Sounding Resource Assignment in TDD Cellular Networks
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Solution Overview
Problem
In wireless communication networks, especially in LTE TDD systems, the limited sounding resources lead to partial or coarse channel state information (CSI) availability at the access point (AP), which affects downlink performance due to a large number of user equipment (UEs) competing for limited feedback capacity, while only some UEs contribute significantly to system throughput.
Innovation Solution
The solution involves dynamically assigning sounding resources to UEs based on channel information, prioritizing those with better channel conditions to optimize spectrum utilization and maximize beamforming performance, thereby ensuring that UEs with higher path gain or lower interference are allocated sounding resources, ensuring accurate CSI acquisition and improved downlink performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sounding resources are allocated to all UEs, then each UE can obtain channel state information, but the limited sounding capacity results in partial or coarse CSI for each UE
Solution Approach 1:
The patent applies local quality by differentiating the treatment of different UEs based on their channel conditions. UEs with good channel conditions (high path gain, low interference) receive full sounding resource allocation for accurate CSI, while UEs with poor channel conditions receive reduced or no sounding resources, as their contribution to system throughput is minimal. This selective allocation resolves the contradiction by optimizing measurement precision for UEs where it matters most.
Solution Approach 2:
The patent changes the parameter of sounding resource allocation dynamically based on channel conditions. The allocation is not fixed but adapts to varying path gain and interference levels. By adjusting the sounding resource allocation parameter according to real-time channel quality, the system achieves high CSI accuracy for beneficial UEs while conserving limited sounding capacity, thus resolving the contradiction between measurement precision and quantity of UEs served.
2Reliability
If more sounding resources are allocated, then downlink performance improves, but the limited radio resources constrain the number of UEs that can be accommodated
Solution Approach 1:
The patent applies local quality by allocating sounding resources selectively to UEs with good channel conditions who contribute significantly to system throughput. By focusing resources on UEs where downlink performance improvement translates to meaningful system throughput gain, the patent resolves the contradiction between reliability (downlink performance) and productivity (system throughput), achieving both through targeted resource allocation.
Solution Approach 2:
The patent applies partial action by allocating full sounding resources only to a subset of UEs with excellent channel conditions, rather than distributing limited resources uniformly across all UEs. This partial allocation to high-value UEs achieves disproportionate system throughput improvement, resolving the contradiction by concentrating resources where they yield maximum productivity while maintaining reliability for critical UEs.
3Ease of operation
If sounding resources are distributed uniformly, then resource allocation is simple, but channel spectrum utilization is suboptimal
Solution Approach 1:
The patent transforms the static uniform resource allocation into a dynamic allocation scheme that adapts to channel conditions. The sounding resource allocation changes based on real-time path gain and interference measurements, allowing the system to optimize spectrum utilization efficiently. This dynamic approach resolves the contradiction between ease of operation and spectrum utilization efficiency by automating the optimization process.
Solution Approach 2:
The patent implements feedback mechanisms where UEs report channel quality indicators (CQI) and path gain information, which the base station uses to adjust sounding resource allocation. This feedback loop enables the system to automatically optimize spectrum utilization without complex manual configuration, resolving the contradiction between ease of operation and spectral efficiency by using feedback-driven automated resource management.
Data Source
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AI summary
The embodiments disclose a method and an an Access Point (AP) for assigning a sounding resource in a Time Division Duplex (TDD) cellular network. The method obtains a channel information between a serving AP and a User Equipment (UE) served by the serving AP, determines whether to assign the sounding resource to the UE according to the predetermined assigning criteria based on the channel information, and makes the sounding resource assignment if it is determined to assign the sounding resource to the UE.