Cross-BWP Uplink Frequency Hopping RF Retuning Gap Timing

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Solution Overview

Problem

Existing wireless communication systems, particularly for NR-light UEs, face challenges in performing cross-BWP uplink frequency hopping due to difficulties in determining the RF retuning gap, leading to increased punctured symbols, dropped transmissions, and reduced transmit diversity.

Innovation Solution

A method and apparatus for determining an RF retuning gap between frequency hops in uplink transmissions by calculating the starting and ending symbols based on the starting symbol of the second hop and the gap duration, allowing for proper RF retuning during the gap to minimize punctured symbols and improve transmission reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If RF retuning gap is not properly determined for cross-BWP uplink frequency hopping, then transmission reliability deteriorates with increased punctured symbols and dropped transmissions, but determining the RF retuning gap increases calculation complexity

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidcalculation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-defining the RF retuning gap parameters (starting symbol and length) based on the second hop's starting symbol. This allows the UE to calculate the retuning gap position in advance before actual frequency hopping occurs, ensuring proper RF retuning time is allocated without increasing runtime calculation complexity. The formula starting_symbol_RF_retuning_gap = starting_symbol_second_hop - length_RF_retuning_gap provides a deterministic calculation that resolves the contradiction between ensuring reliability and maintaining simplicity.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If RF retuning gap duration is increased to allow proper retuning, then transmission reliability improves, but time resources for actual data transmission are reduced

Engineering Contradiction:
Improvetransmission reliabilityVSAvoiddata transmission efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the RF retuning gap length parameter based on the specific frequency hop configuration. The length_RF_retuning_gap is configured to be the minimum necessary duration for RF retuning, rather than using a fixed conservative value. This optimized parameter setting ensures sufficient retuning time for reliability while maximizing the remaining time for actual data transmission, thus resolving the contradiction between reliability and productivity.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If RF retuning is performed during cross-BWP frequency hopping, then frequency switching capability is improved, but punctured symbols increase causing transmission losses

Engineering Contradiction:
Improvefrequency switching capabilityVSAvoidtransmission data loss
Core Design Contradiction:
Adaptability or versatilityVSLoss of substance

Solution Approach 1:

The patent applies preliminary action by calculating and reserving the RF retuning gap position before frequency hopping occurs. By determining the starting symbol and length of the retuning gap in advance based on the second hop's parameters, the system ensures that RF retuning is performed in a pre-allocated time window that does not overlap with data transmission symbols. This prevents symbol puncturing and transmission losses while maintaining the frequency switching capability needed for cross-BWP hopping.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4085717B1Determining an RF retuning gap for cross-BWP uplink frequency hopping
Publication Date: 2026.03.25 QUALCOMM INC
  • EP4085717B1 patent drawingFigure 1
  • EP4085717B1 patent drawingFigure 2
  • EP4085717B1 patent drawingFigure 3A

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may determine a starting symbol of a radio frequency (RF) retuning gap between a first plurality of repetitions of an uplink transmission in a first frequency hop and a second plurality of repetitions of the uplink transmission in a second frequency hop. The starting symbol of the RF retuning gap is based at least in part on a starting symbol of the second plurality of repetitions and a quantity of symbols included in the RF retuning gap. The UE may determine an ending symbol of the RF retuning gap based at least in part on the starting symbol of the second plurality of repetitions. The UE may perform RF retuning during the RF retuning gap. Numerous other aspects are provided.