Distributed fast decodable space-frequency coding for CoMP OFDM cellular networks

This paper presents a distributed fast decodable space-frequency coding (FD-SFC) scheme suitable for Coordinated Multi-Point (CoMP) downlink transmission in an OFDM cellular wireless network to mitigate ICI while benefiting from spatial diversity by grouping cell-edge users (UE) and sharing sub-carriers among neighbor cells. A distributed decoder is proposed to reduce the UE decoding complexity to 50% of that of the optimal decoder for the same non-distributed FD-SFC. Achievable transmission rate (in b/s/Hz) versus UE relative distance to its base-station (eNodeB) of the proposed scheme is studied in comparison with the Alamouti CoMP and non-CoMP schemes, and its performance upper and lower bounds are derived. It is shown that the proposed scheme outperforms both Alamouti-CoMP and non-CoMP schemes in serving cell-edge UE´s. The derived performance bounds are then used to establish the UE relative distance threshold for switching between the proposed CoMP and non-CoMP modes to enhance the overall performance.