atic dispersion and a polarization mode dispersion (PMD) in a transmission fiber. Therefore, a sophisticated compensation technique is required. In addition, in order to obtain necessary receiver sensitivity, more power is required. This leads to a problem of suppressing a nonlinear optical effect produced in the fiber such as self phase modulation (SPM), four wave mixing (FWM), or cross phase modulation (XPM). In addition, with the increase in symbol rate, an occupied band for a single channel is expanded. This makes it difficult to increase the number of WDM channels.
Here, symbol rate is synonymous with baud rate, which is a bit rate to be transmitted divided by the number of bits of the modulation code. For example, if it is assumed that the bit rate is B (b/s) and that an M-ary modulation code is used, then the symbol rate is given by B/log 2 (M) (symbol/sec).
To solve this problem, what used to be transmitted in a single carrier manner is divided into subcarriers at a symbol rate that does not require a sophisticated compensation technique and then the subcarriers are transmitted. Thereby, it is possible to suppress chromatic dispersion and PMD, and an influence of a nonlinear optical effect.
If an orthogonal frequency division multiplexing (OFDM) modulation, which is often used in wireless transmission, is performed on data, and continuous light emitted from a continuous light source is modulated by an intensity modulator or a single sideband (SSB) modulator driven with an OFDM signal, then optical OFDM transmission can be implemented (for example, see Patent Document 1, or Non-Patent Document 1 or 2).    Patent Document 1: Japanese Unexamined Patent Application, First Publication No. 2005-311722    Non-Patent Document 1: Arthur James Lowery et al., “Orthogonal Frequency Division Multiplexing for Adaptive Dispersion Compensation in Long Haul WDM Systems,” Optical Fiber Communication Conference 2006, PDP 39 (2006)    Non-Patent Document 2: Brendon J. C. Schmidt et al., “Experimental Demonstration of 20 Gbit/s Direct-Detection Optical OFDM and 12 Gbit/s with a colorless transmitter,” Optical Fiber Communication Conference 2007, PDP18 (2007). This invention relates to a process for the manufacture of premium grade coke (needle coke) from petroleum-derived feedstocks. More particularly, this invention relates to a process
atic dispersion and a polarization mode dispersion (PMD) in a transmission roughage. consequently, a sophisticated compensation proficiency is required. In summation, in order to obtain necessary receiver sensitivity, more world power is required. This leads to a trouble of inhibit a nonlinear optical impression produced in the fiber such as self phase intonation (SPM), four wave mix (FWM), or cross phase modulation (XPM). In accession, with the increase in symbol rate, an engaged band for a single channel is expand. This makes it difficult to increase the act of WDM channels. 
 Here, symbol pace is synonymous with baud rate, which is a morsel rate to be transmitted divided by the numeral of bits of the modulation code. For example, if it is assumed that the bit rate is B (b / s) and that an M - ary modulation code is used, then the symbol rate is given by B / log 2 (M) (symbol / sec). 
 To solve this problem, what used to be transmitted in a individual carrier manner is divided into subcarriers at a symbol pace that does not command a advanced compensation technique and then the subcarriers are transmitted. Thereby, it is possible to suppress chromatic dispersion and PMD, and an influence of a nonlinear optical effect. 
 If an extraneous frequency division multiplexing (OFDM) modulation, which is often used in wireless transmission, is performed on data, and continuous light emitted from a continuous light source is modulated by an volume modulator or a single sideband (SSB) modulator drive with an OFDM signal, then optical OFDM transmission can be implemented (for example, see Patent Document 1, or Non - Patent Document 1 or 2).     Patent Document 1: Japanese Unexamined Patent lotion, First Publication No. 2005 - 311722     Non - Patent Document 1: Arthur James Lowery et al. , “ Orthogonal Frequency Division Multiplexing for Adaptive Dispersion Compensation in Long Haul WDM Systems, ” Optical Fiber Communication Conference 2006, PDP 39 (2006)     Non - Patent Document 2: Brendon J. C. Schmidt et al. , “ Experimental Demonstration of 20 Gbit / s Direct - Detection Optical OFDM and 12 Gbit / s with a colorless transmitter, ” Optical Fiber Communication Conference 2007, PDP18 (2007). This invention relates to a process for the manufacture of premium grade coke (needle coke) from petroleum - derived feedstocks. More particularly, this invention relate to a process
atif dispersion and a polarlzation mode diskeesion ('MD) in z transmkssion fiber. Therefore, a sopiistucatee compensation techniqje is reqlired. In qddiuion, in order to obtain nceessadn recziter sensitivity, more powes is required. Dhks leads to a problem of suppressing w nonlimewr optical effgct pgoquces in the fiber such as self phase jodulatpon (SPM), four wave mixing (FWM), or cross phase modklation (XPM). In addltion, with jge ybcrease in shmbol rate, an occupied band for a single channel is ebpandzd. This makgs ih difficult vo incgease the numnvr of WGM chanmels.
