Uplink Control Signaling Prioritization in LTE
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Solution Overview
Problem
In LTE wireless communication systems, the existing methods for transmitting Power Headroom Reports (PHR) and Buffer Status Reports (BSR) can lead to delayed or segmented PHR transmissions, especially during VoIP services, resulting in inefficient modulation and coding scheme adaptations and reduced transmission efficiency due to the higher priority of BSRs over PHRs.
Innovation Solution
A method where the UE checks if the BSR is triggered for an empty uplink transmission buffer and, if so, checks if there is room for a PHR in the uplink resource; if not, it generates and transmits the PHR instead of the BSR, ensuring timely adaptation of the modulation and coding scheme by prioritizing PHR transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If BSR is transmitted with higher priority than PHR, then buffer status information is reported timely, but power headroom report transmission is delayed or segmented
Solution Approach 1:
The patent dynamically adjusts the priority of PHR transmission based on buffer status. When the uplink buffer is empty, PHR priority is increased to replace BSR transmission, ensuring timely power headroom reporting for MCS adaptation while avoiding unnecessary empty BSR transmissions.
Solution Approach 2:
The patent changes the transmission parameter (priority level) of PHR based on buffer conditions. By monitoring whether the buffer is empty or contains data, the system adjusts whether to transmit BSR, PHR, or both, optimizing the timing and content of uplink control information.
2Loss of time
If PHR is transmitted instead of empty BSR, then power headroom information is reported timely, but buffer status reporting function is reduced
Solution Approach 1:
The patent extracts only the necessary control information based on buffer status. When the buffer is empty, only PHR is transmitted since BSR would convey no useful information. When data is present, both BSR and PHR are transmitted to provide complete buffer and power status for optimal scheduling.
Solution Approach 2:
The patent inverts the traditional priority relationship between BSR and PHR under specific conditions. Instead of always prioritizing BSR, the system prioritizes PHR when the buffer is empty, recognizing that power headroom information is more valuable for MCS adaptation in this scenario.
3Reliability
If both BSR and PHR are transmitted when buffer has data, then complete status information is provided, but uplink resource consumption increases
Solution Approach 1:
The patent merges BSR and PHR transmissions into a single uplink opportunity when both are needed. By coordinating their transmission in the same TTI, the system provides complete status information (both buffer and power state) while minimizing the number of separate transmission opportunities required.
Solution Approach 2:
The patent applies partial action by selectively transmitting only the necessary combination of BSR and PHR based on actual buffer conditions. This avoids excessive transmission of redundant information while ensuring that all necessary status information is conveyed for reliable scheduling decisions.
Data Source
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AI summary
A method for transmitting a power headroom report, abbreviated to PHR, and a buffer status report, abbreviated to BSR, for a user equipment in a wireless communication system includes triggering a BSR when a triggering event for the BSR occurs for reporting a status of an uplink transmission buffer of the user equipment to a network of the wireless communication system (402), checking whether the BSR is triggered for reporting that the uplink transmission buffer is empty (404), when the BSR is triggered for reporting the empty uplink transmission buffer, checking whether a PHR is triggered (406) and whether there is room for the PHR in an uplink resource according to a priority order (408), and generating the PHR and transmitting the PHR instead of the BSR to the network when the PHR is triggered and there is not enough room for the PHR in the uplink resource (410).