Backscatter Uplink Triggering for Ambient-Powered Wireless Links
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication technologies face challenges in efficiently communicating with low-power or no-power devices, particularly in scenarios involving backscattering-type stations, due to issues with channel contention and power management, which affect the reliability and efficiency of uplink and downlink transmissions.
Innovation Solution
The proposed method includes transmitting a downlink physical layer protocol data unit (PPDU) with a trigger indication to initiate an uplink transmission from a backscattering-type station, utilizing a backscatter-modulating waveform field for power provision, and employing a CTS-to-Self mechanism for link protection, thereby enabling efficient communication with backscattering-type stations and backscattering sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing wireless communication technologies are used for backscattering-type stations, then communication can be established, but channel contention and power management issues reduce reliability and efficiency
Solution Approach 1:
The access point performs preliminary actions by sending a trigger indication in the DL PPDU before the uplink transmission occurs. This trigger indication prepares the backscattering-type station in advance, allowing it to synchronize its backscattering response with the allocated uplink time slot, thereby avoiding channel contention and improving both reliability and efficiency.
Solution Approach 2:
The system implements feedback mechanisms where the access point monitors the uplink transmissions from backscattering-type stations and adjusts subsequent trigger indications accordingly. This feedback loop enables dynamic power management and channel allocation, resolving the contradiction between reliability and efficiency by adapting to actual communication conditions.
2Productivity
If trigger-based uplink transmission is implemented for backscattering-type stations, then channel contention is reduced, but power management complexity increases
Solution Approach 1:
The backscattering-type station performs self-service by autonomously generating its uplink transmission signal through backscattering in response to the trigger indication. The station uses its own received downlink signal as the basis for its uplink transmission, eliminating the need for complex power management circuits while maintaining high communication efficiency.
Solution Approach 2:
The system changes key parameters of the downlink PPDU (such as power levels, timing, and modulation characteristics) to optimize the backscattering response. By carefully controlling these parameters in the downlink, the access point simplifies the power management requirements at the station side while achieving efficient uplink communication.
3Reliability
If DL PPDU with trigger indication is transmitted to initiate uplink transmission, then uplink transmission reliability is improved, but downlink power consumption increases
Solution Approach 1:
Instead of continuous downlink transmissions, the access point uses periodic trigger indications within the DL PPDU structure. These periodic triggers are strategically placed to initiate uplink transmissions only when necessary, reducing overall downlink power consumption while maintaining uplink transmission reliability through scheduled opportunities.
Solution Approach 2:
The access point applies partial action by transmitting only the essential trigger indication components within the DL PPDU rather than full bidirectional communication continuously. This partial transmission approach provides just enough information to initiate reliable uplink transmission while minimizing downlink power consumption.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances communication efficiency by reducing channel contention and power management issues, allowing reliable uplink and downlink transmissions with low-power or no-power devices, including backscattering-type stations and sources, through trigger-based mechanisms and optimized PPDU formats.
Implementation Method 1
a type-3 AMP non-AP STA may be a backscattering-type AMP non-AP STA capable of generating an UL signal by modulating a received DL waveform
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A wireless communication method includes: transmitting, by a device (100, 200), a downlink (DL) physical layer protocol data unit (PPDU) (712) to an ambient power (AMP) non-access point (AP) station (STA) (100, 200), wherein the DL PPDU includes a trigger indication for triggering the AMP non-AP STA to perform an uplink (UL) transmission; and receiving, by the device, a backscattering UL transmission from the AMP non-AP STA in response to the trigger frame comprised in the DL PPDU.