A new MIMO detector for iterative decoding with multiple antenna systems

Recent research has shown that it is possible to achieve near capacity performance with multiple antennas using iterative techniques with an outer channel code. For the iterative multi-input multi-output (MIMO) system to operate at extremely high data rates, the design and development of practically feasible inner MIMO detector is an important issue. A new soft-input soft-output MIMO detector is presented in this paper. A tree-like algorithm is developed by arranging the maximum a posteriori equations in a specific form, The algorithm exploits the concepts of ordering, symbol cancellation, interference nulling and multiple quantization, which have been very successful in Vertical Bell laboratories layered space time (V-Blast) system. Monte-Carlo simulations are presented analyzing different aspects of the soft detector. The performance is also compared with other well-known iterative methods including the modified sphere decoder used with outer convolutional and turbo codes. Results presented show that the detector not only has very good performance, but also has many practical advantages, compared to other methods, like an ability to easily control performance-complexity tradeoff