Sub-terahertz Precoding Feedback for Receiver Complexity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems, particularly in the 5G NR technology, face challenges in efficiently managing sub-band fluctuations, leading to increased complexity and cost in receiver design due to frequency-selective channels, which are not effectively addressed by existing multiple-access technologies.
Innovation Solution
The implementation of a precoding feedback mechanism that allows wireless devices to measure and transmit channel flattening information, enabling the creation of a pseudo single tap channel by adjusting signal amplitudes and phases to maintain consistent amplitude across frequencies, thereby simplifying receiver design and reducing complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If frequency-selective channels are used in 5G NR wireless communication systems, then communication capacity and spectral efficiency are improved, but receiver complexity and cost increase due to the need for complex equalization and signal processing
Solution Approach 1:
The transmitter performs preliminary action by applying precoding weights to pre-equalize the frequency-selective channel response before signal transmission. This pre-processing at the transmitter side compensates for the frequency-selective fading effects, transforming the challenging frequency-selective channel into an effectively flat channel that requires minimal reception processing.
Solution Approach 2:
The system employs feedback mechanisms where the receiver estimates channel characteristics and feeds back information to the transmitter. The transmitter uses this feedback to adaptively adjust precoding weights, enabling continuous optimization of channel equalization and maintaining communication efficiency while reducing receiver complexity requirements.
2Productivity
If multiple-access technologies are used to share system resources, then spectrum utilization is improved, but sub-band fluctuations increase leading to greater receiver complexity
Solution Approach 1:
The transmitter applies precoding weights in advance to compensate for sub-band fluctuations caused by frequency-selective channels and multiple-access operations. By pre-equalizing the channel response before transmission, the system maintains flat sub-band characteristics even when multiple users share resources, eliminating the need for complex reception equalization.
Solution Approach 2:
The system dynamically adjusts precoding weights as a parameter to compensate for channel variations and sub-band fluctuations. By changing the precoding parameters based on channel state information, the system maintains optimal signal characteristics across different sub-bands while supporting multiple-access operations, thereby reducing receiver processing requirements.
3Adaptability or versatility
If existing multiple-access technologies are used, then system resource sharing is achieved, but frequency-selective channels cause increased sub-band fluctuations that require complex receiver processing
Solution Approach 1:
The transmitter performs preliminary channel equalization by applying precoding weights before signal transmission. This pre-processing action flattens the frequency-selective channel response and compensates for sub-band fluctuations, transforming the channel into an effectively flat channel that requires minimal reception processing even when multiple users share resources.
Solution Approach 2:
The precoding weights act as an intermediary mechanism between the frequency-selective channel and the receiver. By introducing this intermediate equalization layer at the transmitter side, the system neutralizes the harmful frequency-selective effects before they reach the receiver, allowing simple single-tap receivers to handle multiple-access scenarios effectively.
Data Source
AI summary
Aspects presented herein may enable a receiving device to receive high frequency signals with a simpler receiver to reduce the overall complexity and cost associated with the receiver. In one aspect, an apparatus receives a reference signal from a second wireless device. The apparatus measures amplitude and phase of the reference signal relative to a set point. The apparatus transmits channel flattening information in a precoding feedback to the second wireless device, the precoding feedback including at least a difference between the amplitude of the reference signal and the set point for a sub-band.