Flexible Control Information Transmission for LTE Latency Reduction
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Solution Overview
Problem
The existing Long Term Evolution (LTE) system experiences significant end-to-end latency due to the long time interval between control information transmissions, which is caused by the fixed use of OFDM symbols for control information and the subsequent ACK feedback process, leading to delayed retransmissions and next control information transmissions.
Innovation Solution
A method that involves extracting radio resources from a preset resource block set to send control information in a flexible manner, allowing for shorter time intervals between control information transmissions by distributing radio resources evenly in the frequency domain, thereby reducing latency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If control information is transmitted using fixed OFDM symbols in each subframe, then the transmission structure is simple and stable, but the time interval between control information transmissions becomes long, increasing end-to-end latency
Solution Approach 1:
The patent applies dynamics by transitioning from fixed OFDM symbol positions for control information to flexible time-domain resource allocation. Control information can be transmitted in any available time resource within a subframe, allowing the system to adapt transmission timing dynamically based on traffic conditions and latency requirements, thereby reducing end-to-end latency while maintaining manageable complexity through standardized procedures.
Solution Approach 2:
The patent changes the parameter of time resource allocation from fixed to flexible. By allowing control information to be transmitted in variable time positions within subframes rather than at fixed OFDM symbol locations, the system can optimize transmission timing to reduce latency. This parameter change enables more frequent and timely control information transmissions without fundamentally altering the overall transmission structure.
2Speed
If control information transmission requires one complete subframe, then the transmission is reliable and structured, but the transmission speed and responsiveness are reduced due to the long subframe duration
Solution Approach 1:
The patent segments the control information transmission from the complete subframe structure. Instead of requiring one full subframe for control information transmission, the control information can be transmitted in dedicated time resources within the subframe, separating control plane transmissions from data transmissions. This segmentation enables faster control information delivery while maintaining reliability through proper resource allocation and acknowledgment mechanisms.
Solution Approach 2:
The patent implements preliminary action by allocating specific time resources for control information transmission within subframes in advance. This allows the base station to transmit control information immediately when needed rather than waiting for subframe boundaries, reducing transmission delay while maintaining structured and reliable communication through pre-defined resource allocation rules.
3Loss of time
If the base station waits for ACK feedback in subsequent subframes before determining retransmission, then the feedback process is complete and accurate, but the retransmission delay increases significantly
Solution Approach 1:
The patent applies preliminary action by enabling control information transmission in advance within the same subframe structure, allowing the base station to send control information and receive ACK feedback more quickly. This reduces the waiting time for ACK feedback from multiple subframes to within the same or adjacent subframe, significantly reducing retransmission delay while maintaining accurate feedback processing through standardized procedures.
Solution Approach 2:
The patent ensures continuity of useful action by allowing control information transmission to occur more frequently and continuously rather than being constrained by subframe boundaries. This enables the base station to maintain continuous communication flow with the terminal, reducing idle waiting time for ACK feedback and enabling faster retransmission decisions while maintaining processing accuracy through continuous monitoring.
Data Source
AI summary
This application provides a control information transmission method, a base station, and a terminal. The method includes: extracting a radio resource from a preset resource block set, and sending control information in a first time period by using the radio resource. The base station includes a processor and a transmitter. The processor is configured to extract a radio resource from a preset resource block set, and the transmitter is configured to send control information in a first time period by using the radio resource. According to the control information transmission method provided in this application, the base station can send the control information in any time period, and the terminal can receive the control information in any time period, thereby shortening a time interval between two control information transmissions.