System-Level Throughput Evaluations in Evolved UTRA

This paper presents simulation results on the achievable spectrum efficiency, user throughput, and peak data rate in the orthogonal frequency division multiplexing (OFDM) based evolved UTRA (E-UTRA) downlink and single-carrier frequency division multiple access (SC-FDMA) based uplink in order to clarify the link-level performance gain of E-UTRA compared to high-speed downlink packet access (HSDPA) and enhanced DCH (E-DCH). The simulation results show that in the OFDM based downlink, the spectrum efficiency is increased to approximately 230% compared to that for HSDPA at the activity factor of approximately 0.6-0.8, and that the user throughput at the cumulative distribution function (CDF) of 5% and the average user throughput are increased to greater than 200 and 300%, respectively, compared to those for HSDPA at the spectrum efficiency of less than 0.6 bps/Hz. Moreover, in the SC-FDMA based uplink, the spectrum efficiency of E-UTRA is improved to approximately 190% compared to that for E-DCH, and the user throughput at the CDF of 5% and average user throughput are greater than 200% that of E-DCH. In the downlink employing 2-by-2 multiple-input multiple-output (MIMO) multiplexing with a 20-MHz transmission bandwidth, the target peak data rate of 100 Mbps is achieved at the average received signal energy per symbol-to-noise power spectrum density ratio (E_s/N₀) of approximately 23.5 dB using 64QAM and turbo coding with R=3/4 employing QRM-MLD, i.e., maximum likelihood detection using QR decomposition and the M-algorithm, with adaptive selection of surviving symbol replica candidates (ASESS). Furthermore, in the uplink assuming single-antenna transmission and two-branch antenna diversity reception, the target peak data rate of 50 Mbps is achieved at the average received E_s/N₀ of approximately 23 dB using 16QAM associated with the coding rate of R=8/9