Recently, we proposed a pseudo block coded single-carrier (PBC-SC) transmission using minimum mean square error (MMSE) based frequency-domain equalization and decoding (FDED) and show that MMSE based FDED achieves BER performance superior to 2-step decoding (which performs frequency-domain equalization and hard decision decoding separately). However, there still exists a large BER performance gap between MMSE based FDED and MF bound due to the presence of residual inter-symbol interference (ISI) after MMSE based FDED. In this paper, in order to narrow the performance gap, we propose frequency-domain block signal detection (FDBD) aided FDEDs for PBC-SC transmission: frequency-domain iterative interference cancellation (FDIC), maximum likelihood block sig-nal detection employing QR decomposition and M algorithm (QRM-MLBD) and belief propagation (BP). We compare, by computer simulation, the BER performances and the computa-tional complexities of three FDBD aided FDED schemes. It is shown that QRM-MLBD and BP can achieve almost the same BER performance as MF bound with much lower computational complexity than MMSE based FDED.