A Pilot decontamination approach using constrained optimization and subspace method for uplink multiuser MIMO system

A pilot decontamination algorithm for uplink multiuser MIMO system based on matrix subspace decomposition and constrained optimization has been suggested. Transmitted pilot and data symbols of each user can be acquired by the scheme when pilot is contaminated by other users. Eigenvalue decomposition is performed on received data matrix and then possible pilot and data symbols are projected on selected subspace. A quadratic form with constrained optimization also been used with received data matrix to compare results.