NR-U Channel Occupancy Request Signal via PDCCH Scheduling
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Solution Overview
Problem
There is no solution in existing technologies for transmitting and receiving channel occupancy request signals in the context of new radio access technology based on unlicensed spectrum (NR-U), and specifically, there is no technical solution for designing these signals with consideration for power consumption.
Innovation Solution
A method and apparatus for transmitting and receiving a channel occupancy request signal, where a base station determines the request signal after performing Listen-Before-Talk (LBT) in a direction corresponding to at least one beam, and schedules the transmission of this signal on a Physical Downlink Control Channel (PDCCH). The signal is scrambled with a Radio Network Temporary Identifier (RNTI) associated with a Tracking Area Identity (TA ID) or Wake Up Signal area Identity (WUS area ID), and a UE specific or cell specific sequence is transmitted before the signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If channel occupancy request signal transmission is implemented in NR-U systems, then channel access control capability is improved, but power consumption increases
Solution Approach 1:
The patent extracts the essential function of channel occupancy request signal transmission by utilizing existing PDCCH resources and UE-specific reference signals. Instead of designing a complete new signaling system, the invention extracts and repurposes existing components (PDCCH for signal transmission, UE-specific reference signals for power management) to achieve the required channel access control capability while minimizing additional power consumption.
Solution Approach 2:
The patent applies multi-functionality by making the PDCCH serve dual purposes: its original function for downlink control information transmission and the new function of carrying channel occupancy request signals. Similarly, UE-specific reference signals are used for both channel estimation and power management functions, reducing the need for separate dedicated signaling resources and thereby lowering overall power consumption.
2Productivity
If direction-based LBT is implemented, then transmission opportunities are improved, but system complexity increases
Solution Approach 1:
The patent merges the direction-based LBT mechanism with the existing PDCCH scheduling framework. The LBT procedure is combined with the channel occupancy request signal transmission process, where the base station performs LBT in beam directions and schedules successful transmissions through PDCCH. This integration allows the system to leverage existing scheduling complexity to manage the additional directional LBT requirements, avoiding the need for separate complex control mechanisms.
3Measurement precision
If UE-specific sequence transmission is added before PDCCH, then signal detection accuracy is improved, but transmission time increases
Solution Approach 1:
The patent applies preliminary action by transmitting the UE-specific sequence before the PDCCH carrying the channel occupancy request signal. This sequence serves as a preamble that prepares the UE receiver for accurate signal detection and decoding. The preliminary transmission of the sequence enables the UE to synchronize and identify the upcoming PDCCH more reliably, improving detection accuracy while the time overhead is minimized by using efficient sequence designs and leveraging existing time resources in the transmission frame structure.
Data Source
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AI summary
Disclosed is a method, device, apparatus for transmitting and receiving a request signal, comprising: a base station determines a channel occupancy request signal to be transmitted, the channel occupancy request signal being a request signal for requesting channel occupancy to a terminal after the base station executes a listen-before-talk operation on the direction corresponding to at least one beam; the base station schedules transmission of the channel occupancy request signal on a downlink control channel; the terminal detects the downlink control channel that schedules the transmission of the channel occupancy request signal; and the terminal receives the channel occupancy request signal according to a detection result. The use of the present invention overcomes a defect of the prior art that has no design for the channel occupancy request signal, and implements transmission of an eNB channel occupancy request signal. Furthermore, the solution further provides a solution that can achieve the lowest power consumption.