Polarization Division Multiplexing Transmission Research Articles

3 × 3 MIMO Fiber–Wireless System in W-Band With WDM/PDM RoF Transmission Capability

We propose and demonstrate a 3 × 3 full multiple-input multiple-output (MIMO) fiber–wireless system in the W-band with wavelength-division multiplexing (WDM) and polarization-division multiplexing (PDM) radio-over-fiber (RoF) transmission capability. The system is realized using two highly stable RoF links based on the optical self-heterodyne method and PDM transmission in one of the RoF links. We experimentally demonstrate and confirm satisfactory performances for a 3 × 3 MIMO offset quadrature amplitude modulation-based filter-bank multicarrier signal. Total capacities of approximately 110 and 132 Gb/s, corresponding to spectral efficiencies of approximately 8.5 and 10.2 bits/s/Hz, respectively, are achieved for the system using antennas placed in the same and alternately different polarizations, respectively. The system is applicable to WDM and combined WDM/PDM RoF transmissions. It provides a scalable solution for facilitating large-scale MIMO signal transportation and can be a promising solution for future mobile transport and radio access networks in high-frequency bands.

Meeting the future metro network challenges and requirements by adopting programmable S-BVT with direct-detection and PDM functionality

Abstract In this paper, we propose an advanced programmable sliceable-bandwidth variable transceiver (S-BVT) with polarization division multiplexing (PDM) capability as a key enabler to fulfill the requirements for future 5G networks. Thanks to its cost-effective optoelectronic front-end based on orthogonal frequency division multiplexing (OFDM) technology and direct-detection (DD), the proposed S-BVT becomes suitable for next generation highly flexible and scalable metro networks. Polarization beam splitters (PBSs) and controllers (PCs), available on-demand, are included at the transceivers and at the network nodes, further enhancing the system flexibility and promoting an efficient use of the spectrum. 40G–100G PDM transmission has been experimentally demonstrated, within a 4-node photonic mesh network (ADRENALINE testbed), implementing a simplified equalization process.

Asymmetric multi-input multi-output system in visible light communication for polarization-tolerant polarization division multiplexing transmission

We propose an asymmetric 3×2 multi-input multi-output (MIMO) system for polarization division multiplexing (PDM) transmission in visible light communication (VLC). In PDM transmission, independent channels are constructed by polarization orthogonality, which is vulnerable to misalignment of polarization between the transmitter and the receiver. Although PDM-based VLC system may not maintain polarization orthogonality, the proposed asymmetric MIMO system can achieve the polarization diversity required for a multichannel system. We experimentally demonstrate the performance enhancement of PDM VLC transmission using the proposed asymmetric 3×2 MIMO technique.

Polarization Division Multiplexing of OFDM Radio-over-Fiber Signals in Passive Optical Networks

This paper describes the state-of-the-art of polarization multiplexing for optical networks transmission. The use of polarization division multiplexing (PDM) permits to multiply the user capacity and increase the spectral efficiency. Combining PDM and orthogonal frequency division multiplexed (OFDM) modulation allows maximizing the optical transmission capacity. The experimental demonstration of transmitting OFDM signals following ECMA-368 ultrawide band (UWB) standard in radio-over-fiber using PDM in passive optical networks is herein reported. The impact of cross-polarization and cochannel crosstalk is evaluated experimentally in a three-user OFDM-UWB subcarrier multiplexed (SCM) configuration per polarization. Each SCM uses up to three OFDM-UWB channels of 200 Mbit/s each, achieving an aggregated bitrate of 1.2 Gbit/s with 0.76 bit/s/Hz spectral efficiency when using PDM transmission. The experimental results for the polarization-multiplexed SCM indicate that a 4 dB additional polarization crosstalk interference can be expected compared to a nonpolarization-multiplexed transmission system which translates to 2.4 dB EVM penalty in the UWB signals. The successful PDM transmission of SCM multiuser OFDM-UWB over a passive optical network of 25 km standard-single mode fiber (SSMF) reach is demonstrated.

