LTE-U Channel Access via Switching Duration Signal Reservation
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Solution Overview
Problem
The LTE-U system experiences low channel access capacity due to existing channel access mechanisms, leading to user equipment being blocked by others in the same cell, which degrades performance and wastes radio resources.
Innovation Solution
A method and device that transmit a signal in a switching duration between downlink and uplink sub-frames to occupy channels, using Clear Channel Assessment (CCA) detection to ensure the channel is idle before transmitting, thereby improving channel access capacity and enabling Multiple User-Frequency Division Multiplexing (MU-FDM) and Multiple User-Space Division Multiplexing (MU-SDM) modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the existing channel access mechanism is used in LTE-U system, then the system can operate with centralized control, but the channel access capacity becomes low and user equipment gets blocked
Solution Approach 1:
The patent applies preliminary action by performing Clear Channel Assessment (CCA) detection before channel access. The network device transmits a signal in the switching duration to reserve the channel in advance, and user equipment performs CCA detection before transmitting uplink signals. This preliminary channel assessment and reservation prevents blocking and improves both channel access capacity and reliability by ensuring the channel is available before transmission attempts.
2Adaptability or versatility
If Multiple User-Frequency Division Multiplexing and Multiple User-Space Division Multiplexing modes are supported, then more users can access the channel, but channel blocking increases without proper access control
Solution Approach 1:
The patent implements feedback through the CCA detection mechanism. User equipment detects the channel status by listening to signals from the network device and other users. Based on this feedback information about channel occupancy, users adjust their transmission timing and frequency selection. This feedback loop enables multiple users to coexist in MU-FDM and MU-SDM modes while preventing blocking by ensuring users only transmit when the channel is clear.
Data Source
AI summary
The present invention discloses a data transmission method and device configured to address the problems in LTE-U employing the existing channel access mechanism, in which poor channel access capacity is caused, and congestion between UEs in the same cell is likely to occur if multiple UEs cannot access at the same time. The method comprises: sending, by a communication device, a signal during a GP between a downlink subframe and an uplink subframe to occupy a current channel; and transmitting, by the communication device, data via the current channel. The solution provided in embodiments of the present invention has low implementation complexity, and can address the problem of UL having a poorer opportunity to access than WIFI, thus facilitating the implementation of MU-FDM and MU-SDM to prevent significant degradation of LAA performance and a waste of radio resources.