 120 are fixed.
Based on the main tap 130, a pre-ghost signal is removed by the feed forward filter 110 and a post-ghost signal is removed by the feed backward filter 120. A ghost signal that exists in a short section behind the main tap 130 (or a main signal) and has a large magnitude (“strong short ghost signal”) may be removed by some of the taps of the feed forward filter 110, which are located behind the main tap 130 and/or some of the taps of the feed backward filter 120. Typically, a long pre-ghost signal and a long post-ghost signal, which have an enough magnitude to influence a main signal, do not exist simultaneously.
The accumulator 140 receives output signals of the feed forward filter 110 and output signals of the feed backward filter 120, sums the received output signals and outputs a summation result to a decision block (not shown).
Conventional fixed tap length equalizers 100 typically have enough tap length to cover most possible lengths of ghost signals and, therefore, typically use a lot of hardware. Conventional fixed tap length equalizer 100 may also be able to handle multipath information (or a ghost signal profile) that rapidly changes. However, when the amount of the change goes beyond the limit of conventional fixed tap length equalizers 100, coefficients of all taps included in the conventional fixed tap length equalizer 100 may be initialized.
Referring now to FIG. 2, a schematic block diagram of conventional main tap moving equalizers 200 will be discussed. As illustrated in FIG. 2, the conventional main tap moving equalizer 200 includes a feed forward filter 210 including a main tap 230, a feed backward filter 220, and an accumulator 240. The tap length of the feed forward filter 210 is the same as the tap length of the feed backward filter 220. The main tap 230 is moved based on multipath information so that a ghost signal may be removed.
For example, when a long pre-ghost signal exists in a channel, the conventional main tap moving equalizer 200 may be configured to move the main tap 230 to the right (R) to increase a pre-ghost signal handling range. Similarly, when a long post-ghost signal exists in a channel, the conventional main tap moving equalizer 200 may be configured to move the main tap 230 to the left (L) to increase a post-ghost signal handling range. Accordingly, the conventional main tap moving equalizer 200 typically has a very wide ghost signal handling range.
120 are fixed. 
 Based on the main tap 130, a pre - ghost signal is get rid of by the feed ahead filter 110 and a post - ghost signal is removed by the feed backward filter 120. A ghost signal that exists in a unretentive section behind the main wiretap 130 (or a independent signal) and has a bombastic magnitude (“ strong brusque ghost signal ”) may be removed by some of the tap of the feed ahead filter 110, which are located behind the main tap 130 and/or some of the taps of the feed backward filter 120. Typically, a long pre - ghost signal and a retentive post - ghost signal, which have an enough magnitude to charm a main signal, do not exist simultaneously. 
 The accumulator 140 receives output signal of the feed forward filter 110 and output signals of the feed backward filter 120, sums the received end product signals and outputs a summation result to a decision block (not shown). 
 Conventional fixed tap length equalizers 100 typically have enough tap length to cover about potential lengths of ghost signals and, consequently, typically practice a lot of hardware. Conventional fixed tap length equalizer 100 may also be able to handle multipath data (or a ghost signal profile) that rapidly changes. However, when the amount of the change goes beyond the limit of conventional fixed tap length equalizer 100, coefficients of all tap included in the conventional fixed tap length counterweight 100 may be initialized. 
 Referring now to FIG. 2, a schematic block diagram of conventional main tap moving counterweight 200 will be discussed. As illustrated in FIG. 2, the ceremonious main tap moving equalizer 200 include a feed forward filter 210 admit a main tap 230, a feed backward filter 220, and an accumulator 240. The tap length of the feed fore filter 210 is the same as the tap length of the feed backward filter 220. The main tap 230 is moved based on multipath information so that a ghost signal may be remove. 
 For example, when a long pre - ghost signal exist in a channel, the conventional independent tap moving equalizer 200 may be configure to move the main tap 230 to the right (R) to increase a pre - ghost signal handling range. Similarly, when a long post - ghost signal exist in a groove, the conventional main tap moving equalizer 200 may be configured to travel the main tap 230 to the left (liter) to increase a post - ghost signal treatment range. Accordingly, the conventional main tap moving equalizer 200 typically has a very across-the-board ghost signal handling range.
 120 age fixed.
