Low-Complexity Chromatic Dispersion Equalizer for 400G Transmission Systems

Abstract

We experimentally demonstrate a reduced complexity time-domain CD equalizer in a dual-carrier 400G PM-16QAM system, yielding hardware savings of over 99% in terms of multipliers, and a latency reduction of ∼80% over standard frequency-domain CD equalization.

Real-time demonstration of low-complexity time-domain chromatic dispersion equalization

“…In contrast, the number of logic units required by the standard FIR-CDE has been found to largely surpass the available resources, thus preventing its real-time implementation in the considered FPGA platform. In accordance with the complexity analysis provided in the previous work [4,6], these results demonstrate that the MD-FIR-CDE allows for an highly efficient FPGA implementation, also indicating that its usage on an application specific integrated circuit (ASIC) can result in significant gains both in terms of chip area and power consumption.…”

“…Following our previous work [4,6], where the experimental demonstration with offline data was presented, in this work we provide a real-time validation of the MD-FIR-CDE using commercially available analog-to-digital converters (ADCs) (4DSP FMC125) and an FPGA platform (Xilinx Virtex-6 FPGA). Due to the hardware limitations in terms of electrical bandwidth and sampling/processing rate, the real-time experiment is carried out for a single-channel 2.5 Gb/s QPSK optical signal.…”

“…Nevertheless, TD FIR-based equalizer is attractive for its ease of implementation, since it avoids the use of block processing from fast-fourier transform (FFT) and inverse fastfourier transform (IFFT), thus facilitating real-time applications. Several research works have been performed to reduce the complexity of TD FIR-based equalizer [4][5][6]. In our previous work [4], we have proposed a reduced complexity distributive FIR-CDE (D-FIR-CDE) algorithm, which revealed significant complexity and latency gains in comparison with FD and standard TD FIR-based equalizers.…”

“…In our previous work [4], we have proposed a reduced complexity distributive FIR-CDE (D-FIR-CDE) algorithm, which revealed significant complexity and latency gains in comparison with FD and standard TD FIR-based equalizers. In [6] we have performed the experimental validation of the D-FIR-CDE technique in dual-carrier 400G PM-16QAM transmission systems. In addition, we have proposed a multiplierless D-FIR-CDE (MD-FIR-CDE) version as an efficient hardware implementation of D-FIR-CDE [4].…”