Very-large-scale integration hardware implementation of adaptive space-time coding/spatial multiplexing switching

Multiple input multiple output (MIMO) techniques are widely employed in modern wireless systems. The most prominent approaches to MIMO communication are space-time coding (STC) and spatial multiplexing (SM). Less studied is a hybrid technique called adaptive MIMO switching (AMS), which may be employed by fixing the transmission rate and selecting between space-time block coding and SM transmission modes based on instantaneous channel conditions to achieve the most efficient link. This study presents a hardware implementations of a selector algorithm and a detector employing it. The detector is designed for a 2×2 MIMO system and was implemented on an Altera Cyclone II FPGA. In addition, two transmission protocols with decision feedback from the receiver to the transmitter via a low-rate feedback channel are introduced and the feasibility of switching for high-data-rate transmissions is discussed.