BDMA Random Access via Beam Sector Location Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In beam division multiple access (BDMA) systems, particularly in massive MIMO technology, the large number of antennas required poses spatial challenges, and existing random access methods are inefficient, leading to redundancy and a high probability of collision, especially for terminals located at the boundary of beam sectors.
Innovation Solution
A random access method that utilizes pattern/polarized antennas to determine the location of terminals within beam sectors by analyzing reference signal strength, allowing terminals to transmit specific preambles based on their location and preferred antenna arrays, enabling the access point to efficiently allocate uplink resources and reduce collision probability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a large number of antennas are used in massive MIMO technology, then system capacity and performance are improved, but spatial requirements and device complexity increase
Solution Approach 1:
The patent segments the large antenna array into multiple sub-arrays, where each sub-array is controlled by a separate beamforming network. This allows the system to achieve massive MIMO capacity while reducing the complexity of any single control unit by dividing the overall antenna control into manageable segments.
Solution Approach 2:
The patent introduces polarization dimension to the antenna system, using polarized antennas that can transmit and receive signals with different polarization states. This adds an additional degree of freedom to the system, enabling increased capacity without proportionally increasing the physical antenna count in each plane.
2Ease of operation
If conventional random access methods are used in BDMA systems, then implementation is simple, but collision probability increases and access efficiency deteriorates
Solution Approach 1:
The patent implements preliminary beam training and sector identification before the actual random access procedure. Terminals first identify their location relative to beam sectors and select appropriate preambles based on this information, which preliminary establishes the correct access path and reduces the probability of collision during the main access process.
Solution Approach 2:
The patent assigns different preamble sequences to different beam sectors and terminal locations (center vs. boundary areas). This local differentiation ensures that terminals in different spatial locations use distinct preambles, reducing collision probability while maintaining the simplicity of the overall random access framework.
3Ease of operation
If terminals at beam sector boundaries use the same random access method as center terminals, then processing is uniform, but redundancy increases and access efficiency decreases
Solution Approach 1:
The patent applies different random access procedures for terminals in center areas versus those in boundary areas of beam sectors. Center terminals use one set of preamble sequences while boundary terminals use another set, which eliminates redundant access attempts and improves overall access efficiency while maintaining uniform processing within each category.
Solution Approach 2:
The patent segments the terminal population into different groups based on their location within beam sectors (center vs. boundary). This segmentation allows the system to apply optimized access methods for each group, reducing redundancy and improving efficiency compared to a uniform approach.
4Area of stationary object
If pattern/polarized antennas are used, then antenna spatial efficiency is improved, but signal characterization and selection complexity increases
Solution Approach 1:
The patent enables terminals to autonomously measure and identify the strength of reference signals from different antenna arrays and beam sectors. The terminal itself performs the characterization work by measuring signal strengths and selecting the appropriate preamble based on its findings, which simplifies the overall system complexity while maintaining high spatial efficiency.
Solution Approach 2:
The patent implements a feedback mechanism where terminals measure reference signal strengths from pattern/polarized antenna arrays and use this information to select appropriate preambles. This feedback loop allows the system to adapt to the actual signal conditions without requiring complex centralized control, balancing spatial efficiency with manageable complexity.
Data Source
AI summary
A random access method in a beam division multiple access (BDMA) system including: receiving, by a terminal, a reference signal of at least one beam sector transmitted from an access point (AP) device; estimating, by the terminal, whether the terminal is in a center area of the beam sector provided by the AP device or in the boundary area of the beam sector by using the strength of the reference signal; transmitting, by the terminal, a different preamble to the AP device in accordance with location information of whether the terminal is located in the center area or in the boundary area; and determining, by the AP device, a target beam sector for transmitting information about uplink resources to be used by the terminal, among a plurality of beam sectors on the basis of the received preamble.