In the proposed system, an rf tone is inserted at the edge subcarrier of the ofdm signal to assist remote signal extraction after beating with all ofdm subcarriers at the receiver. Comparison of direct and heterodyne detection optical. Home forums system coherent detection ofdm coherent detection ofdm chee joined november 2014 participant i want to simulate an ofdm coherent detection system. Kahn stanford university, 366 packard building, 350 serra mall, stanford, ca 943059515, usa. The impact of dc bias and the rf drive voltage of the dual electrode mach zehnder modulator demzm on the transmission performance of optical orthogonal frequency division multiplexing o ofdm direct detected systems is analyzed theoretically and verified by simulation. Evaluation of the computational effort for chromatic dispersion compensation in coherent optical pm ofdm and pmqam systems p. Optical links can be implemented using either direct or heterodyne detection receivers 1si. Pdf investigation of pmd in directdetection optical ofdm with. We first study the conventional equalization method for zpofdm. This work proposes a novel directdetection polarization division multiplexed ofdm scheme without the need of dynamic polarization control at a polarizationdiverse receiver, and the proposed scheme is robust against polarization mode dispersion. Direct detected optical ofdm ddo ofdm has been demonstrated to have 21ps differential group delay dgd tolerance for a 10gbits total line rate with numerical simulations 11, which could be enhanced by polarization diversity with combined cd and pmd compensation at the receiver 12.
Pmd tolerant directdetection polarization division multiplexed ofdm systems with mimo processing. Performance analysis of direct detection and coherent. Directdetection optical ofdm ddoofdm is a promising candidate for shorthaul links such as access networks, data centers and broadband wireless topologies, mainly due to its simplicity at the optical receiver architecture as it can use the same optical components employed in onoffkeying ook systems. Jun 14, 2015 this paper investigates the transmission of an injectionlocked optical orthogonal frequencydivision multiplexing ilo ofdm scheme over an optical fiber. Finisar is a global technology leader in optical communication subsystems and components that enable highspeed voice, video and data communications for networking, storage, wireless, and cable tv applications. Pmd tolerant directdetection polarization division multiplexed ofdm systems with mimo processing article in optics express 207. Performance analysis of direct detection and coherent detection system for optical ofdm using qam. Advanced digital signal processing techniques for high. The following performance criteria of optical detectors are of major important for applications in optical communication. Clipping noise mitigation in optical ofdm systems cuiwei he and jean armstrong abstractthis letter describes a new nonlinear algorithm for clipping noise mitigation in intensity modulationdirect detection dc biased optical orthogonal frequency division multiplexing dcoofdm systems. Coherent detection in optical fiber systems ezra ip, alan pak tao lau, daniel j.
Gb on an amdd, 4qam, 10gbps system and 10km of fiber. In conclusion, opm from the state model of mlse equalizers in direct detection systems is elaborate and only allows for limited access to individual channel parameters. Shieh, pmdsupported coherent optical ofdm systems, ieee photon. Precoding based peaktoaverage power ratio reduction for. Investigation of pmd in directdetection optical ofdm with. Theoretical and experimental study on pmdsupported. Sep 09, 20 investigation of pmd in directdetection optical ofdm with zero padding.
Enabling high capacity directdetection optical ofdm. Pdf implementation of optical ofdm based system for optical. Several key technologies in ddoofdm system have been discussed. Joint compensation of cd and pmd in directdetected ofdm.
Schmidt, arthur james lowery, and jean armstrong, impact of pmd in singlereceiver and polarizationdiverse directdetection optical ofdm, j. International journal of scientific and research publications, volume 4, issue 1, january 2014 keywords. Pmd tolerance of 288 gbits coherent wdm and transmission. Joint compensation of cd and pmd in direct detected ofdm. Pmd tolerant directdetection polarization division. This could cause a majority of the subcarriers to fade in power. Osa pmd tolerant directdetection polarization division multiplexed. Cd tolerance compared to the previous intensitymodulated singlesideband. Pdf investigation of pmd in directdetection optical ofdm. Coherent detection can provide a potential improvement up to 20 db in the receiver sensivity unlike direct detection based systems for a given power budget, this would allow to increase the total length of an optical link or spacing between repeatersaplifiers.
