- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Decoding of 10-G Optics-Based 50-Gb/s PAM-4 Signal Using Simplified MLSE
摘要： A simpli?ed maximum likelihood sequence estimation (MLSE) based on Viterbi algorithm has been proposed. Experimental results show that compared with the conventional MLSE, the proposed algorithm saves the multiplication by 25% with no sensitivity penalty when the memory length of MLSE is 2 both in the 25 Gb/s nonreturn to zero and 50 Gb/s four-level pulse-amplitude modulation (PAM-4) transmission systems. In order to further reduce the number of multiplications in the 50 Gb/s PAM-4 transmission system, we use 75 taps of feed-forward equalization to equalize the received PAM-4 signal into duo-binary PAM-4 (DB-PAM-4) signal and then use MLSE with the memory length of 1 to decode, which improves the sensitivity performance by 1.8 dB and reduces the computing complexity by ～98% compared with conventional MLSE (L = 4) method. As a result, a 10-km C-band transmission of 50 Gb/s PAM-4 signal is achieved using optical transceivers with a combined 3-dB bandwidth of ～8 GHz, and only 107 multiplications are required by using our proposed simpli?ed algorithm for equalization.
关键词： feed-forward equalization (FFE),four-level pulse-amplitude modulation (PAM-4),Viterbi algorithm,Maximum likelihood sequence estimation (MLSE)
更新于2025-09-23 15:21:01
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Four-PAM Modulation of Ambient FM Backscattering for Spectrally Efficient Low-Power Applications
摘要： Ambient backscatter uses radio frequency signals available in the environment (e.g., radio broadcasting, television, or mobile telephony) to transmit data effectively leading to significant energy and cost efficiency increase. This paper presents a novel wireless tag, which for the first time utilizes 4-pulse amplitude modulation technique to modulate the ambient backscattered FM signals in order to send data to a nearby low-cost software defined radio reader. The tag is based on an RF front-end that uses a single transistor controlled by an ultralow-power microcontroller. The microcontroller includes an analog-to-digital converter for sensing and a digital-to-analog converter for RF front-end control. A proof-of-concept prototype is demonstrated in an indoor environment with the low bit rate of 345 b/s and power consumption 27 μW. It operated using a real FM station at 34.5 km away and the tag-to-reader distance was tested at 1 m. The value of energy spent in this modulator was 78.2 nJ/bit at 345 b/s and 27.7 nJ/bit at 10.2 kb/s.
关键词： Internet-of-Things (IoT),backscatter communication,Ambient backscattering,software-defined radio (SDR),pulse amplitude modulation (PAM),FM modulation,radio frequency identification (RFID) sensors
更新于2025-09-10 09:29:36
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[IEEE 2018 IEEE Photonics Conference (IPC) - Reston, VA, USA (2018.9.30-2018.10.4)] 2018 IEEE Photonics Conference (IPC) - 10-Gb/s Transmission Over 10-m SI-POF with M-PAM and Multilayer Perceptron Equalizer
摘要： We demonstrate the gigabit-per-second transmission over a step-index plastic optical fiber (SI-POF) of 10-m length with a pulse-amplitude modulation (PAM). A multilayer perceptron-based equalizer is used to mitigate an intersymbol interference and non-linearity in the system. Using this equalizer with 32-PAM, a data rate of 10 Gb/s is achieved over the 10-m SI-POF at a bit error rate of 10?2, which is below the 20% forward error correction limit.
关键词： multilayer perceptron (MLP),Polymer optical fiber (POF),pulse amplitude modulation (PAM),decision feedback equalizer,non-linearity
更新于2025-09-04 15:30:14