Remote Sensing Science May 2013, Volume 1, Issue 1, PP.9-14
The LabVIEW Simulation of Space-Time Coding Technique in the MIMO-OFDM System Jiancai Liu#, Shutin Chen, Jiakai Xu College of Electronics Science and Engineering, Nanjing University, Nanjing 210093, P. R. China #
Email: njuliu@163.com
Abstract The space-time coding technology in MIMO system and MIMO-OFDM system is analyzed in this paper. The system performance of the Layered Space-Time Codes (LSTCs), the Space-Time Trellis Codes (STTCs) and the Space-Time Block Codes (STBCs) are studied and compared by means of the LabVIEW simulation, which has also compared the bit error rate (BER) in different signalto-noise ratio (SNR). Several communication systems such as V-BLAST, Trellis and Alamouti coding in different states and different numbers of antennas are simulated by this software. It is proved that the system performance in MIMO system can be effectively improved by means of the space-time coding in BER-SNR graph. We have drawn the conclusion that STTC is the best coding scheme in the three of them. Keywords: MIMO-OFDM; Space-Time Coding (STC); LSTC; STTC; STBC; LabVIEW Simulation
1 INTRODUCTION Orthogonal frequency division multiplexing (OFDM) has attracted a great deal of attention due to its resilience to radio frequency interference, high spectral efficiency, lower multipath distortion and simplified equalization. It has become the basis for the digital audio broadcasting (DAB) and digital video broadcasting (DVB) standards and has been adopted in current WLAN IEEE 802.11a and 802.11g (WiFi) standards [1]. OFDM may be combined with antenna arrays at the transmitter and receiver to increase bandwidth efficiency and/or robustness using multipath signal propagation, resulting in a multiple-input multiple-output (MIMO) configuration. MIMO techniques are now used in the new IEEE 802.11n standard, and will certainly also occur in the forthcoming 802.16e and 3GPP LTE standards. The combination of MIMO and OFDM can achieve a strong reliability through the diversity, and improve the system transmission, which has been regarded as the key technique in the future mobile communication systems [2].
FIGURE 1. MIMO COMMUNICATION USES MULTIPLE ANTENNAS AT BOTH THE TRANSMITTER AND RECEIVER TO EXPLOIT THE SPATIAL DOMAIN FOR SPATIAL MULTIPLEXING AND/OR SPATIAL DIVERSITY.
The theory of space-time coding is studied in this paper and the comprehensive analysis of the LSTC, the STTC and the STBC is made.
2 THE SIMULATION OF THE CHARACTERISTICS OF THE V-BLAST SYSTEM The vertical layered space-time coding scheme in LSTC is simulated by means of the LabVIEW and the V-BLAST -9http://www.ivypub.org/rss