SC-FDMA Uplink System In Heavily Faded Areas With Low Signal-To-Noise Ratio

Abstract

These Single carrier frequency division mul- tiple access (SC-FDMA) has very low power consump- tion at the sender’s side, and it is the access scheme used for the uplink in long-term evolution (LTE). The objective of this work is to explore the error proba- bility of SC-FDMA system under sub-carrier mapping (SM) in heavily faded areas where the signal-to-noise ratios (SNRs) are very low. Wireless environment with heavily faded areas includes military radio systems; di- rect sequence spread spectrum system (DS-SS), global positioning system (GPS) etc. The localized FDMA (LFDMA) and distributed FDMA (DFDMA) are used to compare the performances of SC-FDMA in heavily faded areas. In heavily faded area with negative signal- to-noise ratio (SNR), the SC-FDMA system is imple- mented using modulation and encoding methods to re- ceive a very weak signal. Here, binary phase shift key- ing (BPSK), quadrature phase shift keying (QPSK), 16-PSK, quadrature amplitude modulation (QAM) and 16-QAM modulation techniques are used to calculate the bit error rate (BER) performances. The results show the BER performances of SC-FDMA using map- ping schemes for different channels, like, AWGN chan- nel, Rayleigh channel, COST207TU, and COST207RA channel models for heavily faded areas. In AWGN channel, BER at -15dB is about 10 times more than BER at 15dB. The COST207 model shows that the BER is less in typical urban (TU) area compared to the rural area (RA).The performance of BPSK modu- lation in SC-FDMA system is better in heavily faded areas than other modulation schemes.