Modified PUCCH Format 1b for Periodic CQI Reporting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current LTE systems face inefficiencies in uplink physical uplink channel (PUCCH) overhead due to excessive multiple access interference and poor multiplexing capacity, particularly in periodic channel quality indicator (CQI) reporting, which affects spectrum efficiency and resource usage.
Innovation Solution
The method involves selecting a transmission format for periodic CQI reporting based on the size of the CQI report, using either PUCCH format 2 or a modified PUCCH format 1b, which applies block-level spreading and space-time coding between block-wise spread SC-FDMA symbols, allowing for efficient resource utilization and reduced overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If PUCCH format 2 is used for periodic CQI reporting, then the channel quality information can be transmitted, but the uplink overhead increases and multiplexing capacity decreases
Solution Approach 1:
The patent changes the transmission format parameter from PUCCH format 2 to modified PUCCH format 1b, which uses block-level spreading and space-time coding. This parameter change reduces the uplink overhead while maintaining CQI reporting capability, directly resolving the contradiction between information transmission and overhead reduction.
2Loss of information
If PUCCH format 2 is used for periodic CQI reporting, then the CQI data can be transmitted, but the multiplexing capacity becomes poor
Solution Approach 1:
The patent applies parameter change by switching from PUCCH format 2 to modified PUCCH format 1b with block-level spreading. This enables better multiplexing of multiple UEs in the same time-frequency resources, improving multiplexing capacity while maintaining CQI reporting functionality.
3Productivity
If more UEs are multiplexed per physical resource block, then spectrum efficiency improves, but interference between users increases
Solution Approach 1:
The patent converts the harmful multiple access interference into a beneficial signal through block-level spreading and space-time coding. By spreading the CQI signal across multiple resource elements and applying space-time coding, the system can tolerate and even exploit the presence of multiple simultaneous transmissions, enabling higher multiplexing capacity with controlled interference.
4Productivity
If modified PUCCH format 1b is used with block-level spreading, then multiplexing capacity improves and overhead reduces, but backward compatibility must be maintained
Solution Approach 1:
The patent achieves universality by designing a modified PUCCH format 1b that serves multiple functions: it provides improved multiplexing capacity through block-level spreading while maintaining compatibility with existing LTE infrastructure. The format can be used by both legacy and enhanced systems, allowing gradual deployment and maintaining backward compatibility.
Data Source
AI summary
A solution for periodic channel quality indicator reporting in a communications system is disclosed. A user equipment performs the method steps of receiving radio resource configuration signalling from a network apparatus, and checking a channel quality indicator mode of the received radio resource configuration signalling. Based on said checking, the user equipment determines a container for a periodic channel quality indicator report, and based on said determining, selects a physical uplink control channel transmission format for the periodic channel quality indicator report. If the determined container of the periodic channel quality indicator report is a reduced-bit container, a modified physical uplink control channel format 1b is selected as the physical uplink control channel transmission format for the periodic channel quality indicator report.