Multi-Level Broadcast and Unicast for sUAVs via Superposition Coding
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Solution Overview
Problem
Current wireless communication technologies for small unmanned aerial vehicles (sUAVs) face challenges in efficiently delivering safety and cooperative awareness messages, such as ADS-B, due to limitations in scalability and communication range, particularly in LTE V2X systems, which require improved spectral efficiency and resource management for beyond line-of-sight operations.
Innovation Solution
The implementation of multi-level transmission using superposition coding, where a common set of resources is utilized to transmit multiple messages, with different groups of sUAVs decoding specific messages using unique Group Radio Network Temporary Identifiers (GRNTIs), enabling concurrent broadcasting of safety and awareness messages to various geographical areas or subsets of vehicles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional wireless communication technologies are used for sUAVs, then communication simplicity is maintained, but spectral efficiency and communication range are insufficient
Solution Approach 1:
The transmission message is segmented into multiple levels (first level message and second level message), where the first level contains broadcast information and the second level contains unicast information. This segmentation allows different subsets of WTRUs to decode different levels based on their GRNTI, improving spectral efficiency by enabling simultaneous broadcast and unicast transmissions over the same resources without requiring separate communication channels.
Solution Approach 2:
The patent implements a nested structure where the second level message is embedded within the first level message transmission. WTRUs first decode the first level message using their GRNTI, then subset WTRUs that received the second GRNTI proceed to decode the nested second level message. This nesting approach allows hierarchical information delivery without increasing overall transmission resources, thereby improving spectral efficiency while maintaining manageable system complexity.
2Reliability
If multiple messages are transmitted to different subsets of sUAVs using separate resources, then message delivery reliability is improved, but resource utilization and spectral efficiency deteriorate
Solution Approach 1:
The patent merges broadcast and unicast transmissions by transmitting both first level and second level messages simultaneously over the same time-frequency resources. Different subsets of WTRUs decode different levels based on their assigned GRNTI values. This merging approach ensures reliable message delivery to all intended recipients while maximizing spectral efficiency by eliminating the need for separate dedicated resources for broadcast and unicast transmissions.
Solution Approach 2:
The patent applies local quality by assigning different decoding capabilities and GRNTI configurations to different subsets of WTRUs. Subset WTRUs with the second GRNTI can decode both first and second level messages, while other WTRUs decode only the first level message. This localized differentiation ensures that each WTRU receives the appropriate level of information reliability needed for its specific application while maintaining overall spectral efficiency.
3Area of stationary object
If broadcast transmissions are sent to all WTRUs, then coverage area is expanded, but message targeting precision for specific subsets deteriorates
Solution Approach 1:
The patent implements dynamic message targeting by using GRNTI-based decoding mechanisms. All WTRUs in the coverage area receive the transmission, but the system dynamically determines which WTRUs can decode which messages based on their GRNTI assignments. The network can flexibly adjust which WTRUs receive the second GRNTI and thus access the second level message, enabling precise targeting of specific subsets while maintaining broad coverage through the first level broadcast message.
Solution Approach 2:
The patent segments the message content into first level and second level messages, where the first level provides broad coverage information accessible to all WTRUs, and the second level provides targeted information for specific subsets. This segmentation allows the system to simultaneously achieve wide coverage area through the first level broadcast while maintaining high targeting precision for the second level unicast messages intended for specific GRNTI-holding WTRUs.
Data Source
AI summary
Systems, methods, and instrumentalities are disclosed for processing a multi-level transmission sent on a common set of resources using superposition coding, comprising determining a first group radio network temporary identifier (GRNTI), wherein the GRNTI is associated with a broadcast transmission to a plurality of wireless transmit/receive units (WTRUs), determining a second GRNTI, wherein the second GRNTI is associated with a transmission to a subset of the plurality of WTRUs that received the first GRNTI, receiving the multi-level transmission, wherein the multi-level transmission comprises a first level message and a second level message, decoding the first level message from the multi-level transmission using the first GRNTI and preconfigured control information, and decoding the second level message from the multi-level transmission using the second GRNTI.