User Equipment Location Feedback for Channel State Information
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Solution Overview
Problem
Channel state information (CSI) feedback in broadband mobile radio systems is challenging due to high time and frequency variance, leading to significant feedback overhead, especially in cooperative antenna systems where accurate CSI estimation is crucial for coherent precoding, but existing techniques struggle with high accuracy and latency.
Innovation Solution
Instead of feeding back the radio channel itself, user equipment (UE) transmits its location to the network element, allowing the network to determine CSI using local surrounding data and raytracing algorithms, which reduces feedback overhead and improves prediction accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If traditional CSI feedback techniques (interpolation, codebook based precoding, tracking algorithms) are used, then feedback overhead is reduced to some extent, but CSI accuracy deteriorates due to high time and frequency variance in fast moving UEs
Solution Approach 1:
The patent introduces UE location as an intermediary parameter that mediates between the UE and the network element. Instead of directly feedbacking CSI or using complex tracking algorithms, the UE's location information serves as a simple mediator that enables the network element to determine CSI through raytracing algorithms, resolving the contradiction between feedback overhead reduction and CSI accuracy
Solution Approach 2:
The patent changes the fundamental parameter from which CSI is derived. Instead of using time-varying channel measurements or frequency-domain parameters, the system uses spatial location parameters (UE position) combined with static surrounding data to determine CSI through raytracing, fundamentally changing how CSI is obtained and reducing feedback requirements
2Quantity of substance
If codebook based precoding with tracking algorithms is applied, then feedback overhead is reduced, but system performance deteriorates due to latency and inability to handle high time variance
Solution Approach 1:
The patent applies preliminary action by pre-storing surrounding data (building vectors, obstacle information) in the network element before the UE actually needs CSI. This allows the network element to immediately calculate CSI using raytracing algorithms when UE location is known, eliminating the need for continuous tracking algorithms and reducing latency while maintaining performance
3Quantity of substance
If subspace based feedback reduction techniques are used, then feedback is adapted to subspace dimensions, but feedback overhead reduction is limited when full dimension feedback is required
Solution Approach 1:
The patent extracts only the essential information needed for CSI determination - the UE's location parameters - from the potentially vast amount of data that could be feedbacked. By taking out just the location information and using it with pre-stored surrounding data, the system achieves feedback reduction while maintaining full dimensional CSI accuracy through raytracing calculations
Data Source
AI summary
The proposed methods and devices provide a new technique for feeding back CSI information of a channel between a network element and a user equipment to the network element by feeding back a location of the user equipment. The new technique opens completely new options for multi user scheduling and channel prediction. According to embodiments, a proposed user equipment configuration is indicated to the user by the user equipment.