UMTS FDD frequency domain equalization based on slot segmentation

A new chip-level MMSE frequency domain equalizer (FDE) is investigated for a universal mobile telephone system (UMTS) downlink. Multiple access interference (MAI) and inter chip interference (ICI) can be reduced at the chip level before despreading. By exploiting the frame and slot structures of the UMTS downlink, the pilots within one slot (for FDD mode) can be used for the required cyclic reconstruction in an FDE. No cyclic prefix (CP) or zero-padding is required at the transmitter, which would change the signal format of the current UMTS system. Furthermore, one slot signal is split into multiple segments for the sake of combating channel variance within one slot. The performance of the proposed MMSE-FDE is studied through simulation. A multimode receiver that can equalize both UMTS and OFDM systems in one structure is then feasible.