PBCH Beam Hopping for Lower Sweep Overhead in 5G NR
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Solution Overview
Problem
Current 5G New Radio (NR) systems face challenges in reducing beam sweep overhead and energy consumption for Physical Broadcast Channel (PBCH) transmissions, while also efficiently transmitting system information and enhancing PBCH performance.
Innovation Solution
The method involves determining a PBCH beam hopping pattern and adjusting it based on the direction distribution of wireless transmit/receive units (WTRUs), using a concatenated master information block with cyclic redundancy check (CRC) bits and polar encoding for efficient channel coding and transmission, and employing beam hopping and full beam sweeping techniques to optimize energy usage and latency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If full beam sweeping is used for PBCH transmission to ensure coverage, then reliability is improved, but energy consumption and beam sweep overhead increase
Solution Approach 1:
The patent implements dynamic beam sweeping where the beam sweeping pattern and frequency are adjusted based on WTRU direction distribution patterns. The system transitions from static full beam sweeping to dynamic adaptive beam hopping, where beams are swept more frequently in directions with higher WTRU density and less frequently in directions with lower density, thereby reducing overall energy consumption while maintaining reliability.
Solution Approach 2:
The system changes the beam sweeping parameters (frequency, pattern, duration) based on detected WTRU direction distribution. By monitoring WTRU locations and adjusting beam sweeping parameters accordingly, the system optimizes the balance between coverage reliability and energy consumption, sweeping beams more aggressively in high-demand directions and conserving energy in low-demand directions.
2Speed
If beam sweep frequency is increased to reduce latency, then speed is improved, but energy consumption increases
Solution Approach 1:
The patent applies dynamic adjustment of beam sweep frequency based on service requirements and WTRU distribution. High-priority services or directions with concentrated WTRUs receive higher beam sweep frequencies to reduce latency, while low-priority directions use lower frequencies to conserve energy, creating a dynamic balance between speed and energy consumption.
Solution Approach 2:
Different beam sweep frequencies are applied to different spatial directions based on local WTRU distribution characteristics. Directions with high WTRU density or high service priority receive faster beam sweeping (higher frequency), while directions with low density receive slower sweeping, optimizing the local quality of service in each direction without uniformly increasing energy consumption across all directions.
3Use of energy by moving object
If beam hopping pattern is optimized for energy efficiency, then energy consumption is reduced, but system information transmission efficiency may worsen
Solution Approach 1:
The system uses feedback from WTRU direction distribution detection to continuously optimize the beam hopping pattern. By monitoring where WTRUs are located and adjusting the beam hopping sequence accordingly, the system ensures that system information is transmitted efficiently to actual users while maintaining energy-efficient hopping patterns that avoid unnecessary beam sweeps in empty directions.
Solution Approach 2:
The system performs preliminary detection of WTRU direction distribution before finalizing the beam hopping pattern. This preliminary action allows the system to pre-optimize the beam hopping sequence to match expected WTRU locations, ensuring both energy efficiency and transmission efficiency are optimized before actual PBCH transmission begins.
Data Source
AI summary
A method for transmitting system information on a PBCH is described herein. A transmission/reception point (TRP) may generate a concatenated master information block (MIB) transport block that includes information bits associated with system bandwidth information, timing information, system frame number (SFN), a beam sweeping configuration, and a control resource set (CORESET). The TRP may then attach at least 16 cyclic redundancy check (CRC) bits to the concatenated MIB and then prioritize the concatenated MIB and the at least 16 CRC bits based on content. The TRP may then perform channel coding of the prioritized concatenated MIB and the at least 16 CRC bits to produce coded bits using at least one polar encoder with a coding rate that is less than 1/3, perform rate matching via repetition on the coded bits, and then transmit the rate matched, coded bits on the PBCH of a radio frame.