DCS Phase Coding for Low-CSI Wireless Communication
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Solution Overview
Problem
Current wireless communication systems using digitally controllable scatterers (DCS) face challenges with large Channel State Information (CSI) requirements and feedback overhead due to the complexity of large channel matrices and the need for CSI estimation and feedback, which can be detrimental in scenarios with low channel coherence times.
Innovation Solution
A Space Time Block Code (STBC) is applied to DCS configuration, allowing for transmitter-coded signal generation and receiver processing without requiring CSI feedback or estimation of large channel matrices, using a STDC matrix that does not depend on the number of scattering elements, reducing overhead and enhancing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If algorithms for channel programming using DCS are implemented, then wireless communication performance is improved, but large CSI requirements and feedback overhead are incurred
Solution Approach 1:
The patent extracts and eliminates the requirement for large-scale CSI feedback by using a random DCS phase configuration. Instead of computing and feeding back full channel matrices (which require Sd elements), the system only requires minimal feedback about channel quality, reducing the feedback overhead from O(Sd) to O(1) while maintaining communication performance through opportunistic beamforming effects
Solution Approach 2:
The patent changes the DCS phase configuration parameter from a deterministic CSI-based approach to a random configuration approach. By randomizing the phase shifts of scattering elements, the system transforms the channel into a programmable medium without requiring precise CSI knowledge, thereby eliminating the need for large feedback matrices while preserving the ability to improve wireless communication
2Adaptability or versatility
If DCS phase configuration based on CSI is implemented, then channel control is achieved, but complexity of CSI acquisition increases
Solution Approach 1:
The patent enables the DCS to self-configure its phase shifts randomly without requiring external CSI computation or control. Each scattering element independently adopts a random phase configuration, eliminating the need for complex CSI acquisition algorithms, large matrix computations, or sophisticated coordination between transmitter and receiver, thereby significantly reducing system complexity while maintaining adaptability
3Manufacturing precision
If feedback of channel information is implemented, then DCS configuration accuracy is improved, but feedback delay increases
Solution Approach 1:
The patent performs the DCS phase configuration action in advance by randomly configuring phases before channel measurement and feedback. This preliminary random configuration eliminates the need for subsequent feedback-based adjustments, as the random phases are already in place to create beneficial propagation paths. The system accepts minimal quality feedback rather than full channel state feedback, thereby reducing feedback delay while maintaining configuration effectiveness
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables efficient channel estimation and signal combining at the receiver, reduces feedback requirements, and allows for flexible channel generation without the need for CSI, suitable for low complexity devices like IoT devices.
Implementation Method 1
Each scattering element provides the ability of controlling the phase of its scattered signal
Implementation Method 2
a DCS is implemented using a large number, typically hundreds or thousands, of reflective or scattering elements
Data Source
AI summary
The disclosure provides a wireless communication system, comprising at least one DCS with a surface that comprises scattering elements having a controllable phase shift, at least one transmitter configured to transmit a coded radiofrequency signal to at least one receiver during a plurality of time slots, and a controller. The controller controls the at least one transmitter, based on a space time DCS code (STDC) to generate the coded radiofrequency signal during the plurality of time slots. The controller further controls, based on the STDC, the set of scattering elements of the at least one DCS during the plurality of time slots. The STDC depends on a total number of the at least one DCS and a maximum number of the plurality of time slots Tmax.