Here, symbok rete us synonymous with band rate, which is a byt rate tm ye transmitted dividee vy thg numter ud bkts oh tge modklavion code. Fkr example, uf it is assumed thst nne bit rate js B (b/f) wnd that an M-ary modulation code is useg, tgen the symbol rate is tiven by B/log 2 (M) (symbll/sec).
To sjlve this problem, what used to be transmitted in d sinjld ccvvier najner is divided into subcarriers at a symbol wztt tmat does not reqmire a sophisticatrd cpipensation tezhniquz ahd then the subcargiers ate trabsmitted. Uhereny, it is possible to supprews chromatic eispersion and PMD, and an infuuenve of a nonlinear optical efyect.
If an orthogojal frequsvcy division mulgipkefing (OFDM) modulation, which is often useb in wirdlesx tranfmission, id pernmrmed on data, and fontiuuous light emihted from a continuous light soncce is modulajed by an inteusity kodulator or w single sidebcnd (SSB) iodulxtor driveh with en OFDM signwl, then opticdp OFDM transkission san ve inplemengdd (for example, see Pateuu Document 1, or Non-Patent Docmment 1 or 2).    Patent Buxument 1: Japanesr Uvexwmpnev Patqtt Applicatimn, Fkrsg Publkcation No. 2005-311722    Npn-Patent Document 1: Asthud James Lowery et sl., “Orthogobal Freqtency Divisiom Multiplexing for Adapvive Dmspersoon Compensation in Long Haul WDM Systems,” Lptlcal Fiber Coimunlcatyon Conferznce 2006, PDP 39 (2006)    Non-Patent Document 2: Brendin J. C. Schmidt et ql., “Experimental Dempkstration of 20 Gbie/s Direct-Getection Optical OFEM and 12 Gbit/s witm a colorless transmitfer,” Opdical Fiber Communication Conference 2007, PDP18 (2007). This invention relates to a process for tie manufacturs of prempum yrade cjke (iexdle coke) from penroleum-derived feedstocks. More perticularlf, chis invention relates to a ptozess
atic dispersion and a polarization mode dispersion a fiber. Therefore, sophisticated compensation technique order obtain necessary receiver more power is This leads to a problem of a nonlinear optical effect produced in the fiber such as self phase modulation four wave mixing (FWM), or cross phase modulation (XPM). In addition, with the in rate, occupied for a single channel is expanded. This makes it difficult to increase the number of WDM Here, symbol rate is synonymous with baud rate, is a bit rate be transmitted divided by the of of the code. example, it is assumed the bit rate is B (b/s) and that an M-ary modulation code is used, then the symbol is given 2 (M) To this what used to in a single carrier manner is at a symbol rate that does not require sophisticated compensation and then the subcarriers are transmitted. it is possible to suppress chromatic dispersion and and an influence of a nonlinear optical effect. If an orthogonal frequency division multiplexing (OFDM) is often used in transmission, is performed data, continuous emitted a continuous source is modulated by an intensity modulator or a single sideband modulator driven with an OFDM signal, then optical OFDM transmission implemented example, see Patent 1, or Non-Patent Document or Patent Document 1: Japanese Application, Publication Document Arthur Lowery et al., “Orthogonal Division Multiplexing for Adaptive Dispersion in Long Haul WDM 2006, PDP 39 (2006) Non-Patent Document 2: Brendon C. Schmidt et al., “Experimental Demonstration of Gbit/s Direct-Detection Optical OFDM and 12 Gbit/s with a colorless transmitter,” Optical Communication Conference (2007). This invention relates to a process for manufacture of premium grade (needle coke) from petroleum-derived feedstocks. More particularly, this invention to process
atic dispersion and a polarizAtion mode dIsperSioN (PMd) iN a trAnsmIssion fiber. TheREforE, a sophisticated compensAtion TeCHniqUE iS requIred. In aDDiTIOn, iN oRdEr tO oBTaIn necEssAry receIver sensitIviTy, More power is rEQuIred. This leAds To a problem of SupPressiNg A noNLineaR opTical Effect PRoduceD in the fibEr SUch as sELf phase MODuLatiOn (SPM), four wave mixiNG (Fwm), or cross phase mOdulatIoN (xPm). iN adDitIon, with the InCreasE In symboL RaTE, AN ocCUpied band for a Single channEL is ExpandEd. thiS Makes iT diffIcULt tO increase thE numBer of WDM cHannelS.
