erent equalization. with ZF suffers from noise enhancement. It is clearly shown that the SC-FDMA MMSE is always preferred to ZF in all simulated conditions. Hence, we will assume MMSE equalization for the following results. 6.6 Impact of Link Adaptation A simple link adaptation technique is adopted in this work [11] in which the link adaptation is defined as the maximum achievable throughput/spectral effi- ciency for various modulations and coding schemes. In this work, the selection of modulation and coding scheme is based on average SNR. The measured SNR at the base station, generally referred to as channel state information (CSI), var- ies depending on the channel condition. Here, the CSI measurement is assumed ideal, whereas in practice it will be influenced by measurement inaccuracy and quantization noise. The spectral efficiency of different MCSs in the single-input, single-output (SISO) case without HARQ is plotted versus the average SNR in Figure 6.12. Variable-rate turbo encoding and modulation from 1/2 BPSK to 16 QAM provide peak data rates from 1.2 to 23 Mb/s for the system with 10-MHz bandwidth. © 2009 by Taylor & Francis Group, LLC Single-Carrier Transmission for UTRA LTE Uplink pi/2 BPSK 1/6 pi/2 BPSK 1/3 QPSK 1/2 QPSK 2/3 QPSK 3/4 8PSK 1/3 8PSK 3/4 16QAM 1/2 16QAM 2/3 16QAM 3/4 16QAM 4/5 SNR (dB) Figure 6.10 Spectral efficiency of SC-FDMA with zero forcing equalization. pi/2 BPSK 1/6 pi/2 BPSK 1/3 QPSK 1/2 QPSK 2/3 QPSK 3/4 8PSK 1/3 8PSK 3/4 16QAM 1/2 16QAM 2/3 16QAM 3/4 16QAM 4/5 SNR (dB) Figure 6.11 Spectral efficiency of SC-FDMA with MMSE equalization. © 2009 by Taylor & Francis Group, LLC Long Term Evolution: 3GPP LTE Radio and Cellular Technology pi/2 BPSK 1/6 pi/2 BPSK 1/3 QPSK 1/2 QPSK 2/3 QPSK 3/4 8PSK 1/3 8PSK 1/2 8PSK 2/3 8PSK 3/4 16QAM 1/2 16QAM 2/3 16QAM 3/4 16QAM 4/5 Link adaptation SNR (dB) Figure 6.12 Spectral efficiency of SISO SC-FDMA with various MCS schemes. In these peak data rates, the 14% pilot overhead described previously has been taken into account. The MCS formats used and