PDCCH Phase Sequence Signaling for Lower PAPR and Blind Decoding
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Solution Overview
Problem
Existing wireless communication systems face challenges in managing peak-to-average power ratio (PAPR) and cubic metric (CM) in physical downlink control channels (PDCCH), which degrade power amplifier efficiency and increase power consumption, particularly for control channels like PDCCH, while selective mapping (SLM) techniques introduce increased signaling overhead and decoding complexity.
Innovation Solution
Implementing phase sequence-based PDCCH transmission using inverse fast Fourier transform (IFFT) and blind decoding, where UEs are pre-configured with phase sequences, allowing for reduced PAPR and CM without explicit signaling of the selected phase sequence, and using a two-stage PDCCH transmission scheme with explicit sequence indication to mitigate decoding complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If selective mapping (SLM) techniques are used to reduce PAPR and CM, then power amplifier efficiency is improved, but signaling overhead and decoding complexity increase
Solution Approach 1:
The patent extracts the phase sequence selection from explicit signaling by using blind decoding at the UE side. The base station selects phase sequences to reduce PAPR/CM, but instead of signaling this selection, the system uses pre-configured UE knowledge and blind decoding to eliminate the need for explicit phase sequence signaling, thereby reducing overhead while maintaining PAPR/CM reduction benefits
Solution Approach 2:
The UE performs blind decoding using pre-configured phase sequences without requiring explicit signaling from the base station. The system leverages the UE's pre-loaded phase sequence knowledge to automatically identify and decode the correct signal, making the system self-sufficient and eliminating the need for additional signaling overhead
2Device complexity
If phase sequence-based transmission with blind decoding is implemented, then signaling overhead is reduced, but decoding complexity at the UE increases
Solution Approach 1:
The patent applies preliminary action by pre-configuring phase sequences at the UE before actual communication. The UE is pre-loaded with multiple phase sequences in advance, so during actual transmission, the UE can directly use these pre-configured sequences for blind decoding without needing to receive or process additional phase sequence information, thereby reducing real-time decoding complexity
3Loss of energy
If multiple phase sequences are generated and selected, then PAPR and CM are reduced, but computational complexity at the base station increases
Solution Approach 1:
The patent applies partial action by generating and evaluating only a subset of possible phase sequences rather than exhaustively testing all possibilities. The base station generates multiple candidate phase sequences and selects the optimal one based on PAPR/CM criteria, but this partial evaluation approach balances performance improvement with acceptable computational complexity
Data Source
AI summary
Various aspects relate to methods, apparatuses, and devices for wireless communication. A base station may modify a set of symbols in a frequency domain by applying a phase sequence to each of one or more symbols for a physical downlink control channel (PDCCH). An inverse fast Fourier transform (IFFT) may be performed on the modified set to obtain a set of signals for PDCCH in a time domain. A signal may be selected from the set based on a criterion comprising one or more of a peak-to-average power ratio (PAPR) value satisfying a threshold, or a cubic metric (CM) value satisfying a threshold. The selected signal may be transmitted over PDCCH to a user equipment (UE), where the UE decodes the signal using blind decoding using phase information or signal-based sequence identification.