PHICH Timing for TDD-FDD Carrier Aggregation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Establishing accurate timing for transmitting and receiving physical hybrid ARQ indicator channels (PHICH) in uplink data transmission is challenging when carriers operating in different duplex modes are aggregated, particularly for primary cells (PCell) and secondary cells (SCell) with different duplex modes, affecting the overall efficiency of wireless communication networks.
Innovation Solution
The method involves self-carrier scheduling and cross-carrier scheduling for PCell and SCell operating in various duplex modes, including TDD and FDD, to establish PHICH timing for PUSCH transmission and reception, ensuring accurate control information exchange and HARQ-ACK operations across different duplex modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If carriers operating in different duplex modes (TDD and FDD) are aggregated for carrier aggregation, then data transmission capacity is improved, but timing establishment for PHICH transmission becomes complex and ambiguous
Solution Approach 1:
The patent applies local quality by establishing separate timing relationships for TDD and FDD carriers. Specifically, for a TDD PCell, the PHICH timing follows TDD uplink-downlink configuration rules (e.g., PHICH transmitted in downlink subframe n+k for uplink data in subframe n), while for an FDD SCell, the PHICH timing follows FDD rules (e.g., PHICH transmitted in downlink subframe n+4 for uplink data in subframe n). Each carrier type maintains its own timing characteristics locally, resolving the complexity of unified timing establishment.
Solution Approach 2:
The patent segments the timing establishment process into distinct rules for TDD and FDD carriers. The base station separately determines PHICH transmission timing for TDD PCell versus FDD SCell, and the terminal separately monitors PHICH on each carrier type according to their respective timing rules. This segmentation allows independent optimization of timing for each duplex mode without mutual interference.
2Productivity
If cross-carrier scheduling is implemented between TDD PCell and FDD SCell, then control channel efficiency is improved, but PHICH timing synchronization becomes difficult
Solution Approach 1:
The patent uses the TDD PCell as an intermediary for cross-carrier scheduling of the FDD SCell. The PCell transmits uplink grants for SCell data transmission, and the terminal transmits uplink data on the SCell based on these grants. For PHICH timing, the patent establishes that when cross-carrier scheduling is used, the PHICH timing follows the scheduling cell's (PCell's) timing rules, with appropriate offset adjustments to account for the SCell's FDD characteristics. This intermediary approach maintains control efficiency while achieving timing synchronization.
3Measurement precision
If separate PHICH timing is established for each carrier type, then timing accuracy for each carrier is improved, but overall system coordination becomes complex
Solution Approach 1:
The patent establishes a universal PHICH timing determination framework that works for both TDD and FDD carriers. The base station determines PHICH timing based on the carrier type (TDD or FDD) and applies the corresponding timing rule from a unified set of predefined relationships. The terminal universally monitors PHICH according to the timing determined by the base station, using the same decision logic regardless of carrier type. This universal approach maintains timing accuracy while simplifying system coordination through standardized procedures.
Data Source
AI summary
Provided are a method and an apparatus for setting timing of a response information transmission channel for uplink transmission of a terminal configured with cells operating in different duplex modes. Provided are also a method and an apparatus for setting timing for receiving a response signal in a terminal that performs communications through one or more cells operating in different duplex modes. The method may include setting both the PCell and the SCell to be self-carrier scheduled, receiving control information for PUSCH transmission from the PCell or the SCell, transmitting the PUSCH at the PCell or the SCell on the basis of the control information, and receiving a PHICH for the PUSCH transmitted on the basis of the PHICH timing of the PCell or SCell in accordance with the PUSCH transmission from the PCell or the SCell.