Uplink Interference Cancellation in Wireless Base Stations
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Solution Overview
Problem
In advanced wireless communication systems like LTE, base stations face challenges in distinguishing desired uplink signals from interfering signals, leading to decoding failures due to high interference power, particularly in the blind nature of interference sensing where crucial parameters like the number of dominant interferers and their PRB allocations are difficult to estimate.
Innovation Solution
A method and apparatus for uplink interference suppression and cancellation, where a base station identifies interfering uplink signals and performs interference suppression or cancellation by estimating interference-related parameters, reconstructing interference signals, and subtracting them from the received signal, using techniques like subspace-based interference sensing and interference map construction to prioritize and suppress or cancel interfering signals effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the base station receives uplink signals from multiple user equipment simultaneously, then the network capacity and throughput are improved, but the interference level increases making it difficult to distinguish desired signals from interfering signals
Solution Approach 1:
The patent segments the received uplink signal into multiple components: desired signal, interfering signals, and noise. By identifying and separating these components through interference sensing and parameter estimation, the base station can process each component differently, enabling successful decoding of desired signals even in high-interference environments with multiple simultaneous transmissions.
2Productivity
If the base station attempts to decode uplink data signals in high interference environments, then the network utilization is improved, but the decoding success rate decreases due to high interference power
Solution Approach 1:
The patent performs preliminary interference sensing and parameter estimation before attempting to decode the desired uplink signal. By identifying interfering signals, estimating their parameters (power, spectral characteristics), and constructing interference models in advance, the base station prepares cancellation templates that are then applied during the decoding process, significantly improving decoding success rate in high-utilization scenarios.
3Adaptability or versatility
If the base station performs blind interference sensing to identify interfering signals, then the ability to handle unknown interference patterns is improved, but the complexity of estimating interference parameters increases
Solution Approach 1:
The patent transforms the complex parameter estimation problem into a more manageable form by changing the parameters being estimated. Instead of directly estimating all interfering signal parameters simultaneously, the system iteratively estimates key parameters (interference power, spectral occupancy, cyclic prefix length) and uses these to refine the interference model, reducing the overall estimation complexity while maintaining adaptability.
Data Source
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AI summary
A base station includes a transceiver and processor. The transceiver receives an uplink signal from each of a plurality of user equipment. UEs comprise desired UEs each with a desired uplink signal and at least one interfering UE with an interfering uplink signal interfering with the received uplink signals. The processor identifies a set of interfering uplink signals from the at least one interfering UE. The set includes at least one interfering uplink signal. The at least one interfering uplink signal overlaps with at least one PRB of the desired uplink signal. The processor identifies one or more subsets of interfering uplink signals from the identified set of interfering uplink signals based on one or more metrics each of which is a function of parameters of the interfering uplink signals. The processor performs interference suppression or interference cancellation on at least one of the one or more identified subsets.