Base Station Uplink Resource Scheduling for Passive Interference Cancellation
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Solution Overview
Problem
Existing methods for passive interference cancellation in wireless communication systems, such as PIMC, face inefficiencies due to the need for frequent retraining of interference estimators caused by non-linearity and time variance in radio systems, leading to short-lived effectiveness and reduced cancellation efficiency.
Innovation Solution
A resource scheduling method at the base station to identify and schedule user equipment (UE) for stable passive interference cancellation by determining UE's passive interference cancellation capability and consecutively assigning uplink resources to maintain effective interference estimation for a predefined period, thereby stabilizing interference and enhancing cancellation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the searching step in LMS algorithm is increased to speed up convergence, then convergence speed is improved, but the algorithm frequently misses convergence and reliability deteriorates
Solution Approach 1:
The patent applies dynamics by making the step size adaptive rather than fixed. The LMS algorithm dynamically adjusts its step size based on the current estimation error and signal statistics, allowing it to take larger steps when far from convergence and smaller steps when close, thereby achieving both fast convergence and high reliability without missing convergence points
2Reliability
If the searching step in LMS algorithm is decreased to improve convergence reliability, then reliability is improved, but convergence speed becomes slower
Solution Approach 1:
The patent resolves this contradiction by implementing a dynamic step size adjustment mechanism. The algorithm starts with a larger step size to achieve fast initial convergence, then automatically reduces the step size as convergence approaches, ensuring both speed and reliability are optimized at different stages of the convergence process
3Measurement precision
If UE frequently retrains the interference estimator to track time variation, then tracking accuracy is improved, but the effectiveness period of each training becomes shorter and overall efficiency deteriorates
Solution Approach 1:
The patent applies periodic action by scheduling interference estimator retraining at optimized intervals rather than continuously or too frequently. The base station determines appropriate retraining periods based on interference stability and channel conditions, allowing the estimator to remain effective for longer periods while still tracking time variations when necessary
Solution Approach 2:
The patent changes the parameter of retraining frequency from fixed/high to adaptive/optimized. By adjusting the retraining interval based on actual interference characteristics and channel conditions, the system achieves a balance between tracking accuracy and cancellation efficiency, avoiding unnecessary retraining that would reduce overall productivity
4Power
If the radio system operates with non-linear components to enable signal transmission, then transmission capability is improved, but passive interference such as PIM is generated
Solution Approach 1:
The patent converts the harmful passive interference generated by non-linear components into a beneficial effect by using the interference estimator to model and cancel the interference. The same non-linear components that generate PIM are also the source of the interference signal that can be estimated and subtracted, turning the harmful effect into a manageable and cancelable disturbance
Data Source
AI summary
Embodiments of the present disclosure provide methods and apparatuses for resource scheduling. A method at a base station comprises determining a passive interference cancellation capability of a User Equipment (UE) having a passive interference issue. The passive interference is coupled into a receive path of the UE from a transmission of at least one signal through a transmit path of the UE. The method further comprises scheduling at least one uplink resource for the UE based on the passive interference cancellation capability.