SRS Bandwidth Allocation in UpPTS Subframes
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Solution Overview
Problem
Current wireless communication systems, particularly in LTE-A, inefficiently utilize uplink pilot time slot (UpPTS) bandwidth for sounding reference signals (SRS) transmissions, limiting the maximum SRS bandwidth available to non-root user equipment (UEs) due to PRACH format 4 data allocation, leading to suboptimal channel estimation and potential collisions.
Innovation Solution
The method determines whether available uplink bandwidth for the UpPTS portion is greater than for a normal uplink subframe and allocates extra bandwidth to non-root UEs for SRS transmissions, allowing them to use the maximum available UpPTS bandwidth, excluding PRACH format 4 data, thereby enhancing SRS transmission efficiency and avoiding collisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If SRS transmissions are allocated in UpPTS portion, then channel estimation can be performed, but available uplink bandwidth is limited due to PRACH format 4 data allocation
Solution Approach 1:
The patent implements dynamic bandwidth allocation for SRS transmissions by determining whether all SRS transmissions occur in UpPTS and comparing available bandwidth between UpPTS and normal uplink subframes. The system adapts the SRS transmission bandwidth based on real-time conditions, selecting the maximum available bandwidth from either UpPTS or normal uplink subframe, thereby resolving the contradiction between limited UpPTS bandwidth and channel estimation requirements.
2Productivity
If maximum SRS bandwidth is selected according to UL RBs and PRACH in UpPTS, then bandwidth utilization is optimized, but non-root UEs experience suboptimal channel estimation
Solution Approach 1:
The patent applies local quality by providing differentiated SRS transmission opportunities for different UE types. Non-root UEs are specifically enabled to transmit SRS in normal uplink subframes when UpPTS bandwidth is insufficient, while root UEs can utilize UpPTS. This localized adaptation ensures that each UE type receives appropriate bandwidth allocation for channel estimation based on its specific requirements and constraints.
3Reliability
If SRS transmissions occur in UpPTS, then uplink pilot functionality is achieved, but collisions with PRACH format 4 data may occur
Solution Approach 1:
The patent introduces an intermediary decision-making mechanism that compares available bandwidth in UpPTS versus normal uplink subframes. When UpPTS bandwidth is insufficient or collisions are detected, the system mediates by redirecting SRS transmissions to normal uplink subframes, thereby avoiding collisions with PRACH format 4 data while maintaining uplink pilot functionality through alternative transmission paths.
Data Source
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AI summary
A method for enhancing a sounding reference signal (SRS) in a non-root wireless communication device is disclosed. The method determines that all SRS transmissions for the wireless communication device are to occur in an uplink pilot time slot (UpPTS) portion of a transition subframe. The method also determines whether available uplink bandwidth for the UpPTS portion is greater than available uplink bandwidth for a normal uplink subframe. A current SRS is transmitted using the available uplink bandwidth for UpPTS portion when the available uplink bandwidth for the UpPTS portion is greater than available uplink bandwidth for the normal uplink subframe.