Although there is a systematic separation of deterministic signal components and noisy distortions, the identification of individual deterministic distortions like cd or pmd is not possible, nor is the identification of different noise sources. Impact of nonlinearities on optical ofdm with direct detection. Pmd, pmd measurement, pmd tolerance, pmd testbed, polarization synthesizer, insitu pmd 1. Clipping noise is often the major limitation in dcoofdm. Then an equalization method based on sorted qr decomposition is proposed to further improve the performance.
A comprehensive theoretical model of direct detection dd optical orthogonal frequency division multiplexing oofdm system is described in general. Impact of nonlinearities on optical ofdm with direct detection abdulamir ali, jochen leibrich, werner rosenkranz chair for communications, university of kiel, kaiserstrasse 2, 24143 kiel, germany, email. Fiber dispersion effects in injectionlocked optical ofdm systems. Direct detection system an overview sciencedirect topics.
Setting the frequency difference between two polarizationorthogonal reference carriers as one subcarrier spacing, possible signal fading can be. The first part of the thesis is devoted to directdetection systems, with a spe cific focus on. In imdd, orthogonal frequency division multiplexing ofdm, originally employed in radio frequency communication, is considered as a strong candidate solution to. The efficiency of precoding is investigated on a recently discussed approach for optical ofdm, capable of direct detection based on compatible singlesideband modulation compssb 8,9. Haunstein 2007 pmd tolerant directdetection optical. Osa pmd tolerant directdetection polarization division. Layered acoofdm for intensitymodulated directdetection optical wireless transmission qi wang,1 chen qian,1 xuhan guo,2 zhaocheng wang,1.
We investigate the polarization mode dispersion pmd effect of zero padding ofdm zpofdm in directdetection optical orthogonal frequency division multiplexing ddoofdm systems. Spectrally efficient polarization multiplexed directdetection ofdm system without frequency gap. A 4 qam coherent optical ofdm system was simulated with 8192 samples at 50 gbps. Optical orthogonal frequency division systems with direct. Ofdm for fiberoptic data transmission at high spectral. Direct detection of exoplanets direct detection producing an actual image of the object, not indirect detection through its influence on its parent star. Conclusion in this paper, we presented an opticalofdm system design model for both single mode and multimode fiber. In the ilo ofdm system, an optically injectionlocked semiconductor laser is utilized to directly modulate the ofdm signal on the optical carrier.
Nongaussian statistics of coofdm signals after nonlinear optical fibre. The limit of distance varies from single mode to multimode fiber. Experimental validation of a constantenvelope ofdm system. Forghieri2 1 dipartimento di elettronica, politecnico di torino, corso duca degli abruzzi, 24 10129 torino, italy. Index termsdirect detection, optical fiber communication, optical modulation. Abstract the impact of kerr effect and modulator nonlinearity on optical ofdm transmission is studied for an. Chiachien wei,1, chunting lin,2 and chihyun wang2 1 department of photonics, national sun yatsen university, kaohsiung, taiwan. Joint compensation of cd and pmd in direct detected ofdm transmission using polarizationtime coding weiren peng 1, kaiming feng 2, and sien chi 1 1department of photonics and institute of electro optical engineering, national chiao tung university, hsinchu. Layered acoofdm for intensitymodulated directdetection. Pmd tolerant direct detection polarization division multiplexed ofdm systems with mimo processing chiachien wei,1, chunting lin,2 and chihyun wang2 1 department of photonics, national sun yatsen university, kaohsiung, taiwan. Polarizationmode dispersion pmd can cause frequencyselective fading in directdetection optical orthogonal frequency division multiplexing ddoofdm systems. The possibility of polarizationmode dispersion pmd compensation in fiberoptic communication systems with direct detection using a simple channel estimation technique and lowdensity paritycheck ldpccoded orthogonal frequency division multiplexing ofdm is demonstrated.
