Cross Layer Optimized Iterative ARQ Receivers for OFDM with Carrier Frequency Offset

An optimized Automatic Repeat Request (ARQ) iterative receiver for Orthogonal Frequency Division Multiplexing (OFDM) transmission, suitable for application in double selective multipath channels with Carrier Frequency offset (CFO) is presented. The receiver is an optimized Maximum Aposteriori (MAP) Turbo processor that exploits information from all available transmissions. The system uses an embedded pilot structure for initial channel estimation. We show that this configuration achieves performance very close to a system without CFO. Therefore, the proposed scheme represents a very efficient adaptive platform for OFDM ARQ with high values of CFO wherein the traditional adaptive approach based on code combining presents an error floor on the packet error probability.