Order-recursive precoding for cooperative multi-point transmission

This paper describes an order-recursive algorithm to calculate the Wiener transmit filter for coherent coordinated multi-point transmissions between several decentralized base stations to several decentralized mobile terminals in cellular radio networks. State of the art implementations do not offer the flexibility to handle multiple transmission setups as required for multi-user precoding in conjunction with the proposed reduced complexity. A discussion of all signal processing steps shows how algebraic observations are mapped to physical parameters and how they reflect the spatial eigenmodes. These observations can be integrated into a spatial scheduling process to extend the precoding coefficients recursively with additional spatial streams. Finally, experimental resultqs with a hardware platform for cellular field trials are presented that compare the proposed multiuser interference cancelation technique with a non-cooperative transmission.