PARAMETER ESTIMATION OF A SWEEP-SPREAD CARRIER SIGNAL FOR ADVANCED ACOUSTIC COMMUNICATION VIA MULTIPATH SHALLOW WATER CHANNELS

Transcription

1 PARAMEER ESIMAION OF A SWEEP-SPREAD CARRIER SIGNA FOR ADVANCED ACOUSIC COMMUNICAION VIA MUIPAH SHAOW WAER CHANNES K.Kebkal, A.Kebkal, R.Baash, S. Yakovlev Kosai G. Kebkal, Sae Oeaaiu of Ukaie, 7 Eoovskaa, 994 Sevasool, Ukaie, kebkal@ua.f Alexe G. Kebkal, U-Beli, Akes , ACK1, Beli, Gea. Rudolf Baash, Evoois GbH, Sokowes. 7, 1369 Beli, Gea. See Yakovlev, Evoois GbH, Sokowes. 7, 1369 Beli, Gea. o ovide a axiu effe dui aliaio of he Swee-Sead Caie ouiaio ehod, basi aaees of a swee-sead sial, suh as feque adie, duaio ad ie aaee of swees i he sead sequee, us oleel ah o asii hael. Owi o ado vaiaios of uliah suues i aial asii haels, howeve, bes suiable aaees of he swee-sead sial ae uediable. I he ae a ehique is eseed ha ealizes esiaio of a oial se of sead sial aaees fo aousi ouiaio via uliah shallow wae haels. Siulaios as well as exeieal esuls fo ee shallow wae ials ae ovided. 1. INRODUCION I oe of evious aes of he auhos a udewae elee ehod was iodued, whih uses a swee-sead aie SC fo obai effes of uliah oaaio [1]. he SC asii sial is ive b exessio s, whee Re{ } is he eal a of he value i baes, is a aowbad sial oaii use ifoaio, is he swee-sead aie: os, 1 osisi of seies of feque odulaed seios swees, i whih deoes he feque vaiaio ae o feque adie:

2 H, sw whee ad H ae eseivel he lowes ad hihes aula fequeies, sw is he swee duaio, he e / sw deoes he oead fo uai he value o he eaes leas iee, ad с is a aual le ie wih he le duaio sw : sw. he sw aes [1] ad [] eese ha afe oaaio of suh aie ove a uliah hael he eeive sials a be wie as z os, 3 whee,, aival ovided b he dela i, ad sw < siifies he feque deviaio of a i-h uliah, sw, < is he hase of he i-h uliah aival. Reeive sial osis of a ube of uliah aivals, whih ae shifed o ol i ie, bu also i feque, wheeb he seee he swees, he oe feque seaaio ha a be ahieved. his eeses ioa esul ovidi a ooui o esolve uliahs i feque doai. Evidel he seaaio of uliahs is ol ossible if he ouiaio sse is oel shoized wih oe of uliah aivals efeabl wih he oe oweful oe. I his ase, i esul of deodulaio he ieediae feque of he sial aivi ove his ah is equal o zeo. A aliaio of a low ass file PF beoes easoable o effeivel suess o iiize he uliah iefeee.. SYNCHRONIZAION AND CARRIER ADJUSMENS o ovide a oial se of aie aaees ii, feque adie, swee duaio, beii hase of shoous uliah aival, a sho shoizaio eable osisi of a seies of swees is asied ove he aual udewae aousi hael. Reeived sials ae oessed i es of ideifiaio of ee disibuio bewee aivals hei fequeies iside of he ue uliah iesi ofile. Suh oessi is aied ou via alulaio of auo-oelaio fuio of he eable sial. he fis aaee o be esiaed is he dela of he os oweful aival i he ixue of eable s uliahs. he eeivi ie of suh aival is eiseed as shoizaio ie. Exisi shoizaio aloihs fo auae ii esiaio ae usuall oo olex o wok i eal ie. heefoe he shoizaio oedue is divided hee is wo saes. he fis oe is fo aoxiae ii evaluaio. he seod oe is fo eise shoizaio ie esiaio. e a eeivi saio sas i a lise ode ad aalzes he oe of eeivi buffe b eas of a eable-deeo, whih is sile eouh o wok i eal ie. Iu sales ee he buffe, whose oe is saed looki fo he eable sial. If o sial is deeed o he diialized ie ieval, he buffe is leaed ad he ex sale seies is

3 ake o he buffe, aalzed, ad so o uil he shoizaio eable is deeed. Afe deeio he oe of he buffe follows o he ex ui, whