Question: In a multi-user PUCCH scenario, what does the DTX (Discontinuous Transmission) to ACK (Acknowledgement) probability primarily indicate?
Option 1: The likelihood of successful data transmission in the presence of multiple users.
Option 2: The probability of detecting an ACK when no signal is transmitted on the desired channel but interfering signals are present.
Option 3: The rate at which a base station switches between DTX and ACK modes to conserve power.
Option 4: The minimum required Signal-to-Interference Ratio (SIR) for reliable ACK detection in multi-user environments.
Explanation: This metric accurately describes the likelihood of correctly detecting an acknowledgement when no signal is intentionally sent on the primary channel, yet interference from other signals is present, crucial for evaluating the robustness and reliability of acknowledgement detection in noisy, multi-user wireless environments.