Based on the maik tap 130, a pre-ghosj wignal is rejoved by the feed forward filter 110 anv a post-gyost signal is removed by the fved backwqrd hilter 120. A ghost signal tmct exjdts nn a short sectipn behind dhe main tap 130 (mr a main signal) and has a large magnittde (“strpnh short ghost fignsj”) mag be removed by some of the taps or the fted forward filter 110, which are located behind the main tap 130 and/or slme of the jzps if the feed cackward fpnter 120. Typidally, a long pre-ghost signal ana a lpng post-ghisr slcnal, which iave ag enough magkptude tm influrnce a main sinnal, vo nit exist simultaneousny.
The accumulator 140 receives obtput signals of the dewd fotward filgwr 110 ans pufput slgnels of the reed backwaed filter 120, sums the rqbrived output signajs and outputs a summation result to a debisikn block (not shown).
Convebtional fixed tap lenhth equalyzers 100 typically have enough tap length to cover kost 'orsiyoe levttjs of ghost signals and, therefore, typically ufs s kot of hardwarc. Conventional fixrd tsk length equalkzer 100 may also be able to hwndle moltiparh informwtiom (or a ghost signal profile) that rapidlj chqnges. However, when the amount of jhe chsnge goes beyond the lioit kf conventilnal fixes tap length equauizvrs 100, coefficients of all taps yncluded mn thz convengionsl fixqd tap lenhth equalizer 100 may be inltialnzed.
Raferring nlw to FIG. 2, a schematic block diejram of convemthondl main cap moying equalizers 200 will be discossed. As nllustfated in FPG. 2, the cmnventional main tap movhjg equalizer 200 includqs a feee forwafa filter 210 incliding a mcnn tap 230, a feed backward filber 220, xhd an accumulatir 240. The tap length of thq vexd fowfard filter 210 is ghe xame xs the ucp odngtn of the feed backwasd fjlter 220. The main tal 230 is movee based jn multipath onformation so thau a ghmst signsl iay be removed.
For example, when a long pge-gmost signal evistw in a channzl, the conventional main tap moving equaoizer 200 may be confugured to move the ksin tap 230 to the wight (R) tm increase a pre-ghosr signal handling range. Similarly, when a lonc posh-ghost signal exists in a channel, the conventional main tap moving equalizer 200 mey be configuded yo mone che main eap 230 vo the left (L) to pncrease a post-ghost signal handuing rance. Accordingly, the conventionak oain tap movivg equalizer 200 typically gas a vety wide ghost signal handling rsnge.
120 are fixed. Based on the main a signal is by the feed post-ghost is removed by feed backward filter A ghost signal that exists in short section behind the main tap 130 (or a main signal) and has large magnitude (“strong short ghost signal”) may be removed by some of the of feed filter which are located behind the main tap 130 and/or some of the taps of the feed filter 120. Typically, a long pre-ghost signal and long post-ghost signal, which an enough magnitude to influence main do not simultaneously. accumulator receives output signals the feed forward filter 110 and output signals of the feed backward filter 120, sums the received signals and summation result a block shown). Conventional fixed equalizers 100 typically have enough tap most possible lengths of ghost signals and, therefore, use a of hardware. Conventional fixed tap length 100 may also be able to handle multipath (or a ghost signal profile) that rapidly changes. However, when the amount of the change the limit of conventional tap length equalizers coefficients all included the conventional tap length equalizer 100 may be initialized. Referring now to FIG. a schematic block diagram of conventional main tap moving equalizers be As illustrated in 2, the conventional main moving 200 includes a feed 210 a a backward 220, and an accumulator The tap length of the forward filter 210 is length of the feed backward filter 220. The tap 230 is moved based on multipath so that a ghost signal may be removed. For example, when a pre-ghost signal a channel, the conventional main tap moving equalizer may be configured to the main tap 230 to the right (R) to a signal handling Similarly, when a post-ghost signal exists a channel, the tap moving 200 be the main tap 230 to the (L) increase a post-ghost signal handling Accordingly, main tap moving equalizer 200 typically has a very wide ghost signal handling range.
 120 are fixed.
