Contention Window Adjustment via HARQ-ACK DTX States

The patent changes the parameter used for contention window adjustment from simple ACK/NACK counting to a more sophisticated method that incorporates DTX detection and signal strength measurement. By measuring the received power of HARQ-ACK signals and comparing against thresholds, the system can distinguish between collisions and channel errors, enabling more accurate channel access decisions while maintaining manageable complexity through standardized threshold comparisons

The patent replaces the mechanical counting method (simply counting ACK/NACK signals) with a signal processing approach that measures received power levels and compares them against predefined thresholds. This substitution allows for more nuanced detection of collision versus error conditions by utilizing the physical layer signal characteristics rather than just higher-layer protocol information

The patent performs preliminary action by pre-defining power thresholds for distinguishing collisions from channel errors before actual data transmission occurs. These thresholds are established in advance based on system characteristics and are stored for quick reference during operation, eliminating the need for complex real-time calculations and reducing processing time while maintaining high reliability

The patent implements a feedback mechanism where the measured received power of HARQ-ACK signals is continuously monitored and compared against predefined thresholds. This feedback loop enables the system to quickly determine whether a signal represents a collision or channel error, allowing for rapid adjustment of contention window sizes and retransmission decisions without significant processing delays