Chained Turbo Equalization for Block Transmission without Guard Interval

This paper proposes chained turbo equalization (CHATUE) algorithm, a simple detection scheme for block transmission without guard interval (GI), where turbo equalizers for the several consecutive frames exchange information about the interference components. Although the block transmission without GI can significantly increase bandwidth efficiency, the received signal suffers from inter-block interference (IBI) and intersymbol interference (ISI), which can´t be effectively compensated by block-by-block equalization.With the CHATUE algorithm, the IBI components are cancelled by utilizing a posteriori feedback from the decoders of the neighboring equalizers (future and past). To best utilize the latest results of the sub-optimal reduced complexity equalization, frequency domain soft cancellation and minimum mean squared error filtering (FD/SC-MMSE), we exploit J matrix to convert the Toeplitz channel matrix structure to a circulant matrix. Results of the computer simulation for single carrier block transmission (SCBT) show that the proposed scheme can achieve good performance.