Hello @rafaeldamasio,
The handset makers and network vendors are doing a big ‘task force’, a ‘work in progress’ to maximize the power efficiency of LTE devices (and avoid battery drastic drain). These efforts are very important, mainly because future technologies like LTE-Advanced will also have an even bigger hunger for power.
One big advance was the development of Envelope Tracking technology, that help a lot in this battle (although many improvements ‘needs to’ and ‘can be’ still made).
Here you can find an explanation of Envelope Tracking:
BR,
Leo