI, Gianluca;
2005
Abstract
Multi-code DS-CDMA systems assign more than one spreading sequence to each of the users. In these systems multiple access interference (MAI) is made of a synchronous and an asynchronous component. We propose an orthonormalization approach aiming at coupling the advantages of orthogonal code design in countering synchronous MAI with that of chaos-based codes in countering asynchronous MAI. Improvements with respect of classical orthogonal-i.i.d. sequences in terms of signal-tointerference ratio are demonstrated by simulations. The effect of quantization in sequence storing and processing is also taken into account.File in questo prodotto:
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