Uplink Reference Signal Allocation for Mobile Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current mobile communication systems face challenges in managing co-channel interference, particularly in dense deployments, where the limited number of orthogonal reference signals required for channel estimation reduces available uplink resources for data transmission, leading to decreased system capacity and signal quality.
Innovation Solution
A method where a network node allocates orthogonal reference signals to a subset of antenna ports based on channel quality, prioritizing those with better channel conditions, allowing fewer than the maximum required orthogonal reference signals while ensuring each user equipment has at least one allocated, thereby optimizing resource allocation and minimizing performance degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of orthogonal reference signals is reduced, then uplink resources for data transmission are increased, but channel estimation accuracy and signal quality deteriorate
Solution Approach 1:
The patent applies local quality by differentiating the treatment of antenna ports based on their channel quality. Instead of uniformly allocating reference signals to all antenna ports, the system identifies and prioritizes antenna ports with better channel conditions (lower path loss) for reference signal allocation. This selective approach ensures that reference signals are concentrated on antenna ports that can provide more reliable channel estimation, thereby maintaining measurement precision while reducing the total number of reference signals needed.
2Reliability
If orthogonal reference signals are allocated to all antenna ports, then channel estimation reliability is improved, but available uplink resources for data transmission are reduced
Solution Approach 1:
The patent extracts the essential function of channel estimation by allocating reference signals only to a selected subset of antenna ports rather than all antenna ports. By taking out the non-essential allocations (reference signals to antenna ports with poor channel quality), the system maintains sufficient channel estimation reliability for the most important antenna ports while freeing up significant uplink resources for data transmission. This extraction principle directly resolves the contradiction between reliability and resource quantity.
3Reliability
If the maximum number of orthogonal reference signals is allocated, then system performance is optimized, but interference from reference signals increases
Solution Approach 1:
The patent applies partial action by allocating reference signals to only the necessary subset of antenna ports rather than the maximum number. By providing just enough reference signals to maintain acceptable channel estimation performance (partial action rather than full allocation), the system reduces reference signal interference while preserving sufficient system performance. This partial allocation strategy eliminates the excessive reference signal transmissions that would otherwise create harmful interference.
Data Source
Figure 1a~1b
Figure 2a
Figure 2b
AI summary
A mobile communication system network node (NN) that serves user equipments (UEs) has fewer orthogonal reference signals (RSs) than a maximum number of UE antenna ports (APs) that can be served by the NN. A channel quality of a channel between the AP and the network node is ascertained for each of the APs. Whenever a number of APs of UEs served by the NN exceeds the number of RSs, all RSs are allocated to a subset of all of the APs by means of an allocation process such that: each RS is allocated to only one of the APs; each AP has no more than one RS allocated to it; and allocation decisions are a function of the channel qualities of the respective APs such that the higher the channel quality, the higher priority the corresponding AP is given as a candidate for receiving an RS allocation.