OFDM Resource Mapping for Spatial Multiplexing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current LTE systems face challenges in efficiently allocating resources for uplink ACK/NACK channels and control channels, particularly in supporting spatial multiplexing and minimizing inter-cell interference, which limits the ability to configure channels effectively for high-speed data communication services.
Innovation Solution
A resource mapping method and apparatus that allocates dedicated control resources using resource indices and Dedicated Reference Signal (DRS) port indices, allowing for dynamic resource sharing and improved efficiency by mapping the dedicated control channel region into the data channel region, enabling independent spatial distribution of uplink ACK/NACK resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If control channel is configured using legacy LTE method mapping to individual CCEs, then uplink ACK/NACK channel can be allocated, but spatial multiplexing and beamforming capabilities are not supported
Solution Approach 1:
The patent introduces a new dimension for resource allocation by using Resource Element Groups (REGs) instead of the traditional Control Channel Element (CCE) structure. This dimensional change allows the control channel to be configured in a way that supports spatial multiplexing and beamforming while maintaining compatibility with uplink ACK/NACK channel allocation. The REG-based structure enables independent spatial distribution of control channel resources across different antenna ports and beams.
Solution Approach 2:
The control channel is segmented into multiple Resource Element Groups (REGs) that can be independently allocated and mapped to different spatial layers. This segmentation allows the control channel to be distributed across multiple antennas and beams, enabling spatial multiplexing capabilities while maintaining the ability to allocate corresponding uplink ACK/NACK resources.
2Productivity
If control channel resources are extended by spatial multiplexing, then multi-antenna and beamforming are supported, but resource allocation for uplink ACK/NACK channel becomes impossible using legacy methods
Solution Approach 1:
The patent creates a universal resource allocation mechanism that works for both legacy LTE systems and LTE-Advanced systems with spatial multiplexing. By using REG-based indexing and maintaining the mapping principle from downlink control resources to uplink ACK/NACK resources, the system achieves multi-functionality that supports both traditional and advanced features simultaneously.
Solution Approach 2:
The patent introduces REG indices as an intermediary parameter that bridges the gap between spatially multiplexed control channels and uplink ACK/NACK resource allocation. The REG index serves as a common reference point that allows the system to allocate uplink resources even when downlink control channels are distributed across multiple spatial layers.
3Object-affected harmful factors
If ICIC technique is applied to control channel, then inter-cell interference is reduced, but resource distribution across system bandwidth becomes less flexible
Solution Approach 1:
The patent implements dynamic resource allocation where REGs can be flexibly assigned to different cells and users based on interference conditions and traffic requirements. The REG-based structure allows the system to dynamically adjust the distribution of control channel resources across the system bandwidth while maintaining ICIC benefits, as REGs can be selectively allocated to minimize inter-cell interference rather than following fixed patterns.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method and apparatus for allocating resource between uplink ACK/NACK channel and downlink control channel supporting spatial multiplexing in an OFDM-based wireless communication system which configures uplink ACK/NAK channel implicitly using reference signals for discriminating among resource allocation spaces and physical channel resource. The method is capable of multiplexing the uplink ACK/NACK channel associated with the control channel extended by spatial multiplexing into the uplink ACK/NACK channel resource which does not support spatial multiplexing.