Two-Level DCI Structure for Variable TTI Detection
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Solution Overview
Problem
Current wireless communication systems face challenges in efficiently detecting control channels with varying transmission time intervals (TTIs), leading to increased packet data latency and reduced system performance, particularly in LTE networks where control channel resources are not optimized for short TTI lengths.
Innovation Solution
The method involves a computer-implemented approach that facilitates the detection of control channels with different TTIs by using a two-level DCI (Downlink Control Information) structure, where slow DCI carries information common to multiple TTIs and fast DCI carries information specific to each TTI, reducing overhead and improving resource allocation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If control channels use fixed transmission time intervals (TTIs), then system stability is maintained, but latency increases and system performance deteriorates when shorter TTIs are needed
Solution Approach 1:
The patent implements dynamic TTI configuration where control channels can adapt their transmission time intervals based on traffic conditions and service requirements. The system transitions from fixed TTI to variable TTI by introducing multiple TTI lengths (e.g., 1ms, 0.5ms, 0.25ms) that can be selected and configured dynamically, allowing the control channel structure to be flexible rather than static.
Solution Approach 2:
The patent changes the TTI parameter from a fixed value to a variable parameter that can take multiple values. By introducing a TTI indication field in DCI formats and configuring multiple TTI lengths through higher layer signaling, the system enables parameter changes that allow control channels to operate with different TTI lengths depending on service requirements, thereby reducing latency for time-sensitive traffic.
2Productivity
If control channel resources are increased to support multiple TTI lengths, then system performance improves, but control overhead increases
Solution Approach 1:
The patent segments control information into different DCI formats (e.g., DCI format 0/1A for uplink/downlink, DCI format 5 for uplink, DCI format 6 for downlink) with specific TTI indication fields. Each DCI format is optimized for specific purposes and includes only necessary information elements, reducing redundant control signaling. The segmentation of control information allows efficient resource allocation without excessive overhead.
Solution Approach 2:
The patent creates universal DCI formats that can handle multiple TTI lengths through the inclusion of TTI indication fields. These DCI formats serve multiple functions by accommodating different TTI configurations (1ms, 0.5ms, 0.25ms) within the same control structure, eliminating the need for separate control channels for each TTI length and thereby reducing overall control overhead.
3Difficulty of detecting and measuring
If existing DCI formats are used without modification, then implementation complexity is low, but detection of control channels with different TTIs fails
Solution Approach 1:
The patent incorporates TTI indication fields预先 (in advance) in the DCI format structures before actual control channel transmission. The TTI length is indicated in the DCI itself, allowing the UE to prepare for the appropriate TTI configuration before receiving the actual control information. This preliminary indication simplifies the detection process by providing advance notice of the TTI length that will be used.
Solution Approach 2:
The patent introduces TTI indication fields as intermediary elements within the DCI formats that bridge the gap between the control channel and the data channel. These indication fields act as mediators that convey TTI length information from the network to the UE, enabling the UE to correctly interpret and process control channels with different TTI lengths without requiring complex detection algorithms.
Data Source
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AI summary
Facilitation detection of control channels with different transmission time intervals (TTIs) in wireless communications systems is described herein. Preferably, a computer-implemented method comprises: monitoring, by a mobile device (116) comprising a processor (308), a first control channel in the beginning of a first TTI; and receiving, by the mobile device (116), a first downlink control information (DCI) on the first control channel in the first TTI, wherein information of the first DCI indicates a pattern of a second TTI associated with a second control channel, and wherein the second control channel occurs later than the first control channel and the second TTI is shorter than the first TTI. The computer-implemented method can also comprise determining, by the mobile device (116), whether to monitor the second control channel of the second TTI based on the information of the first DCI.