LTE-TDD System Information Window Configuration for Reliable Delivery
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Solution Overview
Problem
The current LTE standard for system information acquisition in TDD networks is suboptimal, leading to blocked or partially blocked transmission windows due to UL subframes, resulting in incomplete or impossible SI message delivery to user equipment, especially with certain frame configurations, which affects the reliability and availability of system information.
Innovation Solution
The solution involves configuring the SI message transmission windows to account for TDD frame configurations, ensuring that SI messages are transmitted with equal reliability by adjusting the SI-window length and starting point calculations to avoid overlap with UL subframes, allowing for consistent and robust SI message delivery across different frame configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the current LTE standard procedure is used for SI message transmission in TDD networks, then the transmission window may be blocked by UL subframes, but this leads to incomplete or impossible SI message delivery
Solution Approach 1:
The patent changes the parameters of SI message transmission by adjusting the SI-window length and starting point calculations based on TDD frame configurations. Specifically, it modifies the subframe offset calculation to account for the number of downlink subframes in each radio frame, ensuring that SI messages are transmitted only in downlink subframes and not blocked by UL subframes.
Solution Approach 2:
The patent introduces dynamic adjustment of SI transmission windows based on TDD frame configurations. The SI-window length and starting position are dynamically calculated according to the specific TDD frame type (e.g., type 0, type 1, type 2, type 3, type 4, type 5, type 6), allowing the system to adapt to different frame structures and avoid UL subframe blockages.
2Ease of manufacture
If a fixed SI-window length is used for all TDD frame configurations, then the system is simple to implement, but certain frame configurations result in blocked transmission windows
Solution Approach 1:
The patent changes the SI-window parameters (length and starting point) based on TDD frame configuration types. Different frame configurations (type 0-6) have different numbers of downlink subframes, and the patent adjusts the SI-window accordingly to ensure it fits within available downlink subframes without being blocked by UL subframes.
Solution Approach 2:
The patent applies different SI transmission window configurations for different TDD frame types. Each frame configuration type (0-6) has specific local characteristics in terms of downlink and uplink subframe distribution, and the patent tailors the SI-window parameters to match each local configuration, ensuring reliable transmission in each specific scenario.
3Productivity
If SI messages are transmitted without considering TDD frame configurations, then the transmission procedure is simple, but transmission windows are blocked by UL subframes resulting in unequal reliability
Solution Approach 1:
The patent changes the transmission parameters by calculating the SI-window starting point and length based on the specific TDD frame configuration. This ensures that all SI messages, regardless of their order in the scheduling information list, are transmitted with equal reliability by avoiding UL subframe blockages through configuration-aware parameter adjustment.
Data Source
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AI summary
A network element for a cellular communication system comprises a signal processing logic module arranged to: generate a single system information message; generate a variable si-Windowlength parameter for transmission to the at least one wireless communication unit; and determine availability for downlink transmissions to the at least one wireless communication unit. The network element further comprises a transceiver arranged to transmit the si-Windowlength parameter and the single system information (Sl) message to the at least one wireless communication unit in a variable length transmission time window (Sl window) a number of times, wherein the number of transmissions is based on the si-Windowlength parameter; wherein at least one of: a start time of a transmission of the single SI message, or a duration of the variable length transmission time window(SI window), is determined based on: (i) the si-Windowlength parameter; (ii) a transmission order; and (iii) on the availability for downlink transmissions.