상세정보
학술지
Delta-sigma-modulated IFoF Transmission System Assisted by a Correlative-level Encoding Technique
- 발행일
- 201811
- 출처
- Optics Express, v.26 no.23, pp.1-15
- ISSN
- 1094-4087
- 출판사
- Optical Society of America(OSA)
- 협약과제
- 18HF1500, 5G 이동통신용 밀리미터파(40GHz 이하) 빔포밍 부품 개발, 김광선
- 초록
- A delta-sigma-modulated intermediate-frequency-over-fiber (IFoF) transmission system assisted by a correlative-level coding technique is proposed and experimentally demonstrated. Unlike conventional delta-sigma IFoF systems with multiple output levels to achieve higher signal quality or larger capacity, a correlative-level encoder is exploited as a second modulator preceded by the delta-sigma modulator. The encoder compresses the bandwidth of the delta-sigma modulated signal by creating a correlation between adjacent signal symbols. As a result, the sampling frequency of the delta-sigma modulator in the proposed system can be increased beyond the transmission bandwidth of the IFoF system, considerably improving the in-band signal quality and the transmission capacity over the conventional multi-level approach. This is because the quantization noise from the delta-sigma modulation in the proposed scheme is more aggressively pushed away from the signal bandwidth with the high sampling frequency. According to experimental results, the proposed link provides at least a 40% larger transmission capacity for similar in-band signal quality or 2.1% better average EVM performance for the same capacity than the conventional four-level pulse-amplitude-modulation delta-sigma IFoF systems.
- KSP 제안 키워드
- Amplitude Modulation, Delta-Sigma Modulation, Delta-Sigma Modulator, Encoding Technique, Level coding, Modulated signal, Multi-level, Quantization Noise, Sampling frequency, Signal quality, Transmission Capacity