Vehicle Antenna Array Spacing to Prevent Reception Null Points
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Solution Overview
Problem
Existing vehicle-to-vehicle communication systems lack an optimal antenna array configuration method, leading to periodic fluctuations in reception levels due to interference from road and side reflectors, which can result in null points and decreased communication quality, especially in environments like tunnels where reflector distances vary.
Innovation Solution
The proposed system configures an antenna array with antennas shifted by odd multiples of half periods of maximum and minimum fluctuation periods, ensuring optimal spacing to avoid null points and improve reception quality, even in complex environments like tunnels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If antennas are arranged with conventional spacing (half wavelength or more), then spatial diversity is achieved for non-line-of-sight communication, but reception levels fluctuate periodically and null points occur in line-of-sight communication environments with reflectors
Solution Approach 1:
The patent changes the antenna spacing parameter from conventional half-wavelength spacing to odd multiples of half fluctuation periods (Lmax/2, Lmin/2). This parameter transformation resolves the contradiction by adapting the spacing to the specific propagation environment characteristics rather than using fixed conventional values, thereby eliminating periodic fluctuations and null points while maintaining spatial diversity.
Solution Approach 2:
The patent introduces dynamic adaptation by calculating fluctuation periods based on actual reflector distances and adjusting antenna spacing accordingly. Instead of using fixed spacing, the system dynamically determines optimal spacing based on environmental parameters, preventing null points while maintaining communication reliability.
2Reliability
If antenna spacing is increased to 10 wavelengths or more for base station spatial diversity, then diversity effect is improved, but device complexity and space requirements increase
Solution Approach 1:
The patent transforms the antenna spacing parameter from fixed wavelength-based values to fluctuation period-based values (odd multiples of Lmax/2 and Lmin/2). This change achieves effective spatial diversity without requiring excessive spacing, thereby reducing device complexity and space requirements while maintaining or improving diversity effects.
3Adaptability or versatility
If antennas are arranged to cover various environments, then adaptability is improved, but reception quality deteriorates due to null points in specific environments like tunnels
Solution Approach 1:
The patent implements dynamic environment adaptation by calculating fluctuation periods based on actual reflector distances in the current environment. The system determines optimal antenna spacing (odd multiples of Lmax/2) specific to each environment, thereby maintaining high reception quality across various conditions including tunnels, open areas, and urban environments without suffering from null points.
Solution Approach 2:
The patent applies local optimization by tailoring antenna spacing to specific environmental characteristics. Instead of using a universal fixed spacing, the system calculates and applies locally optimal spacing based on reflector distances and fluctuation periods specific to each deployment location, ensuring high reception quality in every local environment.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enhances communication quality by stabilizing reception levels and preventing null points, thereby improving the reliability of vehicle-to-vehicle communication, especially in environments with varying reflector distances.
Implementation Method 1
periodic fluctuations in reception levels due to interference from road and side reflectors
Data Source
AI summary
Provided is an antenna apparatus mounted on a movable object, the antenna apparatus including an antenna array including: a plurality of first antennas which are arranged by being shifted by a distance equivalent to an odd multiple of a half period of a maximum fluctuation period of a radio wave having a longest fluctuation period among a plurality of radio waves received from an antenna of a communication partner; and a plurality of second antennas which are respectively arranged by being shifted with respect to the plurality of first antennas by a distance equivalent to an odd multiple of a half period of a minimum fluctuation period of a radio wave having a shortest fluctuation period among the plurality of radio waves.