PBCH Information Extraction for Reduced System Overhead
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Solution Overview
Problem
The existing LTE PBCH carries a significant amount of information, leading to high system overheads and poor coverage performance due to the inclusion of downlink system bandwidth, PHICH structure information, and system frame number, which results in inefficient resource utilization.
Innovation Solution
The proposed solution involves sending only system frame number (SFN) information on the PBCH, with the option to reduce the number of bits by using longer periods and spreading spectrum techniques, thereby minimizing the information carried and optimizing resource usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the PBCH carries comprehensive information including downlink system bandwidth, PHICH structure information, and system frame number, then the system provides complete configuration information for initial access, but the system overheads increase and coverage performance deteriorates
Solution Approach 1:
The patent extracts only the essential system frame number (SFN) information from the PBCH, removing other configuration information such as downlink system bandwidth and PHICH structure information. This extraction principle reduces the information volume on PBCH from 24 bits to just the SFN, thereby reducing system overheads while maintaining critical functionality for initial access and synchronization.
Solution Approach 2:
The patent segments the broadcast information into different channels: the PBCH carries only SFN information, while other configuration information is transmitted through separate signaling mechanisms. This segmentation allows the PBCH to focus on critical timing information, reducing its overhead and improving coverage performance without losing necessary system configuration capabilities.
2Productivity
If the PBCH carries 24-bit information including SFN, downlink system bandwidth, and PHICH structure information, then the system provides complete configuration data, but the resource occupation increases and efficiency decreases
Solution Approach 1:
The patent applies extraction by removing non-essential information elements from the PBCH, keeping only the SFN. This reduces the information volume from 24 bits to a minimal set, directly improving resource utilization efficiency by freeing up radio resources for other purposes while maintaining the essential timing synchronization function.
3Quantity of substance
If the PBCH transmits minimum information to reduce overheads, then system overheads decrease, but coverage performance on cell edge may be insufficient without proper redundancy
Solution Approach 1:
The patent implements periodic transmission of the reduced PBCH information containing SFN across multiple radio frames. This periodic repetition provides redundancy for cell edge users, allowing them to accumulate sufficient signal energy over multiple periods to successfully decode the broadcast information, thereby maintaining coverage performance despite the reduced information volume.
Solution Approach 2:
The patent changes the transmission parameter by extending the period T beyond one radio frame, allowing the same SFN information to be transmitted repeatedly over an extended time period. This parameter change provides temporal redundancy that improves coverage on cell edge while keeping the instantaneous information volume minimal.
Data Source
AI summary
Embodiments of the present invention disclose a broadcast information sending method, a broadcast information receiving method, a device, and a system, relate to the communications field, and are used to reduce system overheads, and improve coverage performance. The method provided by the embodiments of the present invention includes: sending, by a network device on a physical broadcast channel PBCH, PBCH information to user equipment UE, and sending, by the network device, the PBCH information in a specific radio frame in each period T of the PBCH, where the PBCH information only includes information about a system frame number SFN, and the period T is greater than one radio frame.