PRACH Resource Segmentation for LTE-Advanced Random Access
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Solution Overview
Problem
The LTE-Advanced system faces challenges in handling random access procedures, particularly with relay deployment and carrier aggregation, due to difficulties in determining whether a UE should access a base station or a relay, insufficient resources for differentiating access points or component carriers, and unresolved issues with in-band relaying operations affecting communication timing and resource allocation.
Innovation Solution
A method is introduced to configure multiple access points or component carriers with diverse PRACH resources, preamble formats, and sequences, allowing mobile devices to select the best access point or component carrier based on measurement and network indications, and to manage random access procedures by setting different power control parameters, RAR windows, and contention resolution timers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If relay deployment is implemented to extend coverage and improve cell-edge throughput, then coverage and data rate are improved, but the system faces difficulties in determining whether a UE should access a base station or a relay, and interference issues arise from in-band relaying operations
Solution Approach 1:
The patent segments the random access resources by introducing distinct PRACH resources, preamble formats, and sequences for different access points (base stations versus relays). This segmentation enables UEs to clearly identify and select appropriate access points based on configured parameters, resolving the complexity of access determination while maintaining extended coverage benefits
Solution Approach 2:
The patent applies local quality by configuring specific PRACH parameters (resources, formats, sequences) that are locally unique to each access point type. This allows UEs to differentiate between base stations and relays through localized parameter identification, simplifying access decisions without compromising coverage extension
2Power
If carrier aggregation is implemented to extend bandwidth to 100 MHz, then data rate is improved, but insufficient resources exist for differentiating access points or component carriers in random access procedures
Solution Approach 1:
The patent resolves resource insufficiency by introducing additional differentiation dimensions beyond simple resource quantity. By using multiple dimensions including preamble formats, sequence types, and configuration parameters, the system can uniquely identify access points and component carriers even with limited PRACH resources, thereby supporting high data rates through carrier aggregation
3Productivity
If in-band relaying operation is used to improve system efficiency, then system efficiency is improved, but communication timing and resource allocation become unresolved due to interference between eNB-to-relay and relay-to-UE links
Solution Approach 1:
The patent segments communication resources by introducing distinct PRACH configurations and timing parameters for different link types in in-band relaying. This segmentation allows the system to maintain high efficiency by enabling UEs to properly time and allocate resources for communications with relays versus base stations, resolving timing conflicts caused by in-band interference
Data Source
AI summary
A method of handling random access procedure for a network in a wireless communications system is disclosed. The method comprises configuring a plurality of access points or a plurality of component carriers with at least one of a plurality of physical random access channel (PRACH) resources, a plurality of preamble formats, and a plurality of preamble sequences, whereby a mobile device of the wireless communication system uses at least one of the plurality of PRACH resources, the plurality of preamble formats, and the plurality of preamble sequences to access at least one of the plurality of access points or the plurality of component carriers when performing at least a random access procedure.