Channel State Information Feedback Using Time Domain Components
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In extreme bandwidth wireless communication systems, such as 5G networks, the transmission of full channel state information (CSI) for multiple channels consumes significant resources, especially when reciprocal channel estimation is not possible, leading to inefficient beamforming and resource utilization.
Innovation Solution
The method involves selecting a subset of non-frequency domain components, specifically time domain components, of channel responses and transmitting CSI based on these selected components, which reduces the resources needed for transmission while maintaining effective beamforming gains by identifying and quantizing key components like location, phase, and amplitude.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If full channel state information is transmitted for multiple channels, then beamforming accuracy is improved, but resource consumption increases significantly
Solution Approach 1:
The patent extracts only the essential time domain components from the full channel response, specifically identifying and transmitting parameters related to dominant propagation paths (delay, Doppler shift, amplitude, phase) rather than transmitting complete channel state information across all frequency subcarriers. This extraction approach maintains beamforming accuracy by preserving the most significant channel characteristics while dramatically reducing feedback overhead.
Solution Approach 2:
The patent transforms the channel representation from frequency domain to time domain, changing the parameters being transmitted from frequency-specific channel gains to time-domain propagation path parameters. By representing the channel response as a sum of delayed and Doppler-shifted versions of a reference signal, the system transmits a compact set of parameters (delay values, Doppler values, amplitudes, phases) that fully characterize the multipath channel without requiring full CSI feedback.
2Quantity of substance
If time domain components are selected and transmitted instead of full CSI, then resource usage is reduced, but channel estimation accuracy may deteriorate
Solution Approach 1:
The patent changes the representation parameters from frequency-domain channel gains to time-domain propagation path parameters. By modeling the channel as a superposition of delayed and Doppler-shifted reference signals, the system captures the essential physical characteristics of wireless propagation (multipath delays, Doppler shifts due to mobility) in a compact parameter set that enables accurate channel reconstruction.
Solution Approach 2:
The patent introduces dynamic parameters (Doppler shifts) to account for time-varying channel conditions caused by user mobility. The channel response is represented as a sum of time-varying components with different Doppler shifts, allowing the system to adapt to changing propagation conditions while maintaining accurate channel estimation with reduced feedback overhead.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Techniques are described for wireless communication. One method includes identifying a plurality of channel responses corresponding to a plurality of channels. Each channel of the plurality of channels corresponds to a pairing of a transmit antenna with a receive antenna. Each channel response of the plurality of channel responses corresponds to a plurality of tone subsets. The method also includes selecting, for each channel of the plurality of channels, a subset of non-frequency domain components of the channel response for the channel, and transmitting, for at least one channel of the plurality of channels, at least one subset of channel state information (CSI). The at least one subset of CSI is based at least in part on at least one of the selected subsets of non-frequency domain components.