A multi-layered OFDM system with parallel transmission for multicell cooperative cellular networks

Recent development in multicell cooperation poses significant technical challenges to the design of robust and flexible transmission techniques. A new multi-layered orthogonal frequency-division multiplexing (ML-OFDM) system is proposed in this article to provide a dynamic platform for multicell cooperation with efficient base station coordination capability. The proposed enhanced layers (ELs), which are overlaid with the cellular communication data (the base layer) in both frequency and time domains, can be used for several specific purposes indispensable to multicell cooperation. It provides an efficient way of sharing the necessary information, e.g., channel state information, user data and other transmission parameters, between the collaborative BSs without the requirement of additional signaling or control channels. Overall network efficiency is substantially enhanced due to the reduction of radio resource overhead. Furthermore, cross BS synchronization and multimedia broadcast multicast service for next generation cellular networks can be simultaneously achieved by the proposed parallel orthogonal ELs. The transceiver design for the ML-OFDM system, particularly the modulation/demodulation of the ELs and EL-induced interference cancelation is presented. Overall system performance is further optimized by proposing a power distribution scheme with a set of practical constraints. The performance of the ML-OFDM system is analyzed and verified through numerical simulations.