Decision feedback equalization in SC-FDMA

Abstract

SC-FDMA (Single-Carrier Frequency Division Multiple Access) is employed in the 3GPP LTE (Long-Term Evolution) standard as the uplink transmission scheme. The SC-FDMA signal has a low PAPR. This makes it well-suited to power efficient transmission at the mobile terminal. Although it is a common assumption to use frequency-domain linear equalization in SC-FDMA, a decision feedback equalizer (DFE) composed of a frequency-domain feedforward filter and a time-domain feedback filter can provide enhanced performance. Even when error propagation is taken into account, results show that a DFE still offers a significant performance gain over the conventional LE for uncoded SC-FDMA. This paper demonstrates that SC-FDMA with DFE is capable of increasing the throughput in a power limited channel by up to 41% compared to LE. Alternatively, for a given peak transmit power, the use of a DFE can achieve a 14% coverage extension in NLOS and 19% in LOS.