Dual Frame Boundaries for Low-Latency RACH and PUSCH Timing

The patent divides the single UL frame boundary into two separate boundaries: one for RACH processing and one for PUSCH processing. This segmentation allows each channel to have its own timing reference, eliminating the latency-induced conflicts that occur when using a shared frame boundary. The RACH boundary can be independently positioned to accommodate roundtrip latency requirements without affecting PUSCH processing.

The patent introduces dynamic timing adjustment through the timing advance mechanism. Instead of statically increasing the number of root-sequences to compensate for latency, the system dynamically adjusts the RACH frame boundary timing based on actual latency conditions. This allows the system to maintain RACH performance with fewer root-sequences by adapting the timing reference point rather than expanding the sequence set.

The patent extracts the timing reference for RACH processing from the PUSCH frame boundary, separating the timing functions into independent references. This extraction allows the RACH boundary to be positioned optimally for each remote antenna unit regardless of fiber length, enabling accurate timing even over extended fiber reaches without being constrained by the PUSCH timing resolution or ZCZ configuration limits.