Radio Link Adaptation Using Long-Term Power Level Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communications networks, the combination of link quality variations and aged link quality estimates leads to inaccurate channel quality estimates, which can result in transmission failures, especially for delay-sensitive services with stringent residual error rate requirements.
Innovation Solution
The method involves pre-allocating channel quality measurement resources for neighboring network nodes to transmit signals of long-term power levels, which are functions of instantaneous power levels across multiple time and frequency resources. The User Equipment (UE) performs channel quality measurements on these signals and reports a Channel Quality Indicator (CQI) to the first network node, allowing it to adapt the radio link for transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If link quality estimates are used with aging to account for channel variations, then adaptability to changing conditions is improved, but measurement precision deteriorates leading to inaccurate channel quality estimates
Solution Approach 1:
The patent applies preliminary action by having neighboring network nodes transmit signals with known long-term power levels in advance on dedicated measurement resources. This allows the UE to measure and report accurate long-term interference levels before actual data transmission occurs, resolving the contradiction between adaptability and measurement precision by preparing accurate reference data ahead of time.
2Measurement precision
If measurement resources are allocated for instantaneous interference measurement, then measurement precision is improved, but loss of time increases due to measurement delays
Solution Approach 1:
The patent uses preliminary action by pre-allocating dedicated channel quality measurement resources where neighboring nodes transmit signals with long-term power levels. This allows the UE to obtain accurate long-term interference measurements in advance without delaying actual data transmission, as the measurement resources are prepared beforehand and do not interfere with the main data flow.
3Reliability
If margin is increased for link quality estimates to account for interference variations, then reliability is improved, but productivity deteriorates due to reduced throughput
Solution Approach 1:
The patent applies feedback by having the UE measure actual long-term interference levels on dedicated resources and report these measurements back to the network node. The network node then uses this feedback information to set appropriate transmission parameters and margins, achieving both reliability and productivity by basing margin selection on actual measured conditions rather than using excessive conservative margins.
Data Source
AI summary
A method performed by a first network node for adapting a radio link to a User Equipment, UE, served by the first network node in a wireless communications network is provided. Respective channel quality measurement resources are pre-allocated for each 5 of one or more neighbouring network nodes for transmitting respective signals of one or more long-term power levels. The long-term power levels are functions of instantaneous power levels of more than one time and frequency resource of a radio link. The first network node configures (601) the UE to perform a channel quality measurement of the signals which are transmitted using the one or more long-term power 10 levels by the one or more neighbouring network nodes in the pre-allocated channel quality measurement resources. The first network node receives (602) a report from the UE. The report reports a first Channel Quality Indicator, CQI. The first CQI is calculated based on a channel quality measurement performed on the signals of the one or more long-term power levels 15 according to the configuration. The first network node then adapts (603) the radio link for a transmission to the UE based on the received first CQI.