Performance Evaluation of Closed-Loop based Antenna Switching Transmit Diversity Associated with Frequency Domain Channel-Dependent Scheduling in E-UTRA Uplink

This paper proposes the application of closed-loop type antenna switching transmit diversity (ASTD) associated with frequency domain channel-dependent scheduling to single-carrier frequency division multiple access radio access in the evolved UTRA (UMTS terrestrial radio access) uplink. In the proposed scheme, virtual resource units (RUs) are assigned to the optimum transmitter antenna in the spatial domain, while they are also assigned to the optimum frequency band (i.e., physical RUs) in the frequency domain according to the propagation channel conditions of each user. The reference signal overhead is the same as that for single-antenna transmission and the impact on the hardware implementation in the user equipment is slight since only one RF chain is necessary. Simulation results show that the gain of the closed-loop type ASTD is approximately 1.2-1.5 dB at the 1% level in the cumulative distribution function, assuming unequal antenna gain, i.e., the difference in the average transmission power of 3 dB and the fading correlation between transmitter antennas of 0.3 when frequency domain channel-dependent scheduling is applied with hybrid ARQ and soft-combining.