A sparse recovery method for initial uplink synchronization in OFDMA systems

Initial uplink synchronization is an integral part of wireless communication systems. It enables the base station (BS) to detect new subscriber stations (SS) willing to commence communication. It also enables the BS to estimate the uplink channel parameters of these SSs. Accurate estimation of channel parameters is crucial, as they ensure the uplink signals from all the SSs arrive at the BS synchronously at similar power levels. However, this detection and estimation problem turns out to be very challenging when multiple users initiate the synchronization procedure at the same time. We address this issue by exploiting the underlying sparsity of the estimation problem. We propose a fast sparse signal recovery approach that shows a clear improvement in detection and estimation performance compared to other state-of-the-art methods. The proposed method can be integrated into any OFDM based standard.