A Proposed Model for MC-CDMA Based In-Place Wavelet Transform

Abstract

In this paper, a proposed model for Multicarrier-Code Division Multiple Access (MC-CDMA) lying in In-Place Wavelet Transform (IP-WT) algorithm was introduced and analyzed under the Additive White Gaussian Noise (AWGN) channel, flat fading channel and frequency selective fading channel. The performance of the proposed system was compared with the traditional model of MC-CDMA based Fast Fourier Transform (FFT). The proposed model does not need an additional array at each sweep such as the ordered fast Haar wavelet transform, this property will reduce the processing time and the memory size. The results show that the proposed model has an active performance under different channel characteristics.

Performance Study of OFDM Based on In-Place Wavelet Transform

“…To improve the bandwidth efficiency and ISI, ICI, DWT-OFDM was proposed. Salih M., et al [6] was proposed a new model for Multicarrier-Code Division Multiple Access (MC-CDMA) based on In-place Wavelet Transform (IP-WT), the ordered Haar wavelet transform requires additional arrays at each sweep, and it assumes that the whole sample is known at the start of the algorithm. In contrast, some applications require real-time processing as the signal proceeds, which precludes any knowledge of the whole sample, and some applications involve arrays so large that they do not allow sufficient space for additional arrays at each sweep.…”

Performance Improvement of OFDM by 2-Dimensional Wavelet Transform in Flat Fading Channel

“…To improve the bandwidth efficiency and to reduce the ISI, ICI, DWT-OFDM was proposed. Salih M., et al [6] was proposed a new model for Multicarrier-Code Division Multiple Access (MC-CDMA) based on In-Place Wavelet Transform (IP-WT). The ordered Haar wavelet transform requires additional arrays at each sweep, and it assumes that the whole sample is known at the start of the algorithm, in contrast, some applications require real-time processing as the signal proceeds, which precludes any knowledge of the whole sample, and some applications involve arrays so large that they do not allow sufficient space for additional arrays at each sweep.…”

A Proposed Turbo Coded Wavelet Packet Modulation based MC-CDMA

“…This combination is a useful technique for high speed systems which has the property of variable data rates as well as provides reliable communication system [2].…”

“…In its frequency spectrum, the main lobe does not concentrate energy effectively and side lobe attenuates slowly, the multi path fading and synchronization error will cause severe performance degradation due to inter channel interference ICI, intersymbol interference ISI and multi-access interference MAI. Moreover, the FFT MC_CDMA often restores to cyclic prefix CP to eliminate the ISI and maintain orthogonality between neighboring sub_carriers, which decreases the efficiency of spectrum utilization considerably in some communication scenarios.Due to the higher spectral containment between sub channels, wavelet based OFDM can be better in combating narrowband interference and its inherently more robust with respect to ICI than traditional Fourier filter.Without the CP, the data rate in wavelet systems can surpass those of Fourier implementations, one of its key motivating factors.So, the main and important difference between FFT and DWT based OFDM is that the wavelet based OFDM will not add a cyclic prefix to OFDM system [2]. This property makes the wavelet to combat with FFT for future system.…”

“…So, the main and important difference between FFT and DWT based OFDM is that the wavelet based OFDM will not add a cyclic prefix to OFDM system [2]. This property makes the wavelet to combat with FFT for future system.…”