R-PDCCH Search Space Design Using Distributed Resource Units
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Solution Overview
Problem
Current wireless communication systems face challenges in designing an efficient search space for the Relay Physical Downlink Control Channel (R-PDCCH) in relay-based networks, particularly in maintaining similar transmission efficiency and minimizing control information transmission between base stations and relay nodes.
Innovation Solution
The method involves allocating a contiguous sequence of transmission resource units for control information, rearranging them to form a physically distributed sequence, and transmitting control information using a portion of the rearranged units, which enhances frequency diversity and selectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If control information is transmitted using a contiguous sequence of transmission resource units, then the transmission structure is simple and easy to implement, but frequency diversity and selectivity are limited
Solution Approach 1:
The patent segments the contiguous sequence of transmission resource units into multiple sub-sequences or groups, which are then distributed across different frequency resources. This segmentation allows the control information to be transmitted across multiple frequency segments, thereby improving frequency diversity while maintaining a structured and implementable transmission framework.
Solution Approach 2:
The patent transforms the one-dimensional contiguous sequence of transmission resource units into a multi-dimensional distribution pattern by mapping the segmented units across different frequency resources and potentially different time slots. This dimensional transformation enables frequency diversity gain while preserving the simplicity of the original contiguous allocation structure through systematic mapping rules.
2Reliability
If control information is transmitted using a physically distributed sequence of transmission resource units, then frequency diversity is enhanced, but the transmission structure becomes more complex
Solution Approach 1:
The patent applies preliminary action by pre-defining the distribution pattern and mapping rules for the transmission resource units before actual transmission. The contiguous sequence is pre-segmented and pre-mapped to distributed frequency resources using systematic algorithms, which reduces the complexity during real-time transmission while ensuring frequency diversity is achieved through the predetermined distribution structure.
3Reliability
If more transmission resource units are allocated for control information, then control information transmission reliability is improved, but transmission overhead increases
Solution Approach 1:
The patent merges the transmission of control information with data transmission by allocating control information to the same physical downlink shared channel resources used for data. The control information is multiplexed with data in the time-frequency grid, allowing simultaneous transmission of both control and data information without requiring separate dedicated resources, thereby improving reliability while minimizing additional overhead.
Data Source
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AI summary
Certain aspects of the present disclosure provide methods and apparatus for designing, generating, and monitoring the search space for control information for a node, such as a relay node (RN). This control information may comprise a Relay Physical Downlink Control Channel (R-PDCCH). The search space design may use contiguous, but physically distributed transmission resource units (e.g., physical resource blocks (PRBs)) to increase frequency diversity or frequency selectivity. For certain aspects, pairs of transmission resource units spanning two adjacent slots may have the same virtual resource block (VRB) index.