Beat-Noise-Free OCDM Technique Employing Spectral M-ary ASK Based on Electrical-Domain Spatial Code Spreading

Demonstration of 1 Gb/s$\,\times \,$15-User CDM Over WDM-PON Using Electrical Spatial Coding and Subcarrier Multiplexing

“…Electrically processed OCDMA systems, or code division multiplexing (CDM) over fiber systems based on charge-coupled devices (CCDs) [5] processing at chip rate is used in those systems, the electrical processing speed poses a bottleneck, limiting the data rate and the number of access users. Shin Kaneko, et al [7] proposed a CDM over fiber system based on electrical spatial coding to avoid chip-rate processing and therefore can achieve a data rate of 1.5 Gb/s. However, the number of optical devices used in this scheme increases linearly with the code length, which may lead to high cost when long codes are used.…”

Impact of ADC Bandwidth and Clipping Ratio on COF-PON Systems Based on Spatial Coding and Subcarrier Multiplexing

“…Additionally, expensive devices such as ultra-short pulse lasers, optical thresholders and optical time gating devices are also needed, increasing the overall cost. Fortunately, by using CDM over fiber technology, i.e., by coding and multiplexing electronically and then up converted to optical domain, MAI can be eliminated effectively [5] and can therefore increase the number of access users as well as reducing system cost.…”

“…2) By using electrical en/decoding, MAI can be eliminated effectively, and therefore no optical thresholders and optical time gating devices are needed. 3) Subcarrier multiplexing increases the spectrum efficiency and avoids massive usage of optical components, as compared with [5]. More importantly, using both spatial coding and subcarrier multiplexing offers us coding gain when the number of simultaneous users is smaller than the number of subcarriers (code length) [6].…”

Electrically Processed OCDMA System Based on Spatial Coding and Subcarrier Multiplexing

“…Electrically processed OCDMA systems using CCDs [6], FIR filters [5], etc as chip-rate en/decoders have been proposed recently [5]- [7]. These chip-rate en/decoders are very difficult to achieve high speed or long code lengths due to their limited processing speed.…”

“…These chip-rate en/decoders are very difficult to achieve high speed or long code lengths due to their limited processing speed. Another work by Shin Kaneko, et al [7], used a spectral M-ary ASK technique based on electrical-domain spatial code spreading to perform data-rate processing. In that scheme, each tributary data steam generated by the spatial encoder is modulated separately using an external modulator with an LD of different emitting frequency.…”