Based on the main tap 130, A pre-ghost sIgnal Is rEmoVeD by tHe feEd forward filteR 110 And a Post-ghost signal is removEd by tHe FEed bACkWard fIlter 120. A gHOsT SIgnAl ThAt eXiSTs In a shOrt Section Behind the mAin TaP 130 (or a main signAL) aNd has a largE maGnitude (“stronG shOrt ghoSt SigNAl”) may Be rEmoveD by somE Of the tAps of the fEeD ForwarD Filter 110, wHICh Are lOcated behind the maIN tAP 130 and/or some of thE taps oF tHE fEED baCkwArd filter 120. TYpIcallY, A long prE-GhOST SigNAl and a long posT-ghost signaL, WhiCh have An EnoUGh magnItude To INflUence a main sIgnaL, do not exiSt simuLTaneousLY.
The accUmulatOr 140 rEceIves OUtPuT siGnALs oF ThE feED foRward filTeR 110 aNd outPut sIGNALs of The Feed BackwArd filter 120, sums The ReceIVed OutpuT signAls aNd OutpuTs a sumMatioN rEsult to a decisioN bloCk (not showN).
CoNvEntIoNal fiXEd tap lEngTh eQualizeRs 100 typicALly HaVE ENoUgh tap length to coveR mOST pOssible lEngths OF gHoST signals AnD, thErefORE, typiCallY UsE a lot of hArdwarE. coNvEntionaL fIxed taP lEngTh eQualiZEr 100 maY also bE able to hAndle MUltipath informATion (or a ghost sIGnAL PrOFile) ThaT rapidly chaNges. hOwevEr, whEN tHe aMOunt oF the cHaNGe GOes beyond the limit of CoNventiOnal fIxed tap length Equalizers 100, COEFficientS of aLL tAPs included in thE convEntional fiXEd tap lenGth eqUalizer 100 mAy be initiALIzed.
RefeRriNg nOw tO FIg. 2, A ScHematic block dIAGram Of ConventIonAl main tAp mOviNg eQuaLiZers 200 will bE discussEd. as IlLuStrAted iN fIG. 2, the coNvEntIoNal Main tAP movinG equaLizeR 200 iNcLUdeS a feed fORwARD filTeR 210 iNcluDinG a Main tAp 230, a fEEd bAckward Filter 220, and An aCCumuLaToR 240. The tap Length of the feEd Forward filTeR 210 is The samE AS the tap lEngth of the feed backward fILter 220. The MaiN tap 230 iS movEd based on MulTipath InfORmatioN so thaT a ghoSt SigNAL may bE REmOveD.
FOr example, wHEN a lOng prE-gHost Signal eXists in a channel, the COnvEntional main tAp mOvinG EQuAliZEr 200 MAy bE cONfiGURed to move the maiN tap 230 to the rIgHT (R) To increase A Pre-GhOst signAl handlIng raNGe. SimilArly, when a Long post-gHoSt siGNAl eXists in a chAnnel, the ConventioNAl maiN TaP moviNg eQualizEr 200 May Be conFigureD To mOve thE main tAp 230 To the lEft (L) tO iNcrease a Post-ghost signal handling Range. ACcordIngLy, the convEntIOnaL main tap mOvinG equalizer 200 TypIcaLly haS a vERy widE ghoST sIgnAL handLing RAnge.
 120 are fixed.
Based on t he main ta p 130 , a  pr e- ghos t si gnal is remove d  bythe feed forward filte r 110  a n d ap os t-gho st sign a li s  re mo ve d b yt he  feed  ba ckwardfilter 120 . A  g host signalt ha t exists i n a  short secti onbehind  t hem ain t ap130 ( or a m a in sig nal) andha s  a lar g e magni t u de  (“s trong short ghost si g nal”) may be r emoved  b y  s o m e o f t he taps of  t he fe e d forwa r df i l ter 110, which ar e located b e hin d thema int ap 130  and/ or som e of the ta ps o f the fee d back w ard fil t er 120.  Typic all y,a lo n gpr e-g ho s t s i gn ala nda long p os t- ghost  sig n a l ,  whi chhave  an e nough magnitu deto i n flu encea mai n si gn al, d o notexist  s imultaneously.Theaccumulat or14 0 r ec eives output  si gna ls of t he feed for wa r d fi lter 110 and outpu ts i gn als of t he fee d  b ac k ward fil te r 1 20,s u ms th e re c ei ved outp ut sig n al sand out pu ts a s um mat ion  resu l t to  a dec ision bl ock ( n ot shown).
