Question: What determines the accuracy of sub-band Channel Quality Indicator (CQI) reporting in frequency-selective interference conditions?
Option 1: Average signal-to-noise ratio (SNR) across all sub-bands.
Option 2: The number of sub-bands with high reported differential CQI offset levels.
Option 3: A percentile of the reported differential CQI offset level +2 for a preferred sub-band, and relative increase in throughput when transmitting on a randomly selected sub-band among those with the highest reported differential CQI offset levels.
Option 4: The total bandwidth of the frequency-selective interference.
Explanation: This option is correct because it accurately reflects the information provided. The accuracy of sub-band Channel Quality Indicator (CQI) reporting under frequency-selective interference conditions is indeed determined by a percentile of the reported differential CQI offset level +2 for a preferred sub-band, and the relative increase in throughput when transmitting on a randomly selected sub-band among those with the highest reported differential CQI offset levels. This ensures that preferred sub-bands are used for frequency-selective scheduling under such conditions, optimizing network performance.