Distributed DTX Alignment with Memory

This paper addresses the assignment of transmission and sleep time slots between interfering transmitters with the objective of minimal power consumption. In particular, we address the constructive alignment of Discontinuous Transmission (DTX) time slots under link rate constraints. Due to the complexity of the combinatorial optimization problem at hand, we resort to heuristic assignment strategies. We derive four time slot alignment solutions (sequential alignment, random alignment, p-persistent ranking and DTX alignment with memory) and identify trade-offs. One solution, DTX alignment with memory, addresses trade-offs of the other three by maintaining memory of past alignment and channel quality to buffer short term changes in channel quality. All strategies are found to exhibit similar convergence behavior, but different power consumption and retransmission probabilities. DTX alignment with memory is shown to achieve up to 40% savings in power consumption and more than 20% lower retransmission probability than the state of the art.Comment: 13 pages, In 2014 IEEE International Conference on Communications (ICC), Page(s): 3481 - 348

Energy Efficient TransmissionTechniques for LTE

The goal of the European ICT ProjectEARTH is to enhance energy efficiency of cur-rent LTE cellular networks by 50 percent,enabling operators to provide more extensivecoverage, namely to less densely populatedareas, while ensuring high levels of efficiency,hence, reducing the carbon footprint. In order toachieve this objective, different strategies, at dif-ferent levels, are being addressed. Energy effi-cient transmission techniques for LTE, proposedwithin the framework of EARTH, are addressedand discussed, with an emphasis on beamform-ing and MIMO. It is concluded that the strategicobjective of EARTH is achievable. CombinedMIMO mode selection, resource allocation,scheduling and precoding strategies will allow anenergy consumption reduction of more than 50percent in macro-cells. A reduction in MIMOpower consumption of 91.7 percent (factor of12) can be achieved in pico-cellsinfo:eu-repo/semantics/publishedVersio