Delay-Tolerant Space-Time Coding and Decoding for Femto-Assisted Cellular Networks

Recently, Delay-Tolerant Space-Time Codes (DT-STCs) have been designed for cooperative communications. They are optimal in synchronous transmission and preserve their full-diversity order for arbitrary delays in asynchronous case. In this paper, we investigate these DT-STCs in femtocell networks where Femtocell Access Points can assist Macrocell Base Stations to transmit data information to users. The delays can be randomly introduced by the MBSs-FAPs backhaul links. We consider concatenated DT-STCs based on previous designs and we address their optimal and sub-optimal decoding schemes. In order to reduce the complexity, we propose a new sub-optimal algorithm based on successive sub-codewords decoding. Simulation results show that the proposed decoder achieves good performance-complexity tradeoff.