Power efficient resource mapping techniques and their tradeoffs in LTE Multiple Access

Orthogonal Frequency Division Multiple Access (OFDMA) has become the key physical layer technology for all future wireless standards including LTE, because of its high spectral efficiency and its capacity to combat multipath fading. Inspite of its advantages, one of the major drawbacks of OFDMA system is its high Peak to Average Power Ratio (PAPR) value which is directly related to power consumption of the system. Although power consumption is not a problem for downlink channel, it is one of the main issues for uplink channel because the available power for the mobile user is limited. To overcome this issue, in LTE, for the uplink channel, Discrete Fourier Transform (DFT) spread OFDMA or Single Carrier-FDMA (SCFDMA) system is used. In this paper, we intend to analyze PAPR variation by varying critical parameters of LTE baseband such as number of subcarriers and different modulation and coding schemes. We also examine the power savings and their tradeoffs for resource mapping schemes such as OFDMA, Localized SCFDMA(LFDMA) and Interleaved SCFDMA (IFDMA).