Interleaved Multi-User Block Transmission With Non-Coherent Signal Separation
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Solution Overview
Problem
Current multi-user access schemes in wireless communication, particularly in LTE and 5G networks, face challenges with high pilot contamination and overhead due to coherent signaling, especially in scenarios with high mobility and large numbers of users, leading to inefficiencies in channel estimation and spectral usage.
Innovation Solution
The implementation of multi-user frequency-division multiplexing using modulation on conjugate-reciprocal zeros (MOCZ) with interleaved frequency-division multiplexing techniques, which allows for non-coherent communication and efficient separation of user signals in the frequency domain, reducing the need for pilot signals and enhancing spectral efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If coherent signaling with pilot signals is used for channel estimation, then channel estimation accuracy is improved, but pilot contamination and overhead increase significantly
Solution Approach 1:
The patent extracts and removes the pilot signal component from the communication system by transitioning to non-coherent detection. This eliminates the need for pilot signals entirely, resolving the contradiction by taking out the harmful element (pilot overhead) while maintaining channel estimation capability through alternative means (energy detection and combinatorial modulation).
Solution Approach 2:
The patent replaces the mechanical/coherent signaling system with a non-coherent detection system. Instead of using pilot signals and coherent channel estimation, the system uses energy detection and combinatorial modulation schemes that do not require channel state information, thereby eliminating pilot overhead while maintaining measurement capability.
2Adaptability or versatility
If coherent signaling is used in high mobility scenarios with large numbers of users, then user access capability is improved, but pilot contamination and system overhead increase
Solution Approach 1:
The non-coherent detection system serves itself by using energy detection and signal structure analysis rather than external pilot signals. Each user's signal carries its own identification through combinatorial modulation patterns, eliminating the need for separate pilot resources and enabling scalable user access without increasing overhead.
Solution Approach 2:
The patent changes the fundamental parameter of detection methodology from coherent to non-coherent. This parameter change allows the system to maintain user access capability through alternative signal differentiation methods (combinatorial modulation patterns) while eliminating pilot signal requirements entirely.
3Reliability
If conventional frequency-division multiplexing is used, then user signal separation is achieved, but peak-to-average power ratio is high and interference occurs
Solution Approach 1:
The patent applies preliminary time-shifting to user signals before transmission. This time-domain offset allows signals from different users to be separated in time, eliminating the need for high PAPR mitigation techniques and reducing interference while maintaining reliable user signal separation through simple time-domain processing.
4Measurement precision
If more pilot signals are used for channel estimation, then channel estimation accuracy is improved, but spectral efficiency decreases
Solution Approach 1:
The patent extracts and removes pilot signals from the system by implementing non-coherent detection. This eliminates the trade-off entirely by taking out the element that causes spectral efficiency loss while maintaining measurement capability through energy detection and combinatorial modulation schemes that use the data signals themselves for identification.
Data Source
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AI summary
A computer-implemented method for multi-user multiplexing for block transmissions by an electronic device includes generating a user signal that includes a number of first samples in time domain. The number of first samples are generated based on a discrete-time baseband signal and a predetermined guard period. A discrete Fourier transform (DFT) operation is performed on the number of first samples to obtain a number of second samples in frequency domain. An interleaving operation is performed on the number of second samples to obtain a number of third samples in frequency domain. An inverse-DFT (IDFT) operation is performed on the number of third samples to obtain a number of fourth samples in time domain. A time shifting is performed on the number of fourth samples to obtain a number of shifted fourth samples. A block transmission is sent using the number of shifted fourth samples.