Reduction of Phase Noise Influence in MISO SFBC SC-FDMA System

It is very important to achieve high performance in the SC-FDMA (single carrier frequency division multiple access) system that is used for LTE (long term evolution) and LTE-advanced system. To simultaneously resolve ICI(inter-subcarrier interference) and PAPR(peak to average power ratio) problem, focused on the two transmit(Tx) / one receive(Rx) antenna configuration, phase noise influence on the 2 1 SFBC(space frequency block coding) SC-FDMA system is first analyzed, then compared with MISO(multiple input single output) SC-FDMA using several selected ICI self-cancellation methods. SC-FDMA induces more interference problem than OFDM because of the DFT spreading phase offset mismatch caused by random phase noise. By using ICI self-cancellation methods, the system performance significantly improves only by simple data encoding. Simulation results show that in the SFBC SC-FDMA system, the ICI and SCI interference cannot be neglected because 2  1 SFBC SC-FDMA even make phase noise influence seriously due to the simultaneous generation of more SCI and ICI than 2 1 SC-FDMA only, so, interference compensation is necessary. It is found that 2 1 SC-FDMA with data-conjugate ICI selfcancellation method and 2 1 SC-FDMA with symmetric ICI self-cancellation method can achieve considerable performance improvement than 2 1 SFBC SC-FDMA system, besides, data-conjugate method is superior to the symmetric data-conjugate method.