On Timing Reacquisition and Enhanced Primary Synchronization Signal (ePSS) Design for Energy Efficient 3GPP LTE MTC

Machine Type Communications (MTC) is one of the major drivers for the future growth of the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE)/LTE-Advanced (LTE-A) standards. A primary challenge associated with MTC using LTE/LTE-A is to cater to varied requirements of the User Equipment (UE) like coverage enhancement, low complexity, low power consumption, etc. The current LTE/LTE-A standards incorporate the Discontinuous Reception (DRX) mechanism for reduced energy consumption where the UE wakes up periodically to check for a paging message from the base-station. On each wake-up occasion, the UE has to decode the paging information, which requires accurate timing resynchronization. In the case of the MTC UEs, especially when the devices are deployed in low coverage areas, the resynchronization consumes a significant amount of time which increases the ON time of the UE leading to higher energy consumption. In this paper, we introduce the Enhanced Primary Synchronization Signal (ePSS) within the LTE/LTE-A standardization framework and propose a novel DRX mechanism which uses our ePSS for faster resynchronization and reduced energy consumption. We demonstrate that our mechanisms are more energy efficient than the legacy DRX mechanism for the MTC UEs with coverage enhancement.