Different known guard intervals for single-/multi-carrier transceiver

In general, cyclic prefix (CP), zero padding (ZP) or fixed symbol padding (FP) can be seen as the guard interval (GI) for data transmitting. By inserting enough long GI, we can remove inter-block interference (IBI) completely, and the signal distortion due to multi-path environment can be simply compensated by frequency domain equalization (FDE). But on the other hand, the system bandwidth efficiency will be decreased due to the redundancy of GI and additional channel estimation pilots. This paper proposes a new scheme to estimate channel state with the help of our special type GI and presents the FDE scheme based on the proposed GI system