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A new pilot shared method for saving bandwidth cost of OFDM
Shahid Ali1, Dongsheng Zheng1, Bingli Jiao2
1School of Electronics, Peking University, Beijing, 100871, P. R. China.
Scientific Reports
|February 24, 2024
Summary
This study reduces pilot tones in orthogonal frequency division multiplexing (OFDM) systems by leveraging channel coherent bandwidths (CCBs). This optimization maintains signal demodulation performance while improving spectral efficiency for wireless communication.
Area of Science:
- Electrical Engineering
- Wireless Communications
- Signal Processing
Background:
- Orthogonal frequency division multiplexing (OFDM) systems achieve high spectral efficiency using pilot tones for coherent demodulation.
- Conventional OFDM designs incur a bandwidth cost due to the number of pilot tones required.
Purpose of the Study:
- To reduce the number of pilot tones in OFDM systems without compromising signal demodulation performance.
- To enhance spectral efficiency by optimizing pilot allocation based on channel characteristics.
Main Methods:
- Utilizing the statistical properties of downlink channels and the concept of channel coherent bandwidths (CCBs).
- Allocating data within each user's CCB to accommodate minimized pilot spacing.
- Employing linear interpolation of channel frequency response and least squares (LS) for channel estimation.
Main Results:
- Demonstrated theoretical gains in ergodic capacities.
- Confirmed performance improvements through simulations.
- Proposed a method for sparser pilot allocation tailored to individual user CCBs.
Conclusions:
- Reduced pilot tones are feasible in OFDM systems by exploiting varying CCBs.
- The proposed method offers a more efficient use of bandwidth in wireless communication.
- Optimized pilot design can maintain demodulation performance with fewer pilots.
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