Multi-Antenna CCA Beam Area Control for Unlicensed Band Interference
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Solution Overview
Problem
In 3GPP mobile communication systems, the explosive increase in data traffic necessitates the use of unlicensed bands for wireless signal transmission and reception, requiring minimization of interference with other communication systems and resolving ambiguity in energy sensing with multi-antennas during Clear Channel Assessment (CCA).
Innovation Solution
The method involves controlling the beam area for CCA and wireless signal transmission in unlicensed bands using directional or omni-directional antennas, maintaining the difference between CCA and interference ranges, and employing Tx beam sweeping or Tx multi-beams to avoid increasing interference, while determining the appropriate energy sensing indicator for multi-antenna systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If directional antennas are used for wireless signal transmission in unlicensed bands, then transmission efficiency and signal focus are improved, but interference range and CCA ambiguity increase
Solution Approach 1:
The patent applies local quality by configuring different beam areas for CCA and data transmission separately. The CCA beam area is set to cover a specific spatial region for channel sensing, while the data transmission beam area can be directed differently. This allows the system to maintain focused directional transmission for efficiency while controlling the sensing range to prevent excessive interference with other systems in the unlicensed band.
Solution Approach 2:
The patent segments the beam area configuration into distinct functional regions: a CCA beam area for channel assessment and a data transmission beam area for actual signal transmission. This segmentation allows independent optimization of each function - the CCA area can be configured to sense only in relevant directions while data beams can be steered to target specific users, resolving the contradiction between focused transmission and interference control.
2Productivity
If multi-antenna systems perform CCA, then transmission capacity is improved, but ambiguity in energy sensing indicator selection increases
Solution Approach 1:
The patent segments the multi-antenna system into distinct functional groups: some antennas are designated for CCA operations while others are designated for data transmission. This segmentation resolves the ambiguity by clearly assigning specific antennas to specific functions, allowing the system to leverage multi-antenna capacity without confusion about which antenna's energy indicator to use for CCA decisions.
Solution Approach 2:
The patent applies local quality by assigning different roles to different antennas based on their spatial characteristics and beamforming capabilities. Antennas oriented toward the data transmission direction are used for data transmission, while antennas covering the CCA beam area are used for energy sensing. This functional differentiation eliminates the selection ambiguity while maintaining high transmission capacity through the multi-antenna system.
Data Source
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AI summary
An embodiment of the present invention provides a method for a wireless communication apparatus including a plurality of antennas to transmit and receive a wireless signal in an unlicensed band in a wireless communication system, the method including: performing CCA(Clear Channel Assessment) using the plurality of antennas for a predetermined time duration in the unlicensed band; and if the unlicensed band is determined as an idle state where the unlicensed band is unoccupied by other communication apparatuses, transmitting a wireless signal through the unlicensed band, wherein the performing of CCA may include: obtaining one reference value using energy sensing indicators (ESIs) measured through the plurality of antennas; and determining whether the unlicensed band is idle by comparing the reference value with a CCA threshold.