Dynamic Carrier Switching for Frequency Diversity in DC-HSDPA
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Dual-cell high speed downlink packet access (DC-HSDPA) in wireless communications limits frequency diversity due to fixed mapping of high speed downlink shared channels to physical channel resources, restricting the benefits of multiple downlink carriers.
Innovation Solution
A method and apparatus that allow wireless transmit/receive units (WTRUs) to dynamically switch between downlink carriers at specific boundaries, such as the high speed shared control channel (HS-SCCH) or high speed physical downlink shared channel (HS-PDSCH) subframes, enabling frequency diversity gains by reassigning HARQ retransmissions across different carriers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fixed mapping of HS-DSCH to physical channel resources is used, then HARQ retransmissions are simplified, but frequency diversity benefits are restricted
Solution Approach 1:
The patent implements dynamic mapping between HS-DSCH and physical resources, allowing the system to adapt carrier assignments based on channel conditions. The mapping is no longer fixed but can be reconfigured to exploit frequency diversity while maintaining manageable HARQ complexity through controlled dynamic adjustment.
Solution Approach 2:
The system changes the mapping parameters between transport channels and physical resources dynamically. By modifying which carrier an HS-DSCH maps to based on observed channel quality and diversity conditions, the system achieves frequency diversity benefits without overwhelming complexity.
2Adaptability or versatility
If dynamic mapping between HS-DSCH and physical resources is implemented, then frequency diversity benefit is improved, but system complexity increases
Solution Approach 1:
The system performs preliminary configuration of multiple carriers and their potential mappings before actual data transmission. By pre-establishing the pool of available carriers and their characteristics, the system reduces the complexity of real-time dynamic mapping decisions while still achieving frequency diversity benefits.
3Device complexity
If single downlink carrier reception is used, then receiver design is simplified, but network efficiency is limited
Solution Approach 1:
The receiver is designed with multi-functionality to handle both single-carrier and multi-carrier operations. By making the receiver universal and capable of operating with one or multiple downlink carriers, the system achieves improved network efficiency through carrier aggregation while maintaining simplified operation modes when needed.
Data Source
AI summary
A method and an apparatus for utilizing multiple carriers are disclosed. A wireless transmit/receive unit (WTRU) capable of receiving on a single downlink carrier at a time may tune the receiver to one downlink carrier and switch the downlink carrier in accordance with a configured pattern. The WTRU may switch the carrier from an anchor carrier to a non-anchor carrier at a high speed shared control channel (HS-SCCH) sub-frame boundary, and switches back at an end of a subsequent high speed physical downlink shared channel (HS-PDSCH) subframe. The WTRU may switch the carrier at an HS-PDSCH sub-frame boundary. A WTRU capable of receiving on multiple downlink carriers simultaneously may tune the receiver to an anchor carrier and a supplementary carrier, and switch the supplementary carrier to another carrier based on a carrier switching order. The carrier switching order may be received via an HS-SCCH or via layer 2 signaling.