Back-to-back Reference Signal Allocation for Interference Cancellation
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Solution Overview
Problem
In wireless communication systems, overlapping reference signal resource elements from neighboring base stations can lead to signal degradation and reduced throughput due to inefficient interference cancellation, especially in mixed data and reference signal interference within small control regions.
Innovation Solution
A base station selects contiguous sets of reference signal resource elements and performs interference cancellation based on an interference covariance matrix, coordinating with neighboring base stations to prevent partial overlap and optimize resource element groups for control signaling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If reference signal REs are transmitted using standard allocation methods, then channel estimation can be performed, but overlapping reference signals from neighboring base stations cause interference cancellation inefficiency and signal degradation
Solution Approach 1:
The patent applies asymmetry by using back-to-back reference signal allocation where the first reference signal is allocated to a first antenna port and the second reference signal is allocated to a second antenna port with contiguous REs. This asymmetric allocation pattern creates distinguishable interference characteristics that enable more effective interference cancellation at the UE, resolving the contradiction between maintaining channel estimation accuracy and reducing neighboring cell interference.
Solution Approach 2:
The patent changes the parameter of reference signal RE allocation from standard distributed patterns to contiguous back-to-back allocation. Specifically, the first set of REs for the first antenna port and the second set of REs for the second antenna port are allocated contiguously in the frequency domain. This parameter change transforms the interference structure into a form that can be more effectively cancelled, improving reliability while reducing harmful interference effects.
2Reliability
If interference cancellation is performed on control messages, then signal quality improves, but coordination complexity between base stations increases
Solution Approach 1:
The patent segments the control channel resources by allocating specific REs for reference signals associated with specific antenna ports. By dividing the control region into distinct reference signal allocations for different antenna ports with back-to-back contiguous REs, the system enables targeted interference cancellation for control messages without requiring complex full-system coordination, thus improving signal quality while managing coordination complexity through structured resource segmentation.
3Productivity
If resource elements are allocated for both reference signals and control signaling, then resource utilization improves, but partial overlap reduces interference cancellation effectiveness
Solution Approach 1:
The patent applies local quality by creating specific local patterns within the control region where reference signal REs for different antenna ports are allocated contiguously. This local back-to-back structure ensures that within each control resource element group, the reference signals have distinguishable patterns that enable effective interference cancellation, while still allowing overall high resource utilization by efficiently packing control and reference signal resources without excessive guard bands or wasted REs.
Data Source
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AI summary
Methods, systems, and devices for wireless communication are described. A base station may select a two sets of reference signal resource elements (REs) for a symbol period, where each RE of the first set is contiguous to an RE of the second set. The base station may also identify resource element groups (REGs) for control signaling, where each REG covers one or more resource blocks (RBs). The base station may then perform interference cancellation, which may be based on an interference covariance matrix for each of the REGs. In some cases, the base station may coordinate with neighboring base stations (directly or through the core network) to ensure that the selected REGs do not partially overlap with reference signal transmissions or REGs of neighboring base stations.