Uplink Control Channel Frequency Resource Mapping in Unlicensed Carriers
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Solution Overview
Problem
Existing LTE systems fail to comply with regulations for transmitting uplink control channels in unlicensed carriers, particularly due to limitations in occupied channel bandwidth and power spectral density, leading to restricted transmission power and bandwidth utilization.
Innovation Solution
A user terminal is designed to transmit uplink control channels across multiple discretely distributed frequency resources at the same timing, utilizing techniques such as frequency-domain repetition and interlaced resource mapping to comply with bandwidth regulations and improve multiplexing capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If uplink control channel is transmitted in unlicensed carrier using existing LTE method, then transmission can be performed, but it fails to comply with regulations regarding occupied channel bandwidth and power spectral density
Solution Approach 1:
The uplink control channel transmission is segmented into multiple discrete frequency resources distributed across the unlicensed carrier bandwidth. Instead of concentrating power in a single continuous bandwidth, the transmission is divided into separate frequency blocks, each complying with individual power spectral density limits while collectively achieving the required occupied channel bandwidth for reliable communication.
2Reliability
If transmission power is increased to improve signal quality, then reception reliability improves, but power spectral density exceeds regulatory limits
Solution Approach 1:
Total transmission power is segmented and distributed across multiple discrete frequency resources. This allows the system to achieve sufficient total power for reliable reception while keeping the power spectral density at each frequency resource within regulatory limits. The segmentation enables compliance with both power and bandwidth regulations simultaneously.
Solution Approach 2:
The system transitions from a single-dimension power increase approach to a multi-dimensional solution by distributing power across multiple frequency dimensions. Instead of increasing power density in one location, the power is spread across multiple frequency resources, achieving the same reception reliability through spatial (frequency-domain) distribution rather than concentration.
3Reliability
If occupied channel bandwidth is expanded to meet regulations, then regulation compliance improves, but available frequency resources for other purposes are reduced
Solution Approach 1:
The occupied channel bandwidth is segmented into multiple discrete frequency resources rather than using a single continuous block. This segmentation allows the system to meet the minimum occupied bandwidth requirements while leaving gaps between the discrete resources that can be utilized for other purposes, thereby optimizing the overall spectral efficiency and preserving frequency resources.
Data Source
AI summary
The present invention is designed so that uplink control channels can be transmitted adequately even in carriers in which listening is required prior to transmission. According to one aspect of the present invention, a user terminal has a transmission section that transmits an uplink control signal in an uplink control channel in a given carrier, and a control section that exerts control to map the uplink control channel to a plurality of frequency resources which are discretely distributed in a frequency direction, at a same timing.