Frequency Selective SINR Regeneration in Wireless Networks
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Solution Overview
Problem
In communication systems, particularly in TDD systems, narrow frequency domain granularity for channel quality indicators (CQIs) leads to increased overhead and longer adaptation times, degrading the performance of link adaptation and other communicative operations due to asymmetric allocation of uplink and downlink timeslots and non-reciprocal interference.
Innovation Solution
A device estimates frequency-selective signal-to-interference-plus-noise ratios (SINRs) at a finer frequency level using wideband CQIs, improving link adaptation and scheduling with minimal overhead by calculating SINR estimates for each frequency unit, enabling more precise communicative operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If narrow frequency domain granularity for CQI is used, then link adaptation performance is improved, but overhead increases and adaptation time increases
Solution Approach 1:
The patent segments the frequency domain into multiple sub-bands, allowing CQI feedback to be provided at a finer granularity level. This segmentation enables more precise link adaptation per sub-band while managing the overhead through selective reporting mechanisms, thus resolving the contradiction between measurement precision and time loss.
Solution Approach 2:
The system performs preliminary channel quality measurements and predictions to anticipate channel conditions. By using prediction algorithms and preliminary assessments, the system can prepare link adaptation parameters in advance, reducing the actual adaptation time while maintaining precision.
2Measurement precision
If narrow frequency domain granularity for CQI is used, then link adaptation performance is improved, but overhead increases
Solution Approach 1:
The patent applies local quality by allowing different CQI reporting granularities for different sub-bands based on their specific characteristics. Only sub-bands requiring fine-grained control report detailed CQI information, while others use broader granularity. This reduces overall overhead while maintaining link adaptation performance where it matters most.
Solution Approach 2:
The system uses partial action by selectively reporting CQI information for only certain sub-bands rather than all sub-bands. This partial reporting approach reduces overhead while still providing sufficient information for effective link adaptation in the most critical frequency regions.
3Quantity of substance
If wideband CQI is used in TDD systems with high asymmetry, then overhead is reduced, but frequency selective link adaptation performance degrades
Solution Approach 1:
The patent implements dynamic CQI reporting where the granularity and frequency of CQI feedback adapt based on channel conditions, traffic patterns, and system state. During periods of high mobility or interference, finer granularity is activated; during stable conditions, broader granularity suffices. This dynamic approach balances overhead reduction with performance maintenance.
Data Source
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AI summary
A method is performed by a device in a wireless network. The method includes receiving a transmission that includes a wideband channel quality indicator, determining a received signal power estimate for each frequency band of a frequency domain, and determining an average interference-plus-noise based on the wideband channel quality indicator and the received signal power estimate. The method further includes determining a signal-to- interference-plus-noise ratio estimate for each frequency band based on the average interference- plus-noise and the received signal power estimate, and performing a communicative operation based on the signal-to-interference-plus-noise ratio estimate.