11 × 5 × 93Gb/s WDM-CAP-PON based on optical single-side band multi-level multi-band carrier-less amplitude and phase modulation with direct detection

Abstract

We propose and demonstrate a novel WDM-CAP-PON based on optical single-side band (OSSB) multi-level multi-band carrier-less amplitude and phase modulation (MM-CAP). To enable high-speed transmission with simplified optical network unit (ONU)-side digital signal processing, 4-level 5 sub-bands CAP-16 is used here, which is generated by the digital to analogue converter (DAC). Optical single-side band (OSSB) technology is applied to extend the transmission distance against the spectrum fading effect. As a proof of concept, the experiment successfully demonstrates 11 WDM channels, 55 sub-bands, for 55 users with 9.3-Gb/s per user (after removing 7% overhead for forward error correction (FEC)) in the downstream over 40-km SMF.

Multi-band CAP for Next-Generation Optical Access Networks Using 10-G Optics

“…On the contrary, multi-carrier [15,16] and/or multi-band schemes [17,18] featuring enhanced spectral efficiency and flexibility by fully leveraging advanced digital signal process (DSP) can support high capacity and long reach without altering the optical infrastructure. In addition, simple asymmetrical optical filtering by utilizing the deployed wavelength division multiplexing (WDM) multiplexers (MUXs) and de-multiplexers (De-MUXs) or Arrayed waveguide gratings (AWGs) is advantageous for multi-band or multi-carrier systems to increase fiber dispersion tolerance [16][17][18]. As indicated in [7], such optical filtering approach can achieve stable performance in field trial demonstrations.…”

“…High speed single-or multi-band carrierless amplitude and phase (CAP) modulation systems have been intensively investigated for a potential low cost solutions for medium and long reach PONs [18][19][20][21]. Nevertheless, none of these demonstrations except [19] [22].…”

“…Nevertheless, none of these demonstrations except [19] [22]. Although training symbols-assisted phase tracking and estimation in the receiver side can recover the signal [18,21], it introduces overhead and additionally high frequency non-data dependent jitter beyond the phase tacking loop bandwidth cannot be tracked or compensated. We have proposed partial differential quadrature amplitude modulation (QAM) encoding and decoding schemes together with multi-modulus algorithm (MMA) equalization to efficiently recover multi-band CAP signals in a completely blind manner [17,19].…”

“…The OBPF has a filtering profile very similar to a 50-GHz grid WDM MUX [23]. The OBPF is tuned to generate a frequency offset between the laser frequency and the MUX center frequency, leading to a VSB multi-band CAP signal [17][18][19]. The VSB signal can significantly increase the tolerance to fiber CD compared to the double sideband (DSB) case.…”

A Multi-CAP Visible-Light Communications System With 4.85-b/s/Hz Spectral Efficiency

“…The impulse responses of the transmit filters are given by [17]: and overall in-phase filter impulse response (blue) for the first subcarrier of an m-CAP system; (bottom) shows the sine carrier (black), SRRC impulse (red) and quadrature filter impulse (green) for the same subcarrier for the in-phase filter and the following for the quadrature filter, where T s is the symbol duration and ξ = π t Ts [17]:…”