DMRS-Based Downlink Signal Reception With Dynamic RE Pairing
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Solution Overview
Problem
Current wireless communication systems face limitations in efficiently reporting channel state information, particularly for Narrow Band Internet of Things (IoT) User Equipment, which affects the performance of downlink signal transmission in environments requiring enhanced Full Dimension Multiple Input Multiple Output (eFD-MIMO) schemes.
Innovation Solution
A method and apparatus for aperiodic channel state reporting using a Demodulation Reference Signal (DMRS)-based transmission scheme, allowing rate matching or time-wise Resource Element (RE) pairing for REs not forming frequency-wise pairs in Space Frequency Block Coding (SFBC), optimizing data allocation and transmission in wireless communication systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If DMRS-based OL MIMO scheme is introduced to support eFD-MIMO, then the ease of precoding operation is improved, but the complexity of resource element pairing and rate matching increases
Solution Approach 1:
The patent segments the resource element handling into two distinct approaches: frequency-wise RE pairing for SFBC and time-wise RE pairing for DMRS-based schemes. This segmentation allows the system to apply different pairing strategies to different transmission schemes, simplifying the overall operation while maintaining flexibility. The indication information field in DCI formats further segments the control mechanism, allowing dynamic selection between pairing methods without increasing overall system complexity.
Solution Approach 2:
The patent introduces dynamic switching capability between frequency-wise RE pairing and time-wise RE pairing through indication information transmitted in DCI formats (0, 1, 1A, 1B, 1C, 2, 2A, 2B, 2C, 3, 3A). This dynamic mechanism allows the system to adapt the RE pairing method according to the specific transmission scheme being used, resolving the complexity issue while maintaining ease of operation for different MIMO schemes.
2Reliability
If rate matching is applied to REs not forming frequency-wise pairs for SFBC, then the reliability of data transmission is improved, but the productivity of resource utilization decreases
Solution Approach 1:
The patent changes the fundamental parameter of RE pairing from frequency-wise to time-wise for DMRS-based transmission schemes. This parameter change allows the system to maintain reliability through proper rate matching while improving productivity by utilizing previously unused time-domain REs. The indication information mechanism enables dynamic adjustment of this parameter based on the transmission scheme, optimizing both reliability and resource utilization efficiency.
Solution Approach 2:
The patent transitions from frequency-domain RE pairing (frequency-wise) to time-domain RE pairing (time-wise) for DMRS-based schemes. This dimensional change from frequency to time domain allows the system to utilize resources that would otherwise remain unused, improving productivity while maintaining transmission reliability through appropriate rate matching procedures.
3Productivity
If time-wise RE pairing is implemented for DMRS-based schemes, then the productivity of resource allocation is improved, but the difficulty of detecting and measuring RE pairs increases
Solution Approach 1:
The patent implements feedback mechanisms through indication information transmitted in DCI formats, which provide explicit guidance to the receiver about which RE pairing method is being used. This feedback reduces the difficulty of detecting and measuring RE pairs by eliminating ambiguity, allowing the receiver to correctly interpret the time-wise paired RE structure without increasing detection complexity.
Solution Approach 2:
The indication information acts as an intermediary between the transmitter and receiver, conveying the RE pairing configuration. This intermediary mechanism simplifies the detection and measurement process by providing clear, pre-negotiated rules for identifying time-wise RE pairs, reducing the computational burden and complexity at the receiver side.
4Adaptability or versatility
If indication information is added to DCI formats to signal RE pairing method, then the adaptability of the transmission scheme is improved, but the loss of information due to additional signaling overhead increases
Solution Approach 1:
The patent makes the existing indication information fields in multiple DCI formats (0, 1, 1A, 1B, 1C, 2, 2A, 2B, 2C, 3, 3A) multi-functional by enabling them to convey both traditional scheduling information and RE pairing method information. This universality approach allows the system to maintain adaptability while minimizing additional signaling overhead, as the same fields serve multiple purposes rather than requiring separate dedicated fields.
Data Source
AI summary
A method for receiving a downlink signal according to a Demodulation Reference Signal (DMRS)-based transmission scheme, performed by a mobile terminal, in a wireless communication system is disclosed. The method includes receiving indication information indicating whether rate matching or timewise Resource Element (RE) pairing is allowed for REs that do not constitute frequency-wise RE pairs for Space Frequency Block Coding (SFBC) on symbols to which DMRSs are mapped in a Resource Block (RB) for a DL data channel, and decoding the downlink data channel, on assumption that the REs that do not constitute frequency-wise RE pairs for SFBC are rate-matched, or constitute time-wise RE pairs to which transmission data is mapped, according to the indication information.