Considerations on the Use of Digital Signal Processing in Future Optical Access Networks

32dB of Optical Budget with DSP-free real time experimentation up to 50Gbit/s NRZ using O-band DFB-EAM and SOA-PIN for Higher Speed PONs

“…Reaching this target was not possible using simple and low cost optics without introducing Digital Signal Processing (DSP) [5,6]. However, using DSP in PONs will considerably increase the cost and complexity (cost of complex equalizers, added power consumption, Transmission Dispersion Eye Closure (TDEC) management) for physical layer interoperability in HSP [7,8]. It would also increase the processing and burst timing issues that should be avoided to maintain the maximum effective throughput and lowest latency.…”

Experimental Study on 25 Gbps C-Band PON over up to 25 km SMF Using a 10G-Class DML + APD IM-DD System

“…Our group has analyzed in previous papers the performance of directly modulated laser (DML)-based IM-DD PON systems in O-band [9][10][11]. In [12,13], the channel frequency response of a DML-based IM-DD system was investigated in O-band through simulations and theoretical calculations. In general, DML represents a good choice when it operates in a system with low chromatic dispersion (CD), for example, in O-band, because of the low cost and small footprint advantages [14][15][16], while, because of laser chirp effects, it is usually less suitable for C-band operation.…”

Simplified SVM Equalization Algorithm Based on Single Hyperplane Training Enabled 50Gb/s PAM-4/8 With 10-G Optics in NG-PON System

“…To resolve this problem mentioned above, some equalization schemes [9][10][11][12][13][14][15][16][17][18][19] based on digital signal processing (DSP) technology have been presented in high-speed limitedbandwidth NG-PON system. Owing to its simple implementation, strong adaptability, and significant performance improvement [14], the equalization schemes have become the mainstream ISI compensation methods.…”

“…Owing to its simple implementation, strong adaptability, and significant performance improvement [14], the equalization schemes have become the mainstream ISI compensation methods. Among these proposed researches, the commonly used are the feedforward equalizer (FFE) [15], decision feedback equalizer (DFE) [19], and Volterra filter [13], whose tap coefficients are updated through adaptive algorithms such as the least mean square (LMS) algorithm and the gradient least squares (RLS) algorithm [17]. Despite that, these common equalizers have unsatisfactory performances in severely distorted channel transmission systems.…”