Noise Rise Estimation for Cell Stability in Interference Whitening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for noise rise estimation in wireless communication systems, particularly those using interference whitening techniques like GRAKE+ or chip equalizers, face challenges in providing reliable load measurements for cell stability due to changes in the thermal noise floor and increased computational complexity, limiting the utilization of interference cancellation gains.
Innovation Solution
A method and arrangement for noise rise estimation that measures received total wideband power, generates own cell power measures, estimates noise floor and neighbour cell interference, and calculates a noise rise measure using combining weights and code power to interference ratio, allowing for reliable load scheduling with reduced computational power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If interference whitening techniques (GRAKE+, chip equalizers) are used to reduce interference levels, then the useful signal power and capacity are improved, but the thermal noise floor changes and computational complexity increases, making reliable load measurement difficult
Solution Approach 1:
The patent segments the load measurement process into multiple components: measuring received total wideband power separately, generating own cell power measures separately, estimating noise floor independently, and calculating noise rise as a distinct derived parameter. This segmentation allows each component to be measured and processed independently, maintaining accuracy despite interference whitening operations.
Solution Approach 2:
The patent performs preliminary measurements of received total wideband power and generates own cell power measures before the interference whitening process affects the signal. By capturing these baseline measurements in advance, the system can later compute noise floor and noise rise parameters that accurately reflect the load condition, even after interference whitening modifies the signal characteristics.
2Productivity
If interference whitening is applied to reduce interference, then capacity and signal quality improve, but computational power requirements increase
Solution Approach 1:
The patent extracts the essential load measurement information (received total wideband power and own cell power measures) from the signal before interference whitening processing. By taking out these critical measurements at an earlier stage when the signal is still in its original form, the system avoids the need for complex computations on the already-processed interference-whitened signal, thereby reducing computational power requirements while maintaining measurement accuracy.
3Device complexity
If conventional load estimation methods are used in interference cancellation receivers, then implementation is simpler, but the full amount of resources and link gains cannot be utilized
Solution Approach 1:
The patent introduces an intermediary measurement approach that bridges conventional load estimation methods and interference cancellation receiver requirements. By measuring received total wideband power and own cell power as intermediate quantities that can be derived from available receiver outputs, the system enables accurate load estimation without requiring fundamental changes to the interference cancellation architecture, thus maintaining simplicity while enabling full resource utilization.
Data Source
AI summary
A noise rise estimation method calculates (230) a noise rise measure suitable for stability control purposes, based at least on a useful signal power for the first user after interference whitening, a first user noise floor compensation factor, a code power to interference ratio measure for the first user, a noise floor measure and an estimated neighbour cell interference power. These factors are provided by measuring (210) received total wideband power and generating (212) a measure of an own cell power. An estimate of the noise floor measure is computed (214) and the neighbour cell interference power is estimated (216) based on these measurements and generated measures. An interference whitening is performed (220). The useful signal power for the first user after interference whitening is determined (222). The first user noise floor compensation factor is derived (224) based on combining weights for the first user used in for the first user is obtained (226).