Space Time/Space Frequency Processing of MIMO-OFDM Systems: 4G and Beyond 4G Systems

The growing demand for multimedia applications and the growth of internet related content has increased interest for high speed communications in practical environments. To achieve these goals multiple transmit and receive antennas are employed to form multiple input multiple output (MIMO) channels. MIMO systems help to improve system capacity through spatial multiplexing, reliability through diversity and interference reduction in multiple users by exploiting spatial dimension. To further improve system capacity and mitigation against fading, MIMO systems are combined with orthogonal frequency division multiplexing (OFDM) to form MIMO-OFDM systems. These systems are adopted as a basis of 4G and beyond wireless communication standards.