A synchronous coherent OFDM air interface concept for high data rate cellular systems

This paper continues the investigation of a new air interface concept for future OFDM-based cellular systems called synchronous coherent orthogonal frequency division multiplexing (SC-OFDM). SC-OFDM is based on combination of synchronized cells, orthogonal pilot codes, and a cyclic extension which is large enough to absorb both delay spread and intercell propagation delay. The primary advantages of SC-OFDM are that it mitigates the effect of co-channel interference on desired signal channel estimates and facilitates the direct measurement of the channel response of individual co-channel interfering signals. These measurements provide channel state information and enable the use of interference-mitigating detection techniques such as MMSE diversity combining or joint-detection. The performance of an SC-OFDM downlink air interface is evaluated with computer simulations.