Antenna Subarray Beamforming for Broad Azimuth Coverage
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Solution Overview
Problem
Existing wireless communication systems face challenges in transmitting control channels across a broad azimuth range using antenna arrays, as they require high power transmission to cover the entire cell area, which limits antenna design and efficiency.
Innovation Solution
The method involves forming two subarrays from an antenna array and selecting beamforming weights based on a recursive relation to ensure complementary radiation patterns, allowing for efficient transmission of control channels using a Space Frequency Block Code like the Alamouti Code, ensuring reliable reception across the azimuth range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a single antenna element is used to transmit over a broad angular range, then coverage area is improved, but transmit power requirement increases
Solution Approach 1:
The antenna array is divided into multiple subarrays, each responsible for transmitting signals in specific angular sectors. This segmentation allows the system to achieve broad coverage by coordinating multiple lower-power subarrays rather than relying on a single high-power antenna element.
Solution Approach 2:
Each subarray is configured with specific beamforming weights to optimize its radiation pattern for particular angular ranges. This local optimization allows each subarray to operate at lower power while maintaining effective coverage in its designated sector, collectively achieving broad coverage without requiring any single element to operate at high power.
2Length of moving object
If all antenna elements are used for transmission, then beam narrowness is improved, but angular coverage range decreases
Solution Approach 1:
The antenna array is segmented into multiple subarrays that can independently form beams. Each subarray can be configured to create narrow beams in specific directions, and by coordinating multiple subarrays with different beam directions, the system achieves both beam narrowness and broad angular coverage.
Solution Approach 2:
The system transitions from a single-dimension approach (one beam direction) to a multi-dimensional approach by utilizing multiple subarrays that can form beams in different angular dimensions simultaneously. This allows the system to maintain narrow beamwidths while covering a broad angular range through spatial diversity.
3Measurement precision
If beamforming weights are optimized for narrow beam, then transmission precision is improved, but coverage breadth deteriorates
Solution Approach 1:
The antenna array is divided into multiple subarrays, each optimized to form narrow, precise beams in specific angular sectors. By coordinating multiple such subarrays with complementary radiation patterns, the system achieves both high transmission precision within each sector and broad overall coverage across all sectors.
Solution Approach 2:
The system dynamically adjusts beamforming weights for each subarray to optimize beam characteristics for different angular regions. This parameter optimization allows each subarray to achieve precise transmission in its designated sector while the collective system maintains broad coverage through coordinated parameter changes across all subarrays.
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 approach enables reliable transmission of control channels across a broad azimuth range without the need for a single high-power antenna element, improving coverage and reducing design constraints on base stations.
Implementation Method 1
Beamforming weights are selected for each subarray so that the radiation patterns are complementary over a range of the azimuth of a cell
Implementation Method 2
an array antenna comprising a first set of array elements and a second set of array elements, each array element having an associated beamforming weight
Data Source
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AI summary
Methods, systems, and devices are described for transmitting across a broad azimuth using an antenna array. In one example, a method is described that includes forming two subarrays from an antenna array. Beamforming weights are selected for each subarray to cause the radiation patterns to be complementary over a range of the azimuth of a cell. The beamforming weights may be selected according to a recursive relation based on the number of antenna elements in each subarray. Information may be encoded, scrambled, and mapped to modulation symbols. A Space Frequency Block Code (SFBC) such as an Alamouti Code may then be used to form two signals to be transmitted over the two subarrays.