Multiband Carrierless Amplitude Phase Modulation for High Capacity Optical Data Links

Abstract

Short range optical data links are experiencing bandwidth limitations making it very challenging to cope with the growing data transmission capacity demands. Parallel optics appears as a valid short-term solution. It is, however, not a viable solution in the long-term because of its complex optical packaging. Therefore, increasing effort is now put into the possibility of exploiting higher order modulation formats with increased spectral efficiency and reduced optical transceiver complexity. As these type of links are based on intensity modulation and direct detection, modulation formats relying on optical coherent detection can not be straight forwardly employed. As an alternative and more viable solution, this paper proposes the use of carrierless amplitude phase (CAP) in a novel multiband approach (MultiCAP) that achieves record spectral efficiency, increases tolerance towards dispersion and bandwidth limitations, and reduces the complexity of the transceiver. We report on numerical simulations and experimental demonstrations with capacity beyond 100 Gb/s transmission using a single externally modulated laser. In addition, an extensive comparison with conventional CAP is also provided. The reported experiment uses MultiCAP to achieve 102.4 Gb/s transmission, corresponding to a data payload of 95.2 Gb/s error free transmission by using a 7% forward error correction code. The signal is successfully recovered after 15 km of standard single mode fiber in a system limited by a 3 dB bandwidth of 14 GHz.

A Carrierless Amplitude Phase (CAP) Modulation Format: Perspective and Prospect in Optical Transmission System

“…In order to extend the bandwidth of each channel for high speed data transmission, multi-level multi-band CAP (MultiCAP) or m-CAP modulation format (where m is the number of subcarriers or subbands) has been introduced by dividing the CAP signal into smaller sub-bands [19], [20]. The use of carrierless amplitude phase (CAP) in a novel multiband approach (MultiCAP) for high capacity optical data links manage to extend the system capacity to 102.4 Gb/s over 15 km of SSMF.…”

Visible Light Communications towards 5G

“…A possible solution for this was introduced in [33], where the available bandwidth is divided into a multiband (m-CAP) format for an optical fiber channel. The transmission bandwidth was split into 6 sub-bands (subcarriers) and the performance was compared with the traditional CAP (1-CAP) system.…”

Design and Analysis of a Novel FSO Transmission Scheme Using Pulse Amplitude Modulation

“…This model considers light intensity is composed of the multiplication which can accurately describe the fluctuation characteristics of the received light intensity in the case of strong turbulence. Since the Gamma-Gamma model takes into account the influence of turbulence at each scale, this model can apply weak turbulence area to strong turbulence area [4][5][6][7][8].…”