Transmission Symbol Arrangement for Reducing Mutual Interference
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Solution Overview
Problem
In digital communications, simultaneous transmission of pilot signals by multiple devices on the same network resources leads to mutual interference, degrading channel estimation performance and limiting the number of simultaneous user equipment (UE) transmissions.
Innovation Solution
A method and system for arranging transmission symbols, where each transmitting device determines a spreading pattern and places its pilot signal into specific resources according to that pattern, reducing mutual interference by exploiting sparsity in the frequency domain, allowing pilot signals to be transmitted only on tones used for data transmission, thereby increasing the number of simultaneous UE transmissions without degrading channel estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple transmitting devices simultaneously transmit pilot signals on the same network resources, then the number of simultaneous UE transmissions increases, but mutual interference occurs and channel estimation performance decreases
Solution Approach 1:
The patent segments the frequency domain resources by dividing the available subcarriers into different groups or patterns. Each transmitting device is assigned a specific spreading pattern that determines which frequency resources its pilot signal occupies. This segmentation of frequency resources allows multiple devices to transmit simultaneously without complete overlap, reducing mutual interference while maintaining the ability to support multiple simultaneous transmissions
Solution Approach 2:
The patent applies local quality by assigning different spreading patterns to different transmitting devices, creating localized variations in resource allocation. Each device's pilot signal is concentrated in specific frequency regions according to its assigned pattern, rather than uniformly distributed. This localized resource allocation reduces interference in critical frequency regions while allowing flexible support for multiple simultaneous transmissions
2Reliability
If pilot signals are transmitted on all frequency resources, then channel estimation coverage is maximized, but mutual interference increases when multiple devices transmit simultaneously
Solution Approach 1:
The patent extracts the pilot signal transmission from uniform full-frequency coverage and relocates it to specific frequency patterns determined by spreading sequences. Instead of transmitting pilot signals across all frequency resources, each device's pilot is extracted and placed only in the frequency positions specified by its spreading pattern. This reduces the overlap and mutual interference between multiple devices while maintaining reliable channel estimation through the distributed pattern coverage
Solution Approach 2:
The patent introduces a new dimension of resource allocation by using spreading patterns in the frequency domain. Rather than allocating frequency resources in a simple one-dimensional manner, the spreading patterns create a more complex multi-dimensional resource structure where pilot signals are distributed across frequency according to specific patterns. This dimensional approach allows better separation of multiple devices' pilot signals, reducing interference while maintaining coverage
Data Source
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Figure 3a~3b
AI summary
A method for operating a first device includes determining a spreading pattern associated with the first device, placing a pilot signal associated with the first device into resources of a first transmission symbol in accordance with the spreading pattern, and transmitting the first transmission symbol to a second device