Near-optimal soft-output fixed-complexity mimo detection via subspace marginalization and interference suppression

The fundamental problem of our interest here is soft MIMO detection. We propose a method that yields excellent performance, at low and at fixed (deterministic) complexity. Our method provides a well-defined tradeoff between computational complexity and performance. Apart from an initial step consisting of selecting columns, the algorithm involves no searching nor algorithmic branching; hence the algorithm has a completely predictable run-time, and it is readily and massively parallelizable.