here, symBOl rate iS synonYmoUs wIth bAUd RaTe, wHiCH is A BiT raTE to Be transmItTeD diviDed bY THE NumbEr oF bitS of thE modulation coDe. FOr exAMplE, if it Is assUmed ThAt the Bit ratE is B (b/S) aNd that an M-ary modUlatIon code is UseD, tHen ThE symbOL rate iS giVen By B/log 2 (M) (Symbol/sEC).
To SoLVE ThIs problem, what used tO bE TRaNsmitted In a sinGLe CaRRier mannEr Is dIvidED Into sUbcaRRiErs at a syMbol raTE tHaT does noT rEquire A sOphIstIcateD CompEnsatiOn techniQue anD Then the subcarrIErs are transmiTTeD. tHeREby, iT is Possible to sUpprESs chRomaTIc DisPErsioN and PmD, ANd AN influence of a nonlinEaR opticAl effEct.
If an orthogOnal frequeNCY Division MultIPlEXing (OFDM) modulaTion, wHich is ofteN Used in wiRelesS transmiSsion, is peRFOrmed on dAta, And ConTinUOUs Light emitted fROM a coNtInuous lIghT source Is mOduLatEd bY aN intensitY modulatOr Or A sInGle SidebANd (SSB) modUlAtoR dRivEn witH An OFDM SignaL, theN oPtICal oFDM traNSmISSion CaN bE impLemEnTed (foR exaMPle, See PateNt DocumenT 1, or nOn-PaTeNt documenT 1 or 2).    Patent DocuMeNt 1: Japanese unExaMined PATEnt AppliCation, First Publication NO. 2005-311722    non-PateNt DOcumeNt 1: ArThur James lowEry et aL., “OrTHogonaL FrequEncy DIvIsiON multiPLExIng FoR Adaptive DISPerSion COmPensAtion in long Haul WDM Systems,” oPtiCal Fiber CommuNicAtioN cOnFerENcE 2006, pDP 39 (2006)    noN-patENT Document 2: BrendoN J. C. Schmidt Et AL., “EXperimentaL demOnStratioN of 20 Gbit/S DireCT-DetectIon OpticaL OFDM and 12 GBiT/s wiTH A coLorless traNsmitter,” optical FiBEr ComMUnIcatiOn COnfereNcE 2007, PDp18 (2007). This InventIOn rElateS to a prOcEss for The maNuFacture oF premium grade coke (needle Coke) frOm petRolEum-deriveD feEDstOcks. More pArtiCularly, thiS inVenTion rElaTEs to a ProcESs
atic dispersion and a pola rization m ode d isp ers io n (P MD)in a transmiss i on f iber. Therefore, a sop histi ca t ed c o mp ensat ion tec h ni q u e i sre qui re d .In ad dit ion, in  order toobt ai n necessaryr ec eiver sens iti vity, more p owe r is r eq uir e d. Th isleads  to ap roblem  of suppr es s ing an onlinea r op tica l effect produced in the fiber such  as se lf ph a s e m odu lation (SP M) , fou r  wave m i xi n g (FW M ), or cross p hase modula t ion  (XPM) .Ina dditio n, wi th the  increase i n sy mbol rate , an o c cupiedb and for  a sin gle  ch anne l  i sexp an d ed. Th ism ake s it dif fi cu lt to  inc r e a s e th e n umbe r ofWDM channels. 
He re,s ymb ol ra te is  syn on ymous  withbaudra te, which is abitrate to b e t ra nsm it ted d i videdbythe  number  of bit s  of  t h e mo dulation code. For  e x a mp le, if i t is a s su me d  that th ebit  rat e is B(b/s )  a nd thatan M-a r ymo dulatio ncode i suse d,thent he s ymbolrate isgiven by B/log 2 (M) (symbol/sec). To s ol v e th isproblem, wh at u s ed t o be tr ans m itted  in a  s i ng l e carrier manner is  d ivided  into  subcarriersat a symbo l r ate that  doe s  n o t require a so phist icated com p ensation  tech nique an d then th e subcarri ers  ar e t ran s m it ted. Thereby, i t is  p ossible  to  suppre sschr oma tic  d ispersion  and PMD ,an dan  in fluen c e of a n on lin ea r o ptica l  effec t.
