Random Access Message 3 Repetition for Stable Uplink Transmission
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Solution Overview
Problem
In wireless communication systems like LTE and NR, the transmission success rate of message 3 in the random access procedure is low due to low signal-to-interference-plus-noise ratio in coverage-limited scenarios, leading to increased access delays and potential network access failures.
Innovation Solution
The method involves the terminal device repeatedly transmitting message 3 using the same transmit power and precoding matrix, combined with joint channel estimation and various frequency hopping modes to improve transmission stability and success rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If message 3 is retransmitted to improve transmission success rate, then transmission success rate is improved, but access delay is increased
Solution Approach 1:
The patent applies preliminary action by performing joint channel estimation before message transmission using downlink reference signals. This preliminary channel estimation enables more accurate message 3 transmission, improving success rate and reducing the need for retransmissions, thereby decreasing access delay.
Solution Approach 2:
The patent replaces the conventional separate channel estimation approach with a unified joint channel estimation mechanism that combines downlink and uplink channel estimates. This substitution improves estimation accuracy and transmission reliability without increasing retransmission attempts.
2Reliability
If transmit power is increased to improve message 3 transmission in coverage-limited scenarios, then transmission success rate is improved, but power consumption is increased
Solution Approach 1:
The patent changes the parameter of channel estimation accuracy by implementing joint channel estimation that combines downlink and uplink channel information. This parameter change improves transmission success rate without requiring increased transmit power, as the improved estimation enables more efficient power utilization.
3Reliability
If conventional separate channel estimation is used, then system complexity is low, but transmission accuracy is insufficient leading to low transmission success rate
Solution Approach 1:
The patent merges separate downlink channel estimation and uplink channel estimation into a unified joint channel estimation process. By combining these estimation functions and sharing computational resources, the patent achieves higher transmission accuracy while controlling system complexity through resource sharing and integration.
Data Source
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AI summary
A communication method and apparatus are provided. The method includes: A network device receives a random access request from a terminal device; and the network device sends a random access response to the terminal device, where the random access response includes scheduling information of a message 3, the scheduling information includes first information, and the first information indicates the terminal device to repeatedly transmit the message 3 by using same transmit power and a same precoding matrix. When repeatedly transmitting the message 3, the terminal device uses the same transmit power and the same precoding matrix, so that stability of transmission of the message 3 can be improved, and a transmission success rate of the message 3 can be improved, thereby improving an access success rate of a random access procedure of the terminal device.