Performance of SC-FDMA with Transmit Power Allocation and Frequency-Domain Equalization

Single-Carrier Frequency Division Multiple Access (SC-FDMA) has been selected as the uplink transmission scheme in the 3GPP Long Term Evolution standard. SC-FDMA is a form of Single-Carrier Frequency Domain Equalization (SC-FDE) with flexibility in its resource allocation. In this paper we investigate the performance of SC-FDMA with Frequency-Domain Linear Equalization (FD-LE) with optimized transmit power allocation. We derive the optimum power allocation for both Zero-Forcing (ZF) and Minimum Mean-Square Error (MMSE) FD-LE receivers in order to maximize the achievable data rate subject to total transmit power constraint. Results show that optimum transmit power allocation given knowledge of the FD-LE receiver results in a better achievable transmission rate compared to the information theoretic optimum transmit power allocation, which assume an ideal receiver. Results show that the proposed power allocation scheme offers significant increases in the operating range and cell throughput of SC-FDMA system.