Dynamic PRACH to AICH Mapping for E-DCH Resource Allocation
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Solution Overview
Problem
Current AICH mechanisms cannot dynamically allocate E-DCH resources due to a one-to-one mapping between PRACH preambles and E-DCH resources, leading to high collision probability and inefficient resource assignment.
Innovation Solution
Implementing a dynamic mapping of PRACH signature sequences to multiple AICH signature sequences, allowing each PRACH signature to be associated with a set of E-DCH resources, enabling the Node B to allocate resources efficiently and reducing collision probability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a one-to-one mapping between PRACH preambles and E-DCH resources is used, then the AICH mechanism is simple to implement, but the resource allocation efficiency deteriorates and collision probability increases
Solution Approach 1:
The patent implements dynamic mapping between PRACH preambles and E-DCH resources, where the mapping relationship can be flexibly adjusted based on system conditions. The AICH signature sequences are dynamically associated with multiple E-DCH resource sets, allowing the system to adapt resource allocation to varying traffic demands and user conditions, thereby improving allocation efficiency while managing complexity through structured dynamic behavior.
Solution Approach 2:
The patent introduces an additional dimension to the mapping relationship by allowing one PRACH preamble to map to multiple AICH signature sequences, and each AICH signature to represent multiple E-DCH resource sets. This multi-dimensional mapping structure transforms the traditional one-to-one relationship into a many-to-many relationship, significantly increasing resource allocation flexibility and reducing collisions.
2Ease of operation
If a one-to-one mapping between PRACH preambles and E-DCH resources is used, then the resource assignment process is straightforward, but the collision probability increases
Solution Approach 1:
The dynamic mapping mechanism allows the system to adjust the association between PRACH preambles and E-DCH resources based on current system state, user distribution, and resource availability. This dynamic adaptation reduces the likelihood of multiple users selecting the same resource, thereby lowering collision probability while maintaining operational simplicity through standardized procedures.
Solution Approach 2:
The patent segments the E-DCH resources into multiple resource sets, each associated with different AICH signature sequences. This segmentation allows the system to distribute users across different resource sets, reducing the probability of collisions. The segmented structure also enables more granular control over resource allocation while keeping the overall process manageable through systematic assignment rules.
3Speed
If early resource allocation is implemented, then the resource allocation speed improves, but the system complexity increases
Solution Approach 1:
The patent implements preliminary resource allocation by establishing the mapping relationships between PRACH preambles, AICH signatures, and E-DCH resource sets in advance. The Node B prepares multiple AICH signature sequences and their associated resource sets before actual resource allocation occurs. This preliminary setup enables rapid resource assignment during actual allocation events, achieving high speed while managing complexity through pre-computed structured relationships.
Data Source
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AI summary
Apparatus comprising a transmitter arranged to transmit an indicating acquisition indication channel signature wherein said indicating signature is used to indicate an enhanced dedicated channel resource to be used by a user equipment.