Two-Stage Wake-Up Receiver for LTE Battery Conservation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In Long Term Evolution (LTE) wireless communication systems, user equipment (UE) experiences significant battery power drain due to continuous monitoring of the Physical Downlink Control Channel (PDCCH), leading to reduced battery life, especially when data is not scheduled for transmission during the Connected Discontinuous Reception (C-DRX) mode, resulting in wasteful energy consumption and potential performance losses from stale channel state information.
Innovation Solution
Implementing a multi-stage wake-up process that conditionally transitions UE receivers from low power operation to communication ready operation, where a pre-wake up stage monitors for control signals to determine if a full wake-up process is warranted, thereby avoiding unnecessary power consumption by skipping the wake-up process when no data is expected.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE performs continuous PDCCH monitoring in C-DRX mode, then the UE is ready to receive and transmit data, but the battery power is drained heavily
Solution Approach 1:
The wake-up process is divided into two distinct stages: a first stage that performs essential warm-up operations (RF and baseband) and a second stage that performs additional operations (channel estimation, synchronization) only if data is actually present. This segmentation allows the UE to perform minimal operations when no data is expected, reducing power consumption while maintaining readiness when needed.
Solution Approach 2:
The UE performs preliminary warm-up operations (RF warm-up and baseband warm-up including AGC, TTL, FTL, and channel estimation) before the scheduled ON duration to ensure it is ready to receive data immediately when the ON duration begins. This preliminary action eliminates the need for continuous monitoring while maintaining data reception readiness.
2Reliability
If the UE wakes up earlier to perform RF and baseband warm-up, then the UE is fully ready for data reception, but the power consumption increases significantly
Solution Approach 1:
The wake-up process is segmented into a first stage (RF and baseband warm-up) that always occurs, and a second stage (channel estimation, synchronization, and other operations) that occurs only if data is detected during the ON duration. This allows the UE to perform essential preparation operations while avoiding unnecessary additional operations when no data is present.
Solution Approach 2:
The UE performs a partial wake-up process (first stage only) when no data is expected, and a complete wake-up process (both stages) when data is present. This partial action approach avoids the excessive power consumption of always performing the full wake-up process while maintaining adequate readiness for data reception.
3Measurement precision
If the UE performs full wake-up process every ON duration, then channel state information is always fresh, but power is wasted when no data is transmitted
Solution Approach 1:
The wake-up process is divided into two stages: the first stage performs essential warm-up operations, and the second stage performs channel estimation and synchronization operations only if data is detected during the ON duration. This segmentation ensures fresh channel state information is obtained only when necessary, avoiding wasted power during idle periods.
Solution Approach 2:
The system uses feedback from the detection of data during the ON duration to determine whether to proceed with the second stage of the wake-up process. If data is detected, the UE performs channel estimation and synchronization; if no data is detected, the UE skips these operations, optimizing power consumption based on actual communication needs.
Data Source
AI summary
Systems and method of embodiments herein operate to conserve battery power of user equipment (UE). Embodiments determine whether waking up a UE receiver would be beneficial and based on the determination, the UE either wakes up the receiver or returns to sleep. Embodiments determine whether to wake up the receiver by performing pre-wake up (PWU) operation which either wakes up the receiver in a low power mode or wakes up the UE's wake up receiver. It may be determined whether a wake up (WU) signal is received during a PWU stage. If a WU signal is received during the PWU stage the UE may perform a full wake up of the receiver. If a WU signal is not received the UE may return to idle mode. In embodiments, WU (Wake Up) DRX cycles are supplemented with a Full DRX (Discontinuous Reception) cycle.