Modulation Symbol Dimension Conversion for Doppler Resistance
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Solution Overview
Problem
Existing wireless communication systems, such as OFDM, are sensitive to Doppler frequency offset in high-speed mobile scenarios, leading to increased bit error rates and limited application in environments like aircraft and high-speed rail communications, while OTFS modulation introduces high computational overhead and system delay, making it unsuitable for practical implementation on devices like smartphones.
Innovation Solution
An electronic device and communication method that perform pre-processing and post-processing operations involving dimension-increasing and dimension-decreasing conversions on modulation symbols, coupled with specific transformations, to effectively counter Doppler effects while maintaining low implementation complexity and system delay.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If OFDM modulation is used in high-speed mobile scenarios, then the system can achieve broadband wireless communication, but the Doppler Effect will seriously deteriorate the performance and increase bit error rate
Solution Approach 1:
The patent segments the modulation process into multiple dimensions by converting one-dimensional modulation symbols into two-dimensional symbol blocks, then applying transformations across both time and frequency domains. This segmentation allows the system to handle Doppler effects more effectively by distributing information across multiple dimensions rather than relying on single-carrier frequency allocation.
Solution Approach 2:
The patent introduces a second dimension by transforming one-dimensional modulation symbol sequences into two-dimensional modulation symbol blocks. This dimensionality change enables the system to counteract Doppler frequency offset by processing symbols across both time and frequency dimensions, thereby improving reliability in high-speed mobile scenarios while maintaining broadband communication capability.
2Reliability
If OTFS modulation is used to counter Doppler frequency offset, then diversity gain is achieved, but computational overhead and system delay increase significantly
Solution Approach 1:
The patent applies partial transformation by performing dimension-increasing conversion on only the necessary portion of modulation symbols rather than requiring joint processing of all symbols across multiple OFDM symbol intervals. This partial action approach achieves sufficient diversity gain to counter Doppler effects while significantly reducing computational overhead compared to full OTFS processing.
Solution Approach 2:
The patent performs preliminary dimension-increasing conversion and transformation operations on modulation symbols before transmission, preparing the signal structure in advance to inherently resist Doppler effects. This preliminary action eliminates the need for complex post-processing and joint processing across multiple symbol intervals, thereby reducing both computational overhead and system delay.
3Reliability
If OTFS modulation is used to counter Doppler frequency offset, then diversity gain is achieved, but system delay increases making it unsuitable for practical systems
Solution Approach 1:
The patent segments the processing into independent dimension-increasing conversion and transformation steps that can be performed on individual modulation symbol blocks rather than requiring accumulation of multiple OFDM symbol intervals. This segmentation enables real-time processing without introducing endogenous system delay, making the solution suitable for practical high-speed mobile communication systems.
4Productivity
If multiple frequency domain subcarriers are allocated in advance for OFDM transmission, then broadband communication is achieved, but sensitivity to Doppler frequency offset increases
Solution Approach 1:
The patent mitigates Doppler frequency offset sensitivity by transforming the one-dimensional frequency-domain subcarrier allocation into two-dimensional time-frequency symbol blocks. This dimensionality change allows the system to maintain broadband communication capability through multiple subcarriers while reducing sensitivity to Doppler effects by distributing information across both time and frequency dimensions through the transformation process.
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
The proposed solution improves communication performance in high-speed mobile scenarios by reducing bit error rates and system complexity, making it suitable for implementation in devices such as smartphones without introducing significant delays.
Implementation Method 1
performing a dimension-increasing conversion to convert the first one-dimensional sequence of modulation symbols into a first multi-dimensional modulation symbol block
Implementation Method 2
transforming the first multi-dimensional modulation symbol block into a second multi-dimensional modulation symbol block with a first transformation, wherein the first transformation couples each symbol in the first multi-dimensional modulation symbol block with each other
Implementation Method 3
performing a dimension-decreasing conversion to convert the second multi-dimensional modulation symbol block into a second one-dimensional sequence of modulation symbols
Data Source
AI summary
An electronic device and communication method are disclosed. The electronic device comprises a processing circuit configured to perform a pre-processing operation on a first one-dimensional sequence of modulation symbols, the pre-processing operation including: performing a dimension-increasing conversion to convert the first one-dimensional sequence of modulation symbols into a first multi-dimensional modulation symbol block; transforming the first multi-dimensional modulation symbol block into a second multi-dimensional modulation symbol block with a first transformation, wherein the first transformation couples each symbol in the first multi-dimensional modulation symbol block with each other; and performing a dimension-decreasing conversion to convert the second multi-dimensional modulation symbol block into a second one-dimensional sequence of modulation symbols, wherein the dimension-decreasing conversion is an inverse process of the dimension-increasing conversion. The processing circuit is also configured to transmit the second one-dimensional sequence of modulation symbols.