TDD UL-DL Configuration Timing Alignment in Carrier Aggregation
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Solution Overview
Problem
Wireless communication systems face inefficiencies in transmitting and receiving signals in multicarrier systems supporting Time Division Duplex (TDD), particularly in configuring signal transmission and reception timing, which hinders effective carrier aggregation and leads to misalignment between base stations and user equipment.
Innovation Solution
A method for configuring a first cell with a first TDD UL-DL configuration and a second cell with a second TDD UL-DL configuration, where the relationship among subframes is determined based on a specific TDD UL-DL configuration with the smallest number of UL subframes, allowing for efficient reuse of existing signal transmission/reception timing in a multicarrier system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If different TDD UL-DL configurations are used for carrier aggregation, then system adaptability and resource utilization are improved, but timing misalignment between base station and user equipment occurs
Solution Approach 1:
The patent introduces a reference configuration as an intermediary between the first and second TDD UL-DL configurations. This reference configuration serves as a mediator to establish timing relationships, allowing the system to utilize different configurations for carrier aggregation while maintaining timing alignment through the reference framework.
Solution Approach 2:
The patent changes the timing parameters (K and L values) based on the specific configuration scenario. By dynamically adjusting these parameters according to whether the second cell is configured as UL or DL in the reference configuration, the system adapts timing relationships to resolve misalignment issues while maintaining configuration flexibility.
2Device complexity
If existing signal transmission/reception timing is reused, then device complexity is reduced, but timing misalignment in multicarrier TDD systems occurs
Solution Approach 1:
The patent applies local quality by treating different cells differently based on their configuration. The first cell uses one timing relationship while the second cell uses another timing relationship derived from the reference configuration. This localized approach allows reuse of existing timing mechanisms while adapting to specific cell requirements, reducing overall complexity without sacrificing alignment.
3Productivity
If subframe allocations are optimized for different TDD configurations, then resource utilization is improved, but timing coordination between cells becomes complex
Solution Approach 1:
The patent segments the timing coordination problem by introducing a reference configuration that is separate from the actual data transmission configurations. This segmentation allows each cell to have optimized subframe allocations for its specific TDD configuration while the reference configuration handles the timing coordination, dividing the complexity into manageable parts.
Data Source
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AI summary
The present invention relates to a wireless communication system. More particularly, the present invention relates to a method for transmitting an uplink signal in a wireless communication system supporting a carrier merge, and comprises the steps of: setting a first cell having a first TDD UL-DL configuration and a second cell having a second TDD UL-DL configuration; receiving a PHICH signal in a subframe #(n-L) of the first cell, or receiving a PDCCH signal in a subframe #(n-K) of the first cell; and transmitting a PUSCH signal in a subframe #n of the second cell, corresponding to the PHICH signal or the PDCCH signal, wherein the relationship between the subframes #(n-L), #(n-K), and #n is determined in consideration of a parameter value set in a specific TDD UL-DL configuration inside a TDD UL-DL configuration set, and the specific TDD UL-DL configuration is the TDD UL-DL configuration having the least number of UL subframes from one or more TDD UL-DL configurations, in which subframes set as UL in the first cell or the second cell are all set as ULs.