Polarization pulling and signal amplification using Raman scattering for Polarization Division Multiplexing transmission system

Polarization pulling and signal amplification using Raman scattering for Polarization Division Multiplexing transmission system

Cross-Polarization Modulation in Polarization-Division Multiplex Transmission

We show theoretically and with the aid of computer simulations that the nonlinear depolarization induced by cross-polarization modulation leads to crosstalk between the polarization-division multiplex (PolDM) subchannels during their demultiplexing. This additive crosstalk can be approximated as additive Gaussian noise, and we derive expressions to estimate its variance. It can lead to significant penalties of up to several decibels for PolDM transmission and must be properly accounted for. We also show why time-interleaving both subchannels can significantly reduce these penalties.

Statistical Polarization Mode Dispersion/Polarization Dependent Loss Emulator for Polarization Division Multiplexing Transmission Testing

A low-cost statistical polarization mode dispersion/polarization dependent loss emulator is presented in this article. The emulator was constructed by concatenating 15 highly birefringence optical-fiber segments and randomly varying the mode coupling between them by rotating the polarization state. The impact of polarization effects on polarization division multiplexing transmission quality was measured. The designed polarization mode dispersion/polarization dependent loss emulator was applied to mimic the polarization effects of real optical-fiber links.

1.6-b/s/Hz 160-Gb/s 230-km RZ-DQPSK polarization multiplex transmission with tunable dispersion compensation

A 160-Gb/s (4/spl times/40 Gb/s) return-to-zero differential quadrature phase-shift keying polarization-division multiplex transmission is demonstrated with Q>15.6 dB in one of eight 100-GHz-spaced wavelength-division-multiplex channels after 230 km of fiber. Residual chromatic dispersion (CD) is equalized by a thermally tunable CD compensator for the 192.5-THz channel. Polarizations, in-phase and quadrature data channels are demultiplexed using a LiNbO/sub 3/-based automatic polarization control and a 1-bit interferometer, respectively.

Polarization mode dispersion detected by arrival time measurement of polarization-scrambled light

Polarization mode dispersion (PMD) limits optical fiber capacity. PMD compensators usually minimize the associated eye closure. This measure scales with the square of the differential group delay (DGD) and makes it difficult to detect low DGDs. However, light with a low-speed polarization modulation suffers arrival time variations, in the presence of PMD, that are proportional to the DGD. These are detected by integrating the voltage-controlled oscillator (VCO) input signal of the clock recovery phase-locked loop (PLL). This novel method has been demonstrated for 40 Gb/s nonreturn-to-zero (NRZ) and for 2/spl times/40 Gb/s return-to-zero (RZ) polarization division multiplex transmission. PMD detection sensitivities range between 2 ps and 84 fs.

Tolerance of bandwidth-efficient optical multilevel modulation schemes against polarization mode dispersion

Optical polarization division multiplex transmission shows a superior sensitivity and a good polarization mode dispersion tolerance compared to other multilevel modulation schemes. Due to its terminal equipment simplicity compared to quaternary intensity modulation this scheme is advantageous for capacity doubling of fiber spans with a given amplification bandwidth. Theory is verified in a 2 × 10 Gbit/s polarization division multiplex transmission system.

Crosstalk detection schemes for polarization division multiplex transmission

Polarization division multiplex (PolDM) is a bandwidth-efficient and sensitive modulation format suitable for upgrading bandwidth-limited trunk lines. We show how control signals for polarization demultiplex can be obtained efficiently. For interleaved return-to-zero (RZ) signals, incoherent crosstalk has to be detected and minimized. In other cases, in particular for non-return-to-zero (NRZ) signals, coherent crosstalk senses penalties much better and should be detected instead. NRZ transmission experiments with either scheme are presented at a data rate of 2/spl times/10 Gb/s, with endless polarization tracking. Polarization mode dispersion (PMD) tolerance is also assessed.

Multiple soliton interactions in a polarization–division multiplexing system

We numerically study multiple soliton interactions in a polarization–division multiplexing transmission system. It is found that, unlike the transmission system of solitons with the same polarization, the two soliton interaction is not the strongest compared to the interaction of more than two solitons. Therefore, the maximum transmission distance limited by the interaction of solitons cannot be inferred by the collision distance of two solitons in a polarization–division multiplexing system and the interactions of more solitons must be considered.

Modified propagation equations for soliton transmission in a polarization-division multiplexing system

The modified coupled averaged propagation equations describing the orthogonally polarized soliton propagation in a random birefringent fibre are derived. These include the third-order dispersion and Raman shift terms. Using these equations, the effects of the third-order dispersion and Raman shift terms are found to reduce the soliton interactions in a polarization-division multiplexing transmission system.