Indonesian Journal of Electrical Engineering and Computer Science Vol. 11, No. 3, September 2018, pp. 898~907 ISSN: 2502-4752, DOI: 10.11591/ ijeecs.v11.i3.pp898-907  898 Journal homepage: http://iaescore.com/journals/index.php/ijeecs Performance Improvement of MIMO-OSTBC System with BCH-TURBO Code In Rayleigh Fading Channel Sofi Naima 1 , Debbat Fatima 2 , Bendimerad Fethi. Tarik 3 1,3 Department of telecommunications, LTT laboratory, university of tlemcen, Algeria 2 Department of informatics, Mascara University, Algeria Article Info ABSTRACT Article history: Received Oct 9, 2017 Revised May 15, 2018 Accepted Jun 7, 2018 Recently, OSTBCs has become a widespread technique for signal transmission over wireless channels because of their diversity gain, but there are not designed to achieve an additional coding gain. Hence, OSTBCs must be concatenated with an external code which allows a significant coding gain. FEC (forward error correction) is a technique used for detecting and possibly correcting errors that can occur when messages are transmitted through a digital communication system, also for rendering the information more reliable. Thus, with staffing these coding techniques that are able to reach Shannon limits, in MIMO systems, better performances can be achieved by taking advantages of diversity and coding gains. The objective of this paper is to compare different FEC codes in Rayleigh fading channel and propose an appropriate code for M IM O-OSTBC systems. The simulation results reveal the performance of the proposed model. Keywords: BCH BCH-TC CC MIMO OSTBC RS TC Copyright © 2018 Institute of Advanced Engineering and Science. All rights reserved. Corresponding Author: Sofi Naima, Department of telecommunications, LTT laboratory, university of tlemcen, Algeria. Email: dr_sofi_naima@hotmail.com 1. INTRODUCTION In recent decades, and because of the ever increasing demand for efficient and reliable digital transmission, new methods have emerged to meet this massive communications demand under constraints of limited bandwidth and transmit power. MIMO technology is one of the most important research areas in communications, it uses multiple antennas in transmitter and/or receiver, and it can achieve the high diversity gain through STC and high data rate with spatial multiplexing [1] and also assures high speed transmission with a minimum loss in quality of services. Intense research activity has appeared on MIMO systems and it was inspired by different works of Telatar and Foschini [2]. Space time block codes (STBCs) from orthogonal design are attractive since they achieve the maximum diversity gain and the highest throughput .it is an elegant method for transmission using multiple transmit antennas. And these codes have a simple decoding algorithm which is only based on linear processing [3], [4]. Despite its advantages, this coding system does not generally provide coding gain. Unless concatenated with an outer code. In this context, several studies have been done on the concatenation of FEC and STBC that try to find a good combination with minimum complexity and with high coding gain as with high error correction. In [5] different schemes of concatenated STBC and channel coding as TCM (trellis codes modulation), CC (Convolutional Code), turbo, turbo BCH and Turbo TCM was been analyzed and it showed that TC (turbo