D2D Subframe Bitmap Adaptation for Wireless Communication Delay
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Solution Overview
Problem
In Device-to-Device (D2D) communication, existing wireless communication systems face challenges in efficiently determining subframe indicators for data transmission, leading to delays and half-duplex issues due to limitations in Uplink/Downlink (UL/DL) configurations.
Innovation Solution
A method and apparatus for a User Equipment (UE) to determine a bitmap for a subframe pool using a subframe indicator bitmap, where the number of 1s (k) in the bitmap is adjusted based on specific UL/DL configurations, allowing for optimized D2D data transmission by selecting appropriate subframes for data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If a fixed subframe indicator bitmap is used for D2D data transmission, then the system structure is simple, but transmission delay increases and half-duplex problems occur due to UL/DL configuration limitations
Solution Approach 1:
The patent applies dynamics by making the subframe indicator bitmap adaptive rather than fixed. The bitmap is dynamically determined based on the UL/DL configuration and the set of available subframes for D2D communication. This allows the system to adapt to different TDD configurations and avoid half-duplex problems by selecting appropriate subframes for D2D transmission, thereby reducing transmission delay while managing complexity through structured adaptation rules.
2Productivity
If the number of 1s in the subframe indicator bitmap is increased to provide more transmission opportunities, then productivity improves, but the risk of interference and half-duplex conflicts increases
Solution Approach 1:
The patent applies local quality by differentiating the bitmap determination for different UL/DL configurations. Instead of using a uniform approach, the system tailors the subframe indicator bitmap to specific TDD configuration characteristics. This allows optimizing D2D transmission opportunities in each local context (configuration-specific) while avoiding interference with uplink/downlink assignments, thus improving productivity without exacerbating harmful factors.
Solution Approach 2:
The patent changes parameters by adjusting the number of 1s in the subframe indicator bitmap based on the UL/DL configuration and available subframe sets. The parameter k (number of 1s) is selected from a configured set of values, allowing flexible adjustment of transmission opportunities. This parameter adaptation enables the system to optimize D2D transmission rate while avoiding half-duplex conflicts by selecting appropriate k values for different operational conditions.
3Loss of energy
If D2D communication is implemented without eNB intervention to reduce overhead, then network overhead decreases, but resource coordination and interference management become more difficult
Solution Approach 1:
The patent applies self-service by enabling UEs to autonomously determine subframe indicator bitmaps for D2D communication without continuous eNB intervention. The UE uses pre-configured parameters (set of k values, UL/DL configuration) to independently select appropriate subframes for D2D transmission. This reduces network overhead significantly while managing coordination complexity through standardized self-determination rules that ensure consistent resource allocation across the network.
Data Source
AI summary
According to an embodiment of the present invention, a method for transmitting Device-to-Device (D2D) data by a User Equipment (UE) in a wireless communication system, the method comprising: determining a bitmap to be applied to a subframe pool for data transmission from a subframe indicator bitmap; determining a set of subframes to transmit D2D data by using the bitmap to the subframe pool for data transmission; and transmitting D2D data in a subframe included in the determined subframe set, wherein a set of values available as k being the number of 1s in the subframe indicator bitmap are changed according to a Uplink/Downlink (UL/DL) configuration set to which a UL/DL configuration configured for the UE belongs.