SC-FDM Interference Estimation via Modulation Symbols
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Solution Overview
Problem
Wireless communication systems using shared radio frequency spectra face interference challenges, particularly with bursty interference, which affects the decoding of SC-FDM symbol streams, especially in scenarios where access points may transmit without receiving channel reservation signals.
Innovation Solution
The technique involves inserting channel or interference estimation modulation symbols into SC-FDM symbol streams, performing discrete Fourier transforms, and using tone mapping and inverse fast Fourier transforms to estimate and subtract interference, enabling reliable decoding even with bursty interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If SC-FDM symbol streams are transmitted over shared radio frequency spectrum, then data transmission capacity is enhanced and service coverage is extended, but bursty interference occurs affecting decoding reliability
Solution Approach 1:
The patent applies preliminary action by inserting channel estimation modulation symbols into the SC-FDM symbol stream before transmission. These known symbols are placed at specific positions in advance to enable the receiver to estimate and compensate for bursty interference during decoding, thereby maintaining reliability while using shared spectrum for enhanced capacity
2Measurement precision
If channel estimation modulation symbols are inserted into SC-FDM symbol streams, then interference estimation accuracy is improved, but overhead increases
Solution Approach 1:
The patent applies local quality by strategically placing channel estimation modulation symbols at specific positions within the SC-FDM symbol stream rather than uniformly distributing them. This selective placement optimizes interference estimation accuracy at critical positions while minimizing the overall overhead of estimation symbols
Data Source
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AI summary
Techniques are described for wireless communication. A first method includes inserting channel or interference estimation modulation symbols into a sequence of data modulation symbols; performing a discrete Fourier transform (DFT) on a group of modulation symbols in the sequence of data modulation symbols, the group of modulation symbols including at least one of the channel or interference estimation modulation symbols; and generating a single-carrier frequency domain modulated (SC-FDM) symbol stream based at least in part on an output of the DFT. A second method includes performing an IDFT on a tone-demapped output of a DFT for each of at least one SC-FDM symbol stream, to recover a plurality of data modulation symbols and channel or interference estimation modulation symbols for each of the at least one SC-FDM symbol stream; estimating interference based at least in part on the channel or interference estimation modulation symbols; and decoding the data modulation symbols based at least in part on the estimated interference.