MIMO Precoding for Spatial Multiplexing
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Solution Overview
Problem
In MIMO systems, the Open Loop Transmit Diversity (OLTD) transmission solution causes interference among UEs, preventing spatial multiplexing on time-frequency resources and affecting system throughput.
Innovation Solution
The method involves preprocessing spatial flows to generate precoded data flows, which are then transmitted and restored by the receive end device, allowing multiple UEs to perform spatial multiplexing on time-frequency resources, improving system throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If OLTD transmission solution is used to provide cell-level signal coverage, then signal reliability is improved, but spatial multiplexing capability deteriorates and system throughput is reduced
Solution Approach 1:
The patent applies dynamic switching between different transmission modes (OLTD for coverage, precoding for throughput) based on channel conditions and UE distribution. The base station dynamically adjusts the transmission solution selected for each UE, enabling the system to adapt between reliability-oriented and throughput-oriented operations.
Solution Approach 2:
The patent changes the transmission parameters by introducing precoding matrices and adjusting the number of spatial layers based on channel state information. This allows the system to transform from a static OLTD mode to a flexible mode that can achieve both coverage and spatial multiplexing by adjusting parameters like precoding matrix indicator (PMI) and rank indicator (RI).
2Reliability
If OLTD transmission solution is used to ensure coverage, then signal quality is improved, but interference among UEs increases
Solution Approach 1:
The patent applies different transmission solutions to different UEs based on their local channel conditions and spatial locations. Instead of uniformly applying OLTD to all UEs, the system selectively applies precoding to specific UEs to minimize their interference impact on others, while maintaining OLTD for UEs that benefit from coverage enhancement.
Solution Approach 2:
The patent converts the potential harm of multi-UE transmissions by using precoding to steer beams in specific directions, thereby transforming what would be interference into directed signal energy. The precoding process converts random interference into controlled, directional transmission that can be managed through spatial separation.
3Productivity
If multiple UEs transmit simultaneously on time-frequency resources, then spatial multiplexing is achieved, but interference management complexity increases
Solution Approach 1:
The patent introduces precoding matrices as an intermediary mechanism that simplifies multi-UE interference management. By applying precoding before transmission, the system creates orthogonal or near-orthogonal spatial channels that naturally reduce interference, eliminating the need for complex real-time interference coordination between UEs.
Solution Approach 2:
The patent performs preliminary precoding processing based on pre-acquired channel state information before actual data transmission. This preliminary action of calculating and applying precoding matrices in advance simplifies the subsequent transmission process and reduces the complexity of real-time interference management during active spatial multiplexing.
Data Source
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Figure 3
Figure 4-1A
AI summary
This application discloses a data sending method, a data receiving method, a device, a system, and a storage medium, and pertains to the field of communications technologies. The method includes: precoding at least two first preprocessed spatial flows to obtain a plurality of precoded data flows, where the at least two first preprocessed spatial flows are obtained by preprocessing a first original spatial flow; and transmitting the plurality of precoded data flows. This application helps to resolve a problem that a plurality of UEs cannot perform spatial multiplexing on a time-frequency resource and a system throughput is affected, helps the plurality of UEs to perform spatial multiplexing on the time-frequency resource, and improves the system throughput. This application is used for data transmission.