Design and Enhancement of Space-Time Block-Code for MC-CDMA OFDM by Phase Matrix in Flat and Selective Fading Channels
Alhamzah Taher Mohammed
Alhamzah Taher Mohammed, Middle Technical University, Baghdad, Iraq Institute of Technology Baghdad, Iraq, India.
Manuscript received on June 19, 2015. | Revised Manuscript received on June 28, 2015. | Manuscript published on July 05, 2015. | PP: 13-17 | Volume-5 Issue-3, July 2015. | Retrieval Number: C2629075315/2015©BEIESP

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©The Authors. Published By: Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/

Abstract: In this paper, we combine a space-time block code (STBC) with a multi-carrier code division multiple access (MC-CDMA) system. MC-CDMA is probable to be one of the most promising access methods for future wireless communication schemes. In fact, MC-CDMA achievements the benefits of both the orthogonal frequency division multiplex (OFDM) multi-carrier modulation and of the code division multiple access (CDMA) technique. A development of space-time, block-coded (STBC) multicarrier code-division multiple-access (MC-CDMA) system using phase matrix in multipath fading channel is proposed, and the performance of the system is analyzed. The bit error rates BER numerical results show that the better performance of the STBC-MC-CDMA system with phase matrix can be achieved when comparing with system without using phase matrix. As a result, it can be seen from the proposed technique that a high performance improvement was obtained over the conventional MC-CDMA, where the Bit Error Rate (BER) is mainly reduced under different channel characteristics for frequency selective fading and the AWGN channel.
Keywords: STBC, OFDM, MC-CDMA, OFDM, IFFT, DFT, Phase matrix.