Transmission Control Device Layer-Based Calibration
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Solution Overview
Problem
In radio communication systems employing time division duplex (TDD), the accuracy of calibration between transmission points (TPs) decreases due to interference and temporal variations in radio channels, leading to unreliable channel estimation, especially when test signals are transmitted and received at coinciding or significantly differing timings.
Innovation Solution
A transmission control device allocates radio resources for the transmission and reception of calibration signals consecutively on a time axis to transmission points belonging to adjacent layers, sequentially switching layers to prevent interference and temporal variations, thereby enhancing calibration accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If test signals are transmitted and received between transmission points at coinciding timings, then calibration can be performed efficiently, but interference occurs and calibration accuracy decreases
Solution Approach 1:
The patent segments the calibration process by introducing layer-based grouping of transmission points. TPs are divided into multiple layers, and calibration signals are transmitted in a segmented manner where TPs in different layers transmit at different timings. This segmentation prevents simultaneous transmission interference while maintaining calibration efficiency across all TP pairs.
Solution Approach 2:
The patent implements periodic action through time-division multiplexing of calibration signals across different layers. Each layer transmits calibration signals in periodic time slots, ensuring that TPs in adjacent layers transmit at different timings. This periodic transmission pattern eliminates interference while systematically covering all TP pairs for calibration.
2Measurement precision
If test signals are transmitted and received at significantly differing timings, then interference is avoided, but temporal variations in radio channels increase leading to decreased calibration accuracy
Solution Approach 1:
The patent optimizes the time difference parameter between calibration signal transmissions in adjacent layers. By carefully controlling the timing offset to be neither zero (which causes interference) nor excessively large (which causes temporal variation), the system achieves optimal calibration accuracy. This parameter optimization balances interference avoidance with temporal stability.
3Measurement precision
If sequential time-division transmission is performed across all TP pairs, then interference is avoided, but radio resources are wasted and calibration efficiency decreases
Solution Approach 1:
The patent merges multiple TP calibrations that would otherwise require sequential time-division transmission by introducing layer-based parallel processing. TPs within the same layer can perform calibration simultaneously, and layers are sequentially activated. This merging approach significantly reduces the total calibration time and radio resource consumption compared to strict sequential transmission.
Solution Approach 2:
The patent adds a layer dimension to the traditional sequential TP calibration approach. Instead of calibrating TPs one after another in a single dimension (time), the system organizes TPs into multiple layers and calibrates across this new dimensional structure. This allows parallel calibration within layers while maintaining temporal separation between layers, achieving both efficiency and accuracy.
Data Source
AI summary
A transmission control device includes a memory; and a processor connected to the memory and configured to: specify layers corresponding to a number of hops of a link generated between a plurality of transmission points each of which wirelessly transmits a signal; and allocate radio resources which are used for transmission and reception of the signal and consecutive on a time axis to transmission points belonging to adjacent layers while sequentially switching the specified layers.