Power efficient uplink LTE with CPM-SC-IFDMA

Power efficiency represents a key concern in the mobile communication field. Poor power efficiency leads to shorter battery life and increases the cost of the mobile device. Improving power efficiency is more important for uplink transmission since in uplink the transmitter is placed in the battery-powered mobile device which has limited power resources. In this paper we propose a power efficient scheme, CPM-SC-IFDMA, for uplink transmission in LTE (Long Term Evolution). The proposed scheme, CPM-SC-IFDMA, combines the key advantages of CPM (continuous phase modulation) with SC-IFDMA (Single Carrier Frequency Division Multiple Access with Interleaved subcarrier mapping) in order to increase the power amplifier efficiency of the transmitter. In this work, we investigate the bit error rate (BER) performance of the proposed scheme in LTE specified channels. The BER performance of the CPM-SC-IFDMA scheme is compared with that of a LTE specified transmission scheme, QPSK-LFDMA (QPSK modulated SC-FDMA with localized subcarrier mapping), combined with convolutional coding (CC-QPSK-LFDMA). We first show that CPM-SC-IFDMA has a much higher power efficiency than CC-QPSK-LFDMA by simulating the PAPR (peak-to-average-power-ratio) plots. Then, using the data from the PAPR plots and the conventional BER plots (BER as a function of signal-to-noise-ratio), we show that, when compensated for power efficiency loss CPM-SC-IFDMA has a superior performance relative to CC-QPSK-LFDMA by up to 3.8 dB in the LTE specified channels.