Group-Wised Reference Signal Allocation for Single-Carrier FDMA Radio Access in Evolved UTRA Uplink

This paper proposes a group-wised reference signal (RS) for channel quality indicator measurement in frequency domain channel-dependent scheduling employing adaptive control of the transmission bandwidth in the single-carrier frequency division multiple access-based evolved UMTS terrestrial radio access uplink. In the proposed method, fluctuation in the interference power imparted to the surrounding cells is suppressed to a low level, and both the user throughput for a user equipment (UE) near the cell edge and the cell throughput are improved compared to the conventional uniform RS allocation due to reductions in the error when selecting the optimum UE in channel-dependent scheduling and selecting the modulation and coding scheme in the adaptive modulation and channel coding. Simulation results show that the user throughput at the 5% cumulative distribution function value when employing the proposed group-wised sounding RS allocation with the adaptive transmission bandwidth is increased by approximately 75% and 65% for the inter-site distance of 500 and 1732 m, respectively, compared to that using a uniform RS allocation, while achieving almost the same level of cell throughput.