DMRS Port Orthogonality via OCC Merging
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Solution Overview
Problem
The existing mobile communication systems face inter-layer interference issues due to an excessive number of transmission layers, which exceeds the capacity of orthogonal demodulation reference signal (DMRS) ports.
Innovation Solution
The proposed solution involves a communication method where a receiving device receives DMRS signals from multiple DMRS ports using overlapping time-frequency resources, ensuring that the orthogonal cover codes of these signals are orthogonal to each other, thereby avoiding interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the quantity of transmission layers is increased to improve system throughput, then productivity is improved, but the number of orthogonal DMRS ports becomes insufficient causing inter-layer interference
Solution Approach 1:
The patent merges the time-frequency resources of the first DMRS port with a subset of resources from the second DMRS port. The first DMRS uses a first subset of time-frequency resources, while the second DMRS uses a second subset that overlaps with the first subset. This resource merging allows both DMRS ports to share the same time-frequency grid while maintaining orthogonality through different OCC assignments, thereby supporting more transmission layers without requiring additional dedicated resources.
Solution Approach 2:
The patent changes the OCC parameter to achieve orthogonality between DMRS ports sharing overlapping time-frequency resources. Specifically, the first DMRS port uses a first OCC while the second DMRS port uses a second OCC that is orthogonal to the first OCC. This parameter change in the OCC domain enables the system to support more transmission layers (improving productivity) while maintaining the orthogonality required for reliable channel estimation (maintaining reliability).
2Quantity of substance
If additional orthogonal DMRS ports are added to support more layers, then the number of multiplexing layers is improved, but additional time-frequency resource overhead is required
Solution Approach 1:
The patent combines the time-frequency resources of multiple DMRS ports by allowing the first DMRS port and second DMRS port to share overlapping resources. The first time-frequency resources are a proper subset of the second time-frequency resources, meaning both ports can be multiplexed within the same resource grid without requiring additional dedicated resources for each port.
Solution Approach 2:
The patent moves the orthogonality differentiation from the time-frequency domain to the code domain by using different OCCs. Instead of allocating separate time-frequency resources for each DMRS port (which would increase overhead), the system maintains orthogonality through OCC assignments in the code domain, allowing multiple ports to share the same time-frequency resources efficiently.
Data Source
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AI summary
This application provides a communication method and apparatus, and relates to the field of communication technologies. This application is configured to reduce inter-layer interference between DMRS ports caused by an excessively large quantity of transmission layers between a terminal device and a network device. The method includes: A receiving device receives a first DMRS from a first demodulation reference signal DMRS port by using a first time-frequency resource, and receives a second DMRS from a second DMRS port by using a second time-frequency resource, where the first time-frequency resource is a part of time-frequency resources in the second time-frequency resource, and an orthogonal cover code OCC of the first DMRS is orthogonal to an OCC corresponding to the first time-frequency resource in an OCC of the second DMRS.