MIMO Wireless Systems: V-BLAST Architecture

Abstract

In this work have a problem of effects of fading. In problem formulation, it is assumed that the capacity gain and link reliability of MIMO (Multi Input Multi Output) systems was maximized that channels between pairs of transmit and receive antennas are independent of each other. The fading channel in wireless communications degrades the system Bit Error Rate (BER) performance significantly. MIMO channel, which employs multiple transmitters and/or multiple receivers, compensate the BER performance difference between fading channel and Additive White Gaussian Noise (AWGN) channel, because multiple replica of the information mitigates the randomness of fading channel. In this, the space diversity is studied and simulated. Space diversity includes two kinds of diversity: transmitter diversity and receiver diversity. Transmitter diversity means multiple transmitters are employed, which leads to Multiple Input Single Output (MISO) channel. Receiver diversity means multiple receivers are employed, which leads to Single Input Multiple Output (SIMO) channel. Employment of both multiple transmitters and receivers leads to Multiple Input Multiple Output (MIMO) channel. MIMO in conjunction with Space-Time Coding, which provides correlation on both temporal and spatial domain, is necessary for multiple transmitter system. We also describe a Space-Time architecture known as vertical BLAST (Bell Laboratories Layered Space-Time) or V-BLAST. The BER performance of these systems for different diversity are simulated and compared.