Implementation and performance analysis of Alamouti algorithm for MIMO 2×2 using Wireless Open-Access Research Platform (WARP)

Abstract

In this paper, an implementation of MIMO 2x2 sys tem using Alamouti algorithm on Wireless Open Access Research Platform (WARP) is presented. The performance of the proposed system is evaluated in terms of Bit-error-rate (BER) for different environments that are indoor and outdoor which of each have Line-of-Sight (LOS) and non-Line-of-sight (NLOS) conditions. Afterwards, in order to validate the capability of the proposed system, SISO and MISO systems are also implemented. By an experimental analysis, MIMO system with NLOS condition in both indoor and outdoor environments show better performance than MISO and SISO. Meanwhile, for the conditions of LOS in both indoor and outdoor environment, the performance of SISO system is better than MIMO and MISO. In the case of NLOS conditions, the performance of proposed system is also examined and compared in the both environments. In indoor environment, at transmit power -21.48 dBm, MIMO, MISO and SISO systems have BER value of each of 1.172 x 10-4 , 1.146xl0-I , and 0.2551, respectively. Finally, in outdoor environment, at transmit power -25 dBm, MIMO system achieves BER of 0 better than MISO and SISO which achieves BER of 3.1 x 10-3 and 0.21, respectively.Keywords-bit error rate; line-oj-sigh; multipath; MIMO I. INTRODU CT IONAn increase in the need for data rate is currently very high, so that is required a technology that could solve this problem. MIMO is one of the technologies used to increase the capacity and the data rates of wireless communication systems. MIMO (Multiple Input Multiple Output) is defined as the usage of multi-antennas in transmitter and receiver of wireless communication system [1]. The ability of MIMO system to increase spectrum efficiency and data rate is achieved by employing space diversity [2]. In the literature, there exist several space time schemes for MIMO, such as Bell Laboratories Layered Space Time (BLAST) algorithm and Alamouti algorithm. BLAST algorithm was proposed for wireless communication system with Rayleigh fading channel, where the transmitter did not has the information of channel condition [3]. By using this algorithm, system capacity increases linearly in constant bandwidth and radiated power. Another scheme was proposed by Alamouti in 1998 which uses space time coding with 2 transmitter antennas and 1 receiver antenna. In order to increase the perfonnance system in tenns of data rate, Alamouti algorithm utilized simple transmit diversity in the transmitter side [4].Many implementations of MIMO system using Alamouti 978-1-4799-6432-1114/$31.00 ©20 14 IEEE 438 algorithm were reported [5]-[9]. In [5], a prototype plat form based on FPGA for MIMO System was proposed by implementing Alamouti scheme which utilized 2 transmitter antennas and 1 receiver antenna. FPGA-based OFDM System using Alamouti Algorithm with transmit diversity was also proposed in [6] for HDTV Transmission. Alamouti algorithm with detector log-likelihood ratio (LLR) at receiver antenna for MIMO System was also implemented on a FPGA [7]. The implementation of ...

SDR Design and Implementation of Differential STBC Transmission

“…Consequently, BPSK transmission is not possible with this set-up. Nevertheless, QPSK has a better spectral efficiency and is used in many SDR test beds [9,15]. It is important to note that the conventional OSTBC scheme [4] only gives full-rate for real constellation such as BPSK.…”

“…The main advantage of 2 × 1 MISO systemsis the full capacity order. Nevertheless, according to authors in [15] and [16], 2 × 2 MIMO has some advantages over 2 × 1 MISO. The diversity gain is double because the number of different paths is double.…”