Xie, pmd insensitive directdetection optical ofdm systems using selfpolarization diversity, in optical fiber communication conference and exposition and the national fiber optic engineers conference. Coherent optical ofdm using 64qam to high data rates 1. In a direct detection optical ofdm system, where the carrier is displaced away from the subcarriers, the carrier and subcarriers may suffer different polarization rotations, so the carrier will no longer mix with the subcarriers at the photodiode. Evaluation of the computational effort for chromatic. Optical ofdm has recently attracted lots of interest because of its simple equalizer for compensating the linear impairments throughout the link1,2. Pmd compensation in fiberoptic communication systems with direct detection using ldpccoded ofdm article in optics express 157. However, because a single larger ofdm band per wavelength was used, such. Investigation of pmd in directdetection optical ofdm with zero padding article pdf available in optics express 2118. In this method an optical carrier is transmitted whose relative. Digital optical systems based on coherent and direct detection.
Pmd compensation in fiberoptic communication systems with direct detection using. Xie, pmd insensitive directdetection optical ofdm systems using selfpolarization diversity, in optical fiber communication conference and exposition and the national fiber optic engineers conference, osa technical digest cd optical society of america, 2008, paper omm2. Theoretical and experimental investigations of directdetected rf. Ofdm system can be mainly categorized as 1 coherent and. Aug 06, 2007 theoretical and experimental study on pmd supported transmission using polarization diversity in coherent optical ofdm systems. Numerical simulation results show that compared with cyclic prefix ofdm cpofdm, zpofdm has a significantly higher tolerance to pmd in ddoofdm systems when the channel spectral nulls occur at certain differential group delay dgd values. Frequency interleaving towards spectrally efficient directly. Compared with the coherent optical ofdm co ofdm 1, the lowerpriced and lesscomplex direct detection optical ofdm ddo ofdm 2 would be a more suitable candidate for.
Intensity modulation and direct detection imdd is a costeffective optical communication strategy which finds wide applications in fiber communication, freespace optical communication, and indoor visible light communication. As long as there is no pmd or pdl the two orthogonally polarized. Coherent optical orthogonal frequency division multiplexing coofdm is highly tolerant against. In 3, the performances of three singlereceiver ddofdm formats at 42. With a sufficiently large injection strength and a negative shift of the detuning frequency. Precise analysis of optical ofdm system in direct and diffused optical wireless environment mohamed e. In this paper, we conduct theoretical and experimental study on the pmd supported transmission with coherent optical orthogonal frequencydivision multiplexing co ofdm.
The application of ofdm in optical fiber communication systems. White2 1tsinghua national laboratory for information science and technology tnlist,department of electronic engineering, tsinghua university, beijing 84, china. The possibility of polarization mode dispersion pmd compensation in fiberoptic communication systems with direct detection. Design and performance analysisof ofdmbased single mode and. Precise analysis of optical ofdm system in direct and. Pdf performance analysis of direct detection and coherent. Optical orthogonal division multiplexing for long haul. Finisar provides system manufacturers with critical breakthroughs in optics technologies, and the production volumes. Theoretical and experimental study on pmd supported. Tamazin college of engineering and technology, arab academy for science, technology and maritime transport, alexandria, egypt.
Osa investigation of pmd in directdetection optical ofdm. Non gaussian statistics of coofdm signals after nonlinear optical fibre. Implementation of optical ofdm based system for optical networks article pdf available in international journal of electrical and computer engineering vol. Performance evaluation of optical ofdm in direct detected. In a direct detection receiver 3, the received optical intensity is detected without extensive frontend optical processing. This approach applies the signal to the amplitude of the transmitted ssbsignal 10. Key technologies for optical ofdm in optical longhaul system.