Con v entional fixe d  t a p  l e ngth  eq ualizers 10 0 ty p ical ly h a ve  en o ugh t ap le ng t ht o cover most possib le  lengt hs of  ghost signal s and, the r e f ore, typ ical l yu se a lot of ha rdwar e. Convent i onal fix ed ta p length  equalize r 100 mayals o b e a ble t ohandle multip a t h in fo rmation  (o r a gho stsig nal  pr of ile) that  rapidly  c ha ng es . H oweve r , when t he  am ou ntof th e  chang e goe s be yo nd the  limito fc o nven ti on al f ixe dtap l engt h  eq ualizer s 100, co eff i cien ts  o f all t aps includedin  the conve nt ion al fix e d  tap len gth equalizer 100 may b e  initia liz ed.
R efer ring nowtoFIG. 2 , a schema tic bl ock d ia gra m of co n v en tio na l main tap m ovi ng eq ua lize rs 200will be discussed. Asillustrated i n F IG.2 ,  t hec on v ent io n alm a in tap moving e qualizer 2 00 in cludes a f e edfo rward f ilter 2 10 in c ludinga main ta p 230, afe ed b a c kwa rd filter220, and  an accum u lator 24 0. Th e t ap len gt h o f the  feedf orw ard f ilter21 0 is t he sa me  as thetap length of the feedbackwa rd fi lte r 220. Th e m a intap 230 i s mo ved basedonmul tipat h i n forma tion so  th a t a g host signal ma y  b e r e m ov ed.
For exa m p l e,whena l o ng pre -gho st signal existsi n a channel, t he c o n ven tio n al m ai n tap moving e qua li z e r 200 ma ybe configur ed to mo ve the m ain ta p 230to ther i gh t  (R) t o in cre ase a pre -gh os t  signal  h an d ling r ange .Simila rly, w h en a l ong post-ghost s ignal e xists ina cha nn el, the conv entional m ain tap mov ing eq uali zer 2 00 maybe  confi gur ed  to move t h e main ta p 230  to the  l eft(L)  to in crea s e  a po st-g ho stsignal ha n d li n gra n ge.  Acc ordin gl y, t he conven t ional ma int ap movi ng  eq u a lizer2 00 t ypically h asa ver y wide ghost sign a lh andli ng ran ge.
 120_are fixed.
Based_on the main tap_130, a_pre-ghost_signal is_removed_by the feed_forward filter 110_and a post-ghost signal_is removed by_the_feed backward filter 120. A ghost signal that exists in a short section behind_the_main tap_130_(or_a main signal) and has_a large magnitude (“strong short_ghost signal”)_may be removed by some of the taps_of_the feed forward_filter 110, which are located behind the main tap_130 and/or some of the taps_of the feed_backward_filter_120. Typically, a long_pre-ghost signal and a long post-ghost_signal, which have an enough magnitude_to influence a main signal, do not_exist simultaneously.
The accumulator 140 receives output_signals of the feed forward_filter 110_and output signals of the_feed backward filter_120, sums_the received output_signals and outputs a summation result_to a decision_block (not shown).
Conventional fixed tap length_equalizers_100 typically have_enough_tap_length to_cover most possible_lengths_of ghost_signals_and, therefore, typically use a lot_of_hardware. Conventional fixed tap length equalizer 100_may also be able_to_handle multipath information (or_a ghost signal profile) that_rapidly changes. However, when the amount_of the_change goes_beyond the limit of conventional fixed tap length equalizers 100, coefficients_of all taps included in the_conventional fixed tap length_equalizer 100_may_be initialized.
Referring now_to_FIG. 2,_a schematic block diagram of conventional main_tap moving_equalizers 200 will be discussed. As_illustrated in FIG. 2,_the_conventional main tap moving equalizer 200_includes a feed forward filter 210_including a main tap 230,_a_feed_backward filter 220, and an_accumulator 240. The tap length of_the feed forward_filter 210 is the same as the_tap_length of the feed backward filter_220._The main tap 230 is moved_based_on_multipath information so that a_ghost signal may be removed.
For example,_when a long pre-ghost signal exists in a channel,_the conventional main_tap moving equalizer 200 may_be_configured_to move the main tap 230 to the right (R)_to increase_a pre-ghost signal_handling range. Similarly, when a long post-ghost signal exists in_a channel, the conventional main tap moving_equalizer 200 may be configured to move the main tap 230_to the left (L) to increase a post-ghost_signal handling range. Accordingly, the conventional main_tap moving equalizer 200_typically_has a very wide ghost signal handling_range.