Reliability-based hybrid MMSE/subspace-max-log-APP MIMO detector

We present an algorithm which is a flexible and scalable trade-off both in complexity and performance between unbiased MMSE and Max-Log-APP MIMO detection. In a first step, LLRs are generated based on linear detection (Max-Log per stream). A predefined number of LLRs is chosen as 'reliable' based on LLR magnitude. For the remaining 'unreliable' subspace we compute the joint Max-Log-APP solution. The algorithm contains unbiased MMSE detection as well as full Max-Log-APP detection as special cases and is suited for iterative detection-decoding.