Antenna Reassignment for LTE Unlicensed Spectrum Interference
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Solution Overview
Problem
Wireless communication networks, particularly LTE/LTE-A networks, face interference and congestion issues due to the increasing demand for mobile broadband access, which existing technologies have not adequately addressed when utilizing unlicensed spectrum.
Innovation Solution
The method involves monitoring for channel reserving signals and reassessing receive antenna usage based on clear channel assessment (CCA) status, allowing for dynamic reassignment of antennas between licensed and unlicensed carriers to optimize communication efficiency and reduce interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple transmission sources operate in unlicensed spectrum simultaneously, then network capacity and broadband access are improved, but interference and congestion increase
Solution Approach 1:
The patent implements dynamic antenna reassignment where the base station monitors CCA status and channel conditions in real-time, then dynamically adjusts which antennas are assigned to which transmission sources. This dynamic adaptation allows the system to optimize network capacity while minimizing interference by reallocating antennas based on current channel conditions rather than using fixed assignments.
Solution Approach 2:
The system changes the parameter of antenna assignment configuration based on CCA status. When CCA indicates clear channel conditions, antennas are assigned to unlicensed carriers for transmission. When CCA detects busy channels or interference, the antenna assignments are modified to avoid conflicting transmissions, thereby maintaining high network capacity while reducing harmful interference.
2Productivity
If antennas are assigned to multiple transmission sources, then communication efficiency is improved, but antenna resource conflicts and interference increase
Solution Approach 1:
The base station implements a feedback mechanism by monitoring CCA status from transmission sources and using this information to make informed antenna reassignment decisions. The CCA feedback indicates whether the channel is clear or busy, allowing the base station to adjust antenna assignments to maintain communication efficiency while preventing interference caused by simultaneous transmissions on contested channels.
Solution Approach 2:
The system performs preliminary CCA checks before assigning antennas to transmission sources. By checking channel availability in advance and proactively reassigning antennas before conflicts occur, the system maintains high communication efficiency while preventing interference from arising in the first place.
3Device complexity
If fixed antenna assignment is used, then system complexity is reduced, but adaptability to changing channel conditions deteriorates
Solution Approach 1:
The base station autonomously monitors CCA status and performs antenna reassignments without requiring complex external control systems. This self-service approach allows the system to adapt to changing channel conditions dynamically while keeping the overall system complexity manageable, as the adaptation logic is embedded in the base station's existing resource management functions.
Data Source
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AI summary
Antenna selection and reassignment in multiple radio access technology (RAT) communication systems with unlicensed spectrum is disclosed. Aspects include a user equipment (UE) monitoring for a channel reserving signal in each frame from multiple transmission sources. If no channel reserving signal is detected, then the UE reassigns one or more of the antennas previously assigned to the transmission sources with no activity detected. Additional aspects include base stations that determine a clear channel assessment (CCA) status for each of unlicensed carrier designated for transmission to a UE. The base station will transmit a receive antenna usage adjustment signal to the UE based on the determined CCA status.