Dual Codebook CSI Reporting on PUSCH for LTE Rel-10
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing PUSCH reporting mechanism in LTE Rel-8/9 is designed for single-codebook and single-user scenarios, failing to accurately distinguish between long-term/wideband CSI and short-term/frequency-selective CSI, making it unsuitable for the dual codebook-based PUSCH reporting mechanism in LTE Rel-10.
Innovation Solution
A method and apparatus for reporting CSI on PUSCH using dual codebooks, where the entire bandwidth is divided into subsets, allowing for the creation and transmission of both long-term/wideband CSI and short-term/frequency-selective CSI, enabling a two-level feedback scheme with new reporting modes that include PMI-1 and PMI-2 for long-term/wideband and short-term/frequency-selective conditions respectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single-codebook-based PUSCH reporting mechanism is used, then the system is simpler to implement, but it cannot accurately distinguish between long-term/wideband CSI and short-term/frequency-selective CSI, making it unsuitable for dual codebook-based reporting in multi-user scenarios
Solution Approach 1:
The patent segments the single-codebook reporting mechanism into two separate codebooks: a first codebook for long-term/wideband CSI and a second codebook for short-term/frequency-selective CSI. This segmentation allows the system to accurately distinguish and report different types of channel state information separately, enabling support for dual codebook-based PUSCH reporting mechanisms while maintaining manageable complexity through structured organization.
2Measurement precision
If the entire bandwidth is reported as a single unit, then the reporting process is simpler, but it loses the ability to provide frequency-selective CSI information needed for optimized resource allocation
Solution Approach 1:
The patent divides the entire system bandwidth into multiple subsets of bands. The UE creates long-term/wideband CSI for the entire bandwidth and short-term/frequency-selective CSI for specified subsets of bands. This segmentation enables precise frequency-selective measurements while maintaining a structured reporting framework that manages complexity through clear division of reporting responsibilities.
Solution Approach 2:
The patent applies different reporting qualities to different bandwidth portions: wideband CSI provides overall channel characteristics for the entire bandwidth, while sub-band CSI provides detailed frequency-selective information for specific subsets. This local quality approach ensures that frequency-selective resources are optimized with precise local measurements without requiring full-bandwidth detailed reporting, balancing precision and complexity.
Data Source
AI summary
A method and apparatus for reporting channel state information (CSI) based on a physical uplink shared channel (PUSCH) are used to realize correct reporting of the CSI based on double code books. The method includes the following steps: a reporting mode configuration signaling for the CSI sent from a network side is received, and said reporting mode configuration signaling for the CSI at least carries a designated reporting mode identifier; a first CSI aiming at the whole bandwidth of a system is established according to a reporting type corresponding to said reporting mode identifier; the whole bandwidth of the system is divided into at least two frequency band subclasses, and a second CSI aiming at a designated frequency band subclass is established according to the reporting type corresponding to said reporting mode identifier; and when a reporting indication signaling sent from the network side is received, said first CSI and said second CSI are transmitted to the network side. Therefore, when a user equipment (UE) reports the CSI, a long-term/wideband CSI and a short-term/frequency selective CSI could be considered comprehensively, then a two-level feedback mechanism based on the PUSCH double code books is realized.