Control Channel Scrambling Sequence for Inter-Cell Interference Reduction
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Solution Overview
Problem
Existing wireless communication systems face challenges in reducing interference between cells due to insufficient randomization and scrambling of control channels, particularly in LTE and NR technologies, which affect the decoding of downlink control information.
Innovation Solution
Implementing techniques for enhanced CCE-to-REG mapping and PDCCH scrambling that include applying a shift to the mapping process and using a simplified scrambling sequence based on configurable identifiers and time-domain parameters, irrespective of interleaved or non-interleaved mappings, to increase randomization and reduce interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing control channel scrambling methods are used, then the system maintains simplicity in implementation, but interference between cells remains high and randomization is insufficient
Solution Approach 1:
The patent changes the parameters used in scrambling sequence generation by introducing a time-domain parameter (slot index) in addition to the cell identifier. This creates a more complex scrambling sequence that varies over time and across cells, thereby reducing interference between cells while maintaining implementation feasibility through standardized parameter modifications.
2Reliability
If control channels are scrambled with cell identifiers, then decoding can be performed, but processing resources are consumed and randomization is limited
Solution Approach 1:
The patent introduces dynamic elements to the scrambling process by incorporating the slot index as a time-varying parameter. This makes the scrambling sequence dynamic rather than static, allowing the system to maintain decoding reliability through proper synchronization while reducing processing resources by using a more efficient randomization approach that leverages time-domain variation.
3Object-affected harmful factors
If search space randomization is insufficient, then the system is easier to implement, but interference between adjacent cells increases
Solution Approach 1:
The patent segments the control channel resources by introducing cell-specific and UE-specific search spaces with distinct scrambling sequences. This segmentation allows different cells and UEs to use different scrambling patterns, reducing inter-cell interference while maintaining manageable complexity through structured organization of search spaces.
Solution Approach 2:
The patent applies preliminary randomization actions by pre-configuring cell identifiers and slot indices before the actual data transmission. This preliminary setup enables the scrambling sequence to be determined in advance, reducing the complexity of real-time processing while achieving effective randomization that minimizes interference between adjacent cells.
Data Source
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AI summary
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless communication device may determine a scrambling sequence for a control channel, wherein the scrambling sequence is determined using a same identifier irrespective of whether the control channel is associated with a cell radio network temporary identifier (C-RNTI) or another type of RNTI, and wherein the scrambling sequence is determined based at least in part on an identifier associated with the wireless communication device and a value associated with an RNTI of the wireless communication device; and transmit or receive the control channel.