ACK Resource Partitioning for SDMA Orthogonality
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems face inefficiencies in transmitting acknowledgement (ACK) information, particularly in multiple-input multiple-output (MIMO) data transmissions, where ACK resources are not effectively utilized, leading to potential loss of orthogonality and increased peak-to-average ratio (PAR) in power amplifiers.
Innovation Solution
The system partitions ACK resources using frequency division multiplexing (FDM) or time division multiplexing (TDM) to associate each layer of MIMO data transmission with a respective portion of ACK resources, allowing UEs to send ACK information on specific resource elements, thereby preserving orthogonality and reducing PAR.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If ACK resources are shared among multiple UEs without partitioning, then resource utilization is improved, but orthogonality is lost and PAR increases
Solution Approach 1:
The patent segments ACK resources into distinct portions allocated to different UEs or layers. Each UE is assigned specific resource elements (REs) for ACK transmission, preventing collisions and maintaining orthogonality. This segmentation resolves the contradiction by allowing multiple UEs to share ACK resources efficiently while preserving the orthogonality needed for reliable detection.
2Productivity
If ACK information is multiplexed with data on the same resources, then resource efficiency is improved, but PA power derating increases
Solution Approach 1:
The patent extracts ACK information from the data transmission resources and assigns it to dedicated ACK resource elements. This separation allows the power amplifier to operate at optimal power levels for data transmission without the need for power derating that would occur if ACK and data were multiplexed on the same resources, thus resolving the contradiction between resource efficiency and power consumption.
3Reliability
If reserved time-frequency resources are used for ACK transmission, then orthogonality is maintained, but resource flexibility is reduced
Solution Approach 1:
The patent implements dynamic ACK resource allocation where the specific time-frequency resources for ACK transmission can be flexibly assigned based on system conditions, UE requirements, and layer configurations. This dynamic approach maintains orthogonality through structured resource partitioning while providing the flexibility to adapt to different transmission scenarios, resolving the contradiction between reliability and adaptability.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Techniques for transmitting acknowledgement (ACK) information in a wireless communication system are described. The system supports data transmission to multiple user equipments (UEs) on the same downlink resources with spatial division multiple access (SDMA). A base station sends a data transmission with multiple (M) layers to M UEs. The downlink resources used for the data transmission are associated with ACK resources used to send ACK information for the data transmission. The ACK resources may be partitioned into M portions, e.g., based on frequency division multiplexing (FDM). Each of the M layers is associated with a respective portion of the ACK resources. A recipient UE for each layer sends ACK for that layer on the associated portion of the ACK resources. For each ACK resource portion, one or more pilot symbols may be sent on one or more resource elements, and ACK symbols may be sent on remaining resource elements.