Turbo Coded OFDM Combined with MIMO Antennas Based on Matched Interleaver for Coded-Cooperative Wireless Communication  
[PERSON]  
1 College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China; [EMAIL_ADDRESS] (F.Y. ); [EMAIL_ADDRESS] (S.M. )1 College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China; [EMAIL_ADDRESS] (F.Y. ); mughalshoaib@hotmail. \"decoded and forward (DF)\" and \"amplify and forward (AF)\" were developed for improving the bit error rate (BER) but at the cost of reduced spectral efficiency [3]. After a year or so the same authors in [3] published a paper [4] in which they conceived the idea of user cooperation in space-time domain and developed the distributed space time coding protocol that fully exploits spatial diversity among cooperating users. After that, a slightly different framework has emerged in the literature commonly known as coded cooperation [5]. In this technique, instead of only repeating information bits, each user transmits an extra redundancy for its cooperating partner. Later this technique was also developed for multiple cooperating users [6]. The distributed coded cooperation scheme based in turbo code was originally investigated in [7]. Moreover, there has been a plethora of research on wireless cooperative communication systems using massive relays. The authors in [8] investigated the performance analysis of coded cooperation communication in cluster of relays. The authors in [9] implemented the classical Reed Muller code [10] in coded cooperation scenario over multiple relays. In broadband wireless communication, OFDM is an effective technique that mitigates the effect of inter-symbol interference (ISI) and offers high spectral efficiency. The combination of OFDM with MIMO antennas has been very famous over the last two decades as it effectively exploits spatial and frequency diversities in frequency selective MIMO channels [11]. In order to get more benefit in terms of spatial and temporal diversities the authors in [12] have considered an application of an amplify and forward protocol in OFDM system. In [13] authors have analyzed the performance of MIMO-OFDM system in relay-assisted user-cooperative wireless communication. A coded OFDM based on time division multiple access scheme in cooperative wireless communication was investigated in [14]. This scheme is similar to the previously coded cooperative schemes [5] in which a source node broadcasts all its subcarrier towards both destination and partner user (relay) in first half of the code word in a first time slot. After successfully decoding, the partner user will re-transmit all the subcarriers to the destination in second half of the code word in a second time slot. Recently an author in [15] has investigated the performance of the OFDM system based on decode and forward cooperative communication using multiple relays over time dispersive fading channels. Many researchers have focused their attention on developing better cooperative strategies in order to make a practical wireless standard for future wireless communication systems. Nevertheless, there has not been much work reported in the literature that exploits the basic structure of the channel code to enhance diversity through coded-cooperation. More specifically, in case of turbo code, employing good interleavers design always plays a critical role in enhancing the overall bit error rate (BER) performance of the code in a coded cooperation wireless system [16]. A plethora of research has already been done in designing suitable interleaver in [17]. Furthermore, it has been found in [18] that CMI qualifies to be an optimum choice of interleaver. The area of distributed turbo coded cooperation in a fast Rayleigh fading channels using OFDM associated with Alamouti space time block code (STBC) with code matched interleaver at the relay have been unexplored to date. This paper aims to investigate the above scenario.