LTE-A Random Access Preamble Carrier Selection via eNodeB Indicator
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Solution Overview
Problem
In the LTE-A system, user equipment cannot determine a specific uplink component carrier for transmitting a random access preamble, leading to potential failures in the random access procedure and wastage of uplink resources due to concurrent transmission over multiple carriers.
Innovation Solution
The eNodeB transmits an identifier of the uplink component carrier to the user equipment, allowing it to select and transmit the random access preamble over a specific carrier, ensuring compatibility and efficient resource utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If user equipment transmits random access preamble over multiple uplink component carriers concurrently, then the probability of successful reception by eNodeB increases, but uplink resource waste occurs
Solution Approach 1:
The patent changes the parameter of carrier selection from random/multiple to specific/single by introducing carrier indicator information that explicitly identifies which uplink component carrier should be used for random access preamble transmission. This parameter change resolves the contradiction by ensuring reliable transmission on the designated carrier without wasting resources on unnecessary multiple carrier transmissions.
2Ease of operation
If user equipment transmits random access preamble over wrong uplink component carrier, then transmission can proceed, but random access procedure fails
Solution Approach 1:
The patent introduces carrier indicator information as an intermediary that mediates between the user equipment and the uplink component carrier selection. This intermediary provides the necessary guidance to ensure the preamble is transmitted on the correct carrier, maintaining ease of operation while ensuring reliability through proper carrier identification.
3Productivity
If carrier aggregation is implemented to improve peak rates, then system capacity increases, but user equipment cannot determine specific uplink component carrier for random access
Solution Approach 1:
The patent applies preliminary action by providing carrier indicator information in advance through message 0 or system information before the random access procedure begins. This allows user equipment to correctly identify and select the specific uplink component carrier for preamble transmission, maintaining the benefits of carrier aggregation while preventing information loss about carrier identification.
Data Source
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AI summary
A method, a system and a device for sending a random access preamble are provided. The method includes: a base station determines an uplink component carrier to be utilized by a terminal for sending a random access preamble, and sends identification information of the uplink component carrier to the terminal (30); and the terminal selects a component carrier corresponding to the uplink component carrier identification from multiple uplink component carriers which are supported by the terminal, and sends a random access preamble to the base station utilizing the component carrier (31). With the invention, a terminal in a Long Term Evolution Advanced (LTE-A) system can select a component carrier for sending a random access preamble based on indication of a base station.