Unified Joint Symbol and Channel Estimation with Interference Subtraction for One-Way and Two-Way MIMO Relaying Systems

Among the various technologies considered as keys to the implementation of 5G wireless networks, one that stands out is the use of relaying stations capable of increasing coverage area whilst providing cooperative diversity. This work addresses the issue of joint estimation of symbols and channels in a MIMO Amplify-and-Forward (AF) system, whether the relay works on a One-Way Relay (OWR) or Two-Way Relay (TWR) basis. In order to deal with this task, a higher-order multilinear approach is used to model the space-time coding and decoding processes carried out in the communicating nodes. Particularly to mitigate the problem of interference between users, a routine named Interference Subtraction (IS) is used in conjunction with the proposed semi-blind receiver, called DKRF-IS. In this work, uniqueness and identifiability conditions required for the use of the receiver are developed. Performance evaluation using Monte Carlo simulations corroborate the validity of the presented equations and the effectiveness of the proposed receiver.