Power Scaling Factor Estimation in Interfered LTE Terminals
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Solution Overview
Problem
In LTE communication systems, estimating the power scaling factor for QPSK transmissions is complex, especially in scenarios with strong interference from neighboring base stations, as the scaling factor is typically not communicated, and existing methods struggle to accurately determine it.
Innovation Solution
A communication terminal is equipped with an interference control unit that determines the power scaling factor by receiving signals on different sets of communication resources, assessing interference levels, and using interfering cell scheduling information to select resource blocks where few or no interfering cells are scheduled for data transmission, thereby enhancing estimation accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the terminal estimates the power scaling factor in scenarios with strong interference from neighboring base stations, then the communication performance is improved, but the estimation complexity increases significantly
Solution Approach 1:
The patent segments the estimation process by dividing resource blocks into two categories: those affected by interference and those not affected. The terminal performs separate estimations for each category and combines the results, thereby simplifying the overall estimation complexity while maintaining reliability in interfered scenarios
Solution Approach 2:
The patent introduces an intermediary approach by using resource blocks that are not affected by interference as reference points. These clean resource blocks serve as intermediaries to help estimate the power scaling factor in interfered resource blocks, reducing estimation complexity without sacrificing accuracy
2Device complexity
If the terminal uses traditional estimation methods for power scaling factor, then the device complexity is reduced, but the measurement precision deteriorates in scenarios with strong interference
Solution Approach 1:
The patent applies local quality by treating different resource blocks differently based on their interference characteristics. Resource blocks not affected by interference are used for accurate reference measurements, while those affected by interference are estimated using the reference. This localized approach maintains measurement precision without significantly increasing device complexity
3Loss of information
If the base station communicates the scaling factor for higher modulation orders, then the terminal can accurately determine the power scaling, but for QPSK transmissions the scaling factor is typically not communicated requiring complex estimation
Solution Approach 1:
The patent creates a universal estimation method that works for all modulation types including QPSK. By using resource blocks not affected by interference as universal references, the same estimation approach can be applied regardless of modulation order, avoiding the need for complex QPSK-specific estimation procedures
Data Source
AI summary
A communication terminal is described comprising a receiver configured to receive first signals on a first set of communication resources and to receive a plurality of second signals on a second set of communication resources and an interference control unit configured to determine a level of interference of one or more interferers included in the plurality of second signals and to determine a power scaling factor of signal components of the first signals based on the level of interference by the one or more interferers.