On performance analysis of OSTBC-MIMO systems for audio [mp3] transmission in Rayleigh fading environments

Abstract

Many wireless networks are rapidly become part of our daily life. However, range and data rate in wireless devices are limited. One method is to use Multiple-Input Multiple-Output (MIMO) communication system to overcome these limitations. The multiple antennas allow MIMO systems to perform diversity coding (space-time coding), and spatial multiplexing. Beamforming consists of transmitting the same signal with different gain and phase (called weights) over all transmits antennas such that the receiver signal is maximized. Diversity consists of transmitting a single space-time coded stream through all antennas. Spatial multiplexing increases network capacity by splitting a high rate signal into multiple lower rate streams and transmitting them through the different antennas. The results of using these MIMO techniques is higher data rate or longer transmit range without requiring additional bandwidth or transmit power. This paper presents a detailed study of diversity coding for MIMO systems. Different space-time block coding (STBC) schemes including Alamouti's STBC for 2 transmit antennas as well as orthogonal STBC for 3 and 4 transmit antennas are explored. Finally, these OSTBC techniques are implemented in MATLAB and Simulink. Performance analysis is carried out and system results are observed by transmitting mp3 audio clip using QPSK, 16-QAM, and 64-QAM modulation schemes in Rayleigh fading distributions.