A. Simonsson, A. Furuskär, Uplink Power Control in LTE - Overview and Performance, Subtitle: Principles and Benefits of Utilizing rather than Compensating for SINR Variations, IEEE 68th Vehicular Technology Conference (VTC 2008-Fall)
There are 6 (I think ) User Equipments( UE) modes in LTE, some of which are not used in the uplink . Some of which also allows up to 64QAM which is usually not used in the uplink. Some choice of modulation and coding scheme and mode the UE is in greatly affects the battery life. see book '' LTE for UMTS: OFDMA and SC-FDMA Based Radio Access '' for detailed modes.