Implementation of a Soft Output Sphere Decoder by Rapid Prototyping Methodology

During the last decade there has been tremendous growth in wireless communication, with focus on broadband wireless LAN and mobile phones. To meet the demand for faster wireless access there is a need to change from the traditional Single-Input-Single Output (SISO) antenna systems. There has been significant progress in recent times in developing systems that use multiple antennas at the transmitter and receiver to achieve better performance. Multiple-input-multiple-output (MIMO) uses multiple antennas in both transmitter and receiver ends to achieve high spectral efficiency. However the implementation of MIMO systems comes at the cost of increased complexity in the receiver design. The detection of vector of symbols drawn from a finite alphabet when transmitted over a MIMO system poses a challenging implementation task. The aim of this thesis is to use sphere detection algorithm as an efficient means to detect the spatially multiplexed symbols. This thesis discusses the evaluation of the performance and implementation aspects of a Soft output sphere decoder as an efficient detection means for MIMO systems. The implementation is done in MATLAB and C and discusses the prospects of rapid prototyping methodology as an efficient approach towards further implementation.