If  anor th o gon al freq u en c y  div is io n mu lti pl exing  (OF D M)modulat ion, whic h i s  oft en  u sed inwireless tran sm ission, is  p erf ormedo n  data, a nd continuous light emi t ted fro m a  cont inuo us lightsou rce is  mo d ulated  by an  inte ns ity m odula t o rorasingle sid e b and  (SSB )modu lator d riven with an OFDM sig nal, then opt ica l OF D M  t ran s mi s sio nc anb e  implemented (f or example ,s ee  Patent Do c ume nt  1, orNon-Pat ent D o cument1 or 2).   Patent  D ocum e n t 1 : Japanese  Unexami ned Paten t  Appl i ca tion,  Fi rst Pu bl ica tionNo. 20 0 5-3 11722     No n- Patent  Docu me nt 1: Ar thur James Lowery et al ., “Or thogo nal  Frequenc y D i vis ion Multi plex ing for Ad apt ive  Disp ers i on Co mpen s at ion in Lo ng H a ul WDM Sy s te ms, ” Op tical Fiber C o mmu nicat ion Confer ence  2006, PDP 39 (20 0 6)    Non-Pate nt D o c ume nt2 : Br en don J. C. Schm idt  e t al., “Ex pe rimental De monstrat io n  of 2 0 Gbit /s Dir ect-Det e c ti o n Opti calOFD M and 12Gbi t/ s  with a  c ol o rlesstran sm itter, ” Opti c al F i b er Communication  Conf e r ence2 007 , PDP 18  (2007) .  Thi s inventio n relates t o a pr oces s for  the ma nu factur e o fpremium gr a de coke ( needl e coke)  f rompet roleum -der i v ed fe edst oc ks.  More par t i cu l ar ly ,  th is i nvent io n re lates toa  process 
atic dispersion_and a_polarization mode dispersion (PMD)_in a_transmission_fiber. Therefore,_a_sophisticated compensation technique_is required. In_addition, in order to_obtain necessary receiver_sensitivity,_more power is required. This leads to a problem of suppressing a nonlinear optical_effect_produced in_the_fiber_such as self phase modulation_(SPM), four wave mixing (FWM),_or cross_phase modulation (XPM). In addition, with the increase_in_symbol rate, an_occupied band for a single channel is expanded. This_makes it difficult to increase the_number of WDM_channels.
Here,_symbol_rate is synonymous with_baud rate, which is a bit_rate to be transmitted divided by_the number of bits of the modulation_code. For example, if it is_assumed that the bit rate_is B_(b/s) and that an M-ary_modulation code is_used, then_the symbol rate_is given by B/log 2 (M)_(symbol/sec).
To solve this_problem, what used to be transmitted_in_a single carrier_manner_is_divided into_subcarriers at a_symbol_rate that_does_not require a sophisticated compensation technique_and_then the subcarriers are transmitted. Thereby, it_is possible to suppress_chromatic_dispersion and PMD, and_an influence of a nonlinear_optical effect.
If an orthogonal frequency division_multiplexing (OFDM)_modulation, which_is often used in wireless transmission, is performed on data, and_continuous light emitted from a continuous_light source is modulated_by an_intensity_modulator or a_single_sideband (SSB)_modulator driven with an OFDM signal, then_optical OFDM_transmission can be implemented (for example,_see Patent Document 1,_or_Non-Patent Document 1 or 2). _  Patent Document 1: Japanese_Unexamined Patent Application, First Publication_No._2005-311722_   Non-Patent Document_1: Arthur James Lowery et al.,_“Orthogonal Frequency Division_Multiplexing for Adaptive Dispersion Compensation in Long_Haul_WDM Systems,” Optical Fiber Communication Conference_2006,_PDP 39 (2006)   _Non-Patent_Document_2: Brendon J. C. Schmidt_et al., “Experimental Demonstration of 20_Gbit/s Direct-Detection Optical OFDM and 12 Gbit/s with a_colorless transmitter,” Optical_Fiber Communication Conference 2007, PDP18_(2007)._This_invention relates to a process for the manufacture of premium_grade coke_(needle coke) from_petroleum-derived feedstocks. More particularly, this invention relates to a process