Performance Analysis of Spatially Coded OFDM Wireless Systems Using Channel State Information

Abstract

With the dawn of next-generation technologies, the current as well as future wireless communication systems are driven by applications that are mostly multimedia-based. And, it requires a humongous exchange of data in terms of audio/video content, which poses a challenge to enable the high data-rate capable communication networks. The combination of spatial-coding techniques and multicarrier transmission has been found as an appropriate choice for supporting the high data-rate/capacity without compromising the performance of wireless systems. The orthogonal-frequency-division-multiplexing (OFDM) has been recognized as a promising candidate for the multicarrier communication technique. The exclusive feature of OFDM is its capability to divide the allocated bandwidth into a number of orthogonal narrowband subchannels (overlapping) that transforms a frequency-selective channel into a set of frequency-nonselective flat-fading subchannels. In addition, the deployment of multi-antennas for wireless transmission and reception introduces subchannels in the spatial-domain, by which, a set of subchannels are established over the same time and frequency parallely. Therefore, the high data-rate services can be catered to the wireless communication users by utilizing the spatially-coded OFDM systems without the requirement of extra bandwidth, by enhancing signal-to-noise-ratio (SNR) at the receiving end. Due to a crucial need for channel-state-information (CSI) in the spatially-coded OFDM systems, the channel estimation/prediction has emerged as an integral part of such systems, which provides an opportunity to combat the adverse effects of fading, interference and noise/disturbances. It also enhances the information symbol-detection rate at the wireless receiver. Therefore, the spatially-coded OFDM strategies stand as a promising choice also for the future high data-rate communication techniques.