Space-Delay Precoding for Wireless Feedback Overhead Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems face significant challenges with high feedback overhead in precoding, particularly in multi-antenna systems, which can lead to increased complexity and reduced performance due to the need for frequent channel state information feedback.
Innovation Solution
The implementation of space-delay precoding with reduced feedback, where complex precoder coefficients and delays are determined and fed back to the transmitter, allowing for direction and delay-based beamforming, thereby enhancing performance in terms of mutual information and rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional precoding with full channel state information feedback is used, then communication performance is improved, but feedback overhead increases significantly
Solution Approach 1:
The patent extracts only the essential channel characteristics (delay values and corresponding precoder coefficients) from the full channel state information. By identifying and feeding back only the dominant delay components rather than complete channel data, the system reduces feedback overhead while preserving the most critical information needed for effective precoding at mmWave frequencies
Solution Approach 2:
The patent changes the feedback parameters from complete channel state information to a simplified set consisting of delay values and associated precoder coefficients. This parameter transformation maintains the essential precoding functionality while dramatically reducing the amount of feedback data required, especially beneficial in mmWave systems with sparse multipath characteristics
2Measurement precision
If more channel state information is fed back for precise precoding, then precoding accuracy is improved, but system complexity increases
Solution Approach 1:
The patent extracts only the dominant delay components and their corresponding precoder coefficients from the full channel state information. This extraction approach maintains precoding accuracy by focusing on the most significant channel characteristics while avoiding the complexity of processing and feedback of complete channel data
Solution Approach 2:
The patent applies partial action by feeding back only the necessary portion of channel information (dominant delays and associated coefficients) rather than complete channel state information. This partial feedback approach achieves sufficient precoding accuracy for mmWave systems without the excessive complexity of full channel feedback
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A receiver is disclosed which receives and processes a radio signal received via a frequency selective radio channel from a transmitter employing a plurality of transmit antennas. The receiver determines, based on the received signal, complex precoder coefficients and delays of respective space-delay precoders for each layer and transmit antenna at the transmitter so as to achieve a predefined property for a communication over the radio channel, each space-delay precoder modeling or defining for the associated transmit antenna a plurality of cyclic filters delaying and weighting a signal to be transmitted with the corresponding precoder delays and complex precoder coefficients, respectively, and feeds back to the transmitter the determined delays explicitly or implicitly and the determined complex precoder coefficients explicitly or implicitly, the transmitter precoding the signals to be transmitted to the receiver using the fed back delays and complex precoder coefficients.