DTX Pattern Configuring Uplink Padding Transmissions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current LTE systems waste UE battery resources and increase uplink interference due to unnecessary PUSCH transmissions when there is no uplink data, and implementing 'fast uplink access' by skipping these transmissions poses operational challenges, including HARQ detection issues, power control problems, and UE recovery difficulties.
Innovation Solution
Configuring wireless communication devices with a Discontinuous Transmission (DTX) pattern to skip uplink padding transmissions during 'off' periods when no data is available in the buffer, while maintaining legacy adaptation algorithms by forbidding skipping during 'on' periods, and aligning DTX with Discontinuous Reception (DRX) patterns to minimize power consumption and signaling impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE sends padding transmissions on PUSCH in uplink grant procedure when no UL data is in buffer, then the eNB can maintain systematic PUSCH transmissions for power control and link adaptation, but this wastes UE battery resources and increases UL interference
Solution Approach 1:
The patent introduces periodic Discontinuous Transmission (DTX) patterns that alternately enable and disable PUSCH transmissions during configured grants. These periodic on/off cycles allow the system to maintain occasional systematic transmissions for power control and link adaptation while significantly reducing overall transmission activity, thereby conserving UE battery resources and reducing uplink interference during off-periods.
Solution Approach 2:
The patent makes the PUSCH transmission behavior dynamic by introducing configurable DTX patterns that can be activated or deactivated based on system conditions. The dtx-Pattern configuration allows the UE to dynamically switch between transmitting and skipping PUSCH transmissions, enabling adaptive balance between maintaining system reliability through periodic transmissions and conserving energy by skipping transmissions during off-periods.
2Loss of energy
If the UE skips PUSCH transmissions when no UL data is in buffer, then UE battery efficiency improves and UL interference decreases, but the eNB cannot reliably perform PUSCH DTX detection and HARQ operations
Solution Approach 1:
The patent applies preliminary action by configuring the UE with DTX patterns and associated parameters (dtx-Pattern, dtx-UL-Grant-Delay, dtx-UL-Grant-Offset) before the UE actually skips transmissions. This pre-configuration allows the eNB to anticipate when DTX will occur and prepare appropriate HARQ processes and detection mechanisms, enabling reliable HARQ operation despite skipped transmissions.
Solution Approach 2:
The patent implements feedback mechanisms where the eNB monitors and detects DTX conditions based on the configured patterns and provides appropriate responses through downlink control channels. The feedback loop allows the eNB to track which transmissions were skipped and adjust HARQ retransmissions accordingly, maintaining reliable HARQ detection even when transmissions are skipped during off-periods.
3Loss of time
If configured uplink grants are allocated for every subframe to enable fast uplink access, then uplink transmission latency is reduced, but the UE sends only padding transmissions most of the time
Solution Approach 1:
The patent applies periodic action by introducing DTX patterns that create regular on/off cycles for PUSCH transmissions. During on-periods, the UE can transmit immediately when data arrives, maintaining low latency. During off-periods, the UE skips transmissions when no data is present, avoiding battery waste from padding transmissions while still being ready to transmit instantly when data becomes available.
Solution Approach 2:
The patent applies local quality by making the transmission behavior different in different time periods. During on-periods of the DTX pattern, the system maintains aggressive transmission behavior for low latency. During off-periods, it switches to conservative behavior to save energy. This local differentiation allows the system to optimize for different objectives at different times.
4Loss of energy
If PUSCH transmissions are skipped during configured grants, then battery efficiency improves, but there is no confirmation to the eNB that PDCCH indicating UL grant was correctly received
Solution Approach 1:
The patent uses the DTX pattern configuration and associated control parameters as an intermediary mechanism to convey transmission intentions from UE to eNB. By pre-configuring and acknowledging the DTX pattern parameters, the UE and eNB establish a shared understanding of when transmissions will occur and when skipping is expected, eliminating the need for explicit PDCCH acknowledgment during skipped periods.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A User Equipment has an uplink buffer for storing uplink data to be sent to a base station in an uplink grant procedure and is configured with a DTX (Discontinuous Transmission) pattern which allows it to skip the transmission of uplink padding transmissions when there is a grant but no uplink data in the uplink buffer during 'off' periods.