Frequency Domain Channel-Dependent Scheduling Employing an Adaptive Transmission Bandwidth for Pilot Channel in Uplink Single-Carrier-FDMA Radio Access

This paper proposes frequency and time domain channel-dependent scheduling employing an adaptive transmission bandwidth for the pilot channel for channel quality indication (CQI) measurement in the uplink single-carrier (SC)-FDMA radio access. In the proposed scheme, a high multiuser diversity effect due to frequency domain channel-dependent scheduling is gained by assigning a wide pilot transmission bandwidth to user equipments (UEs) near a cell site, whereas the influence of the CQI measurement error is mitigated by assigning a narrow pilot transmission bandwidth to UEs near the cell boundary at the cost of utilizing multiuser diversity in the frequency domain. System simulation results elucidate that the cell throughput using the adaptive pilot transmission bandwidth with the predetermined threshold, TH
_SINR
of -6 dB is increased by approximately 600 kbps compared to that using a fixed 1.25-MHz pilot transmission bandwidth, i.e., only time domain channel-dependent scheduling, owing to an increasing multiuser diversity effect in the frequency domain. We also show that the user throughput using the adaptive pilot channel transmission bandwidth scheme at a 5% cumulative distribution function is increased by approximately 35 and 30% compared to that using a 5-MHz transmission for 16 and 32 UEs per cell, respectively, for the inter-site distance of 500 m