Alamouti Coded DMRS for Reduced Interference Estimation Complexity
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Solution Overview
Problem
In wireless communications, terminal devices face complexity in demodulating data due to varying transmission schemes, leading to increased interference estimation and demodulation complexity, especially when interfered with by other terminal devices using different transmission schemes.
Innovation Solution
The implementation of Alamouti coding for both demodulation reference signals (DMRS) and data in the space domain and frequency or time domain ensures that the channel experienced by the DMRS is consistent with the channel experienced by the data, allowing for accurate equivalent channel matrix estimation and reduced interference estimation complexity by aligning the processing of DMRS and data with the transmission scheme used by the terminal device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the terminal device estimates equivalent channel matrix by traversing various transmission schemes to handle interference from other terminal devices, then the demodulation accuracy is improved, but the interference estimation complexity and computational burden increase significantly
Solution Approach 1:
The patent extracts only the necessary information from interfering signals by identifying and utilizing the DMRS ports and transmission schemes of interfering terminal devices. Instead of analyzing all possible transmission schemes, the system selectively extracts interference characteristics from identified DMRS ports, significantly reducing computational complexity while maintaining demodulation accuracy.
Solution Approach 2:
The patent performs preliminary channel estimation using DMRS before data demodulation. By estimating the equivalent channel matrix using DMRS that undergo the same Alamouti coding as the data, the system prepares interference cancellation parameters in advance, enabling more efficient data demodulation without traversing various transmission schemes during the actual demodulation process.
2Adaptability or versatility
If different transmission schemes are used to adapt to different channel environments, then the system adaptability is improved, but the terminal device faces increased complexity in demodulating data across multiple schemes
Solution Approach 1:
The patent applies Alamouti coding universally to both DMRS and data transmission, creating a consistent processing framework that works across different transmission schemes. This universal approach allows the terminal device to demodulate data using the same channel estimation method regardless of the specific transmission scheme employed, reducing demodulation complexity while maintaining adaptability to different channel environments.
Solution Approach 2:
The patent changes the parameter of DMRS processing to match the data transmission scheme by applying the same Alamouti coding to DMRS as is applied to data. This parameter alignment ensures that the channel estimation accurately reflects the actual data transmission characteristics, enabling simplified demodulation across various transmission schemes without requiring separate processing for each scheme.
3Adaptability or versatility
If DMRS and data undergo different processing, then the flexibility in signal processing is improved, but the channel consistency between DMRS and data deteriorates, leading to inaccurate channel estimation
Solution Approach 1:
The patent applies the same Alamouti coding processing to both DMRS and data, creating homogeneity in the signal processing chain. This homogeneous processing ensures that the channel experienced by DMRS is consistent with the channel experienced by data, enabling accurate channel estimation. The system maintains processing flexibility by applying this consistent Alamouti coding across different transmission schemes and channel environments.
Data Source
AI summary
A terminal device receives a DMRS and data from a network device. The DMRS and the data undergo Alamouti coding in space domain and frequency domain, or the DMRS and the data undergo Alamouti coding in space domain and time domain, and a DMRS obtained through the Alamouti coding is mapped to a first DMRS port and a second DMRS port. A modulation symbol of the first DMRS port is related to a modulation symbol of the second DMRS port. The terminal device demodulates the data based on the DMRS. Therefore, the DMRS corresponds to a transmission scheme of the data, to help the terminal device demodulate the data. This can reduce interference estimation complexity of the terminal device.