Adaptive Modulation of Ofdm and Mc-cdma System

Proposal of Adaptive Downlink Modulation Using OFDM and MC-CDMA for Future Mobile Communications System

To meet the strong demand for broadband multimedia services by both nomadic and mobile users, it is important to increase the bit rate of future mobile communications systems. To enhance system capacity, novel technologies or new concepts for improving bandwidth efficiency are indispensable. In this paper, an adaptive downlink modulation using OFDM and MC-CDMA is presented for maximizing the sy...

Comparison between MC-CDMA and CDMA- OFDM/OQAM systems in presence of MIMO channel

In this paper, we present a comparison between MCCDMA and CDMA-OFDM/OQAM systems in the case of MIMO channel. The advanced Multi Carrier CDMA OFDM/OQAM modulation is a combination of CDMA and OFDM/OQAM. This combination takes advantages from multicarrier modulation and spread spectrum. Indeed, the use of OFDM has proved its ability to fight against frequency selective channels but the insertion...

Quadrature Amplitude Modulation: From Basics to Adaptive Trellis-Coded, Turbo-Equalised and Space-Time Coded OFDM, CDMA and MC-CDMA Systems

CDMA Transmission with Complex OFDM/OQAM

We propose an alternative to the well-known multicarrier code-division multiple access (MC-CDMA) technique for downlink transmission by replacing the conventional cyclic-prefix orthogonal frequency division multiplexing (OFDM) modulation by an advanced filterbank-based multicarrier system (OFDM/OQAM). Indeed, on one hand, MC-CDMA has already proved its ability to fight against frequency-selecti...

Adaptive Procedure Combining Adaptive User Grouping and Bit- Loading in a Go-mc-cdma

Multi Carrier CDMA (MC-CDMA) has shown better results than conventional OFDM systems due to the frequency diversity we achieve with frequency spreading. This spreading is more effective whichever better subcarrier states are found. So the optimal approach should load the subcarriers adaptively according to the subcarriers state. In this paper we investigate the use of adaptive grouped multicarr...

System performance comparison of Fast-OFDM system and overlapping Multi-carrier DS-CDMA scheme

In this paper, an overlapped Orthogonal Frequency Division Multiplexing (OFDM) named as Fast-OFDM system and an overlapping multi-carrier direct-sequence code division multiple access (MC-DS-CDMA) scheme are introduced. The effect of the overlapping between sub-carriers, of Fast-OFDM and MC-CDMA with binary phase shift keying (BPSK), on the performance in an additive white Gaussian noise (AWGN)...