DRX Synchronization in Unlicensed Bands
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Solution Overview
Problem
In wireless communication systems using unlicensed bands, interference from coexisting communication protocols hampers quality of service and mobility due to contention-based channel access, leading to unreliable downlink transmission and reception.
Innovation Solution
A method for discontinuous reception (DRX) in unlicensed bands, where a wireless device attempts to acquire downlink synchronization during a synchronization period after transitioning from a sleep state to an active state, and if synchronization is not achieved, it receives downlink data assuming a modulation order of the data scheduled is less than or equal to a specific value, thereby reducing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a wireless device attempts to acquire downlink synchronization during a synchronization period after transitioning from sleep state to active state, then the reliability of downlink reception is improved, but the device complexity increases due to additional synchronization procedures
Solution Approach 1:
The wireless device performs downlink synchronization acquisition during a designated synchronization period immediately after transitioning from sleep state to active state. This preliminary action ensures that synchronization is established before regular data reception begins, improving reliability without requiring continuous synchronization procedures throughout operation.
Solution Approach 2:
The synchronization procedure is performed periodically at specific DRX cycle boundaries rather than continuously. By confining synchronization attempts to specific synchronization periods within the DRX framework, the system maintains reliable downlink reception while avoiding the complexity of continuous synchronization monitoring.
2Object-affected harmful factors
If the wireless device receives downlink data assuming a modulation order of less than or equal to a specific value when synchronization is not acquired, then the interference resistance is improved, but the data transmission speed decreases
Solution Approach 1:
The wireless device changes the modulation order parameter to a more robust configuration (less than or equal to a specific value) when downlink synchronization cannot be acquired. This parameter adaptation reduces sensitivity to interference and channel conditions, allowing reliable data reception at the cost of lower transmission speed.
Solution Approach 2:
The modulation order is dynamically adjusted based on synchronization status. When synchronization is successfully acquired, higher modulation orders can be used for faster transmission. When synchronization fails, the system dynamically switches to more robust lower modulation orders to maintain connectivity and resist interference.
3Use of energy by moving object
If the wireless device operates in discontinuous reception mode in unlicensed band, then the energy consumption is reduced, but the quality of service deteriorates due to contention-based channel access
Solution Approach 1:
The wireless device operates in discontinuous reception mode, periodically switching between sleep and active states according to DRX cycles. This periodic operation significantly reduces energy consumption compared to continuous reception, while maintaining quality of service through proper synchronization and modulation order selection during active periods.
Solution Approach 2:
Despite the discontinuous nature of reception, the system maintains continuous useful action by ensuring that synchronization is acquired during each active period and by using appropriate modulation orders that guarantee reliable data reception. This continuity of successful data transmission maintains quality of service while benefiting from energy savings during sleep periods.
Data Source
AI summary
Provided are a method for discontinuous reception (DRX) in an unlicensed band, and a device using the same. The device is converted from a sleep state to an active state, and attempts downlink synchronization during a synchronization period. If the device does not obtain the downlink synchronization during the synchronization period, downlink data is received in the unlicensed band on the assumption that the modulation order of the downlink data scheduled in the active state is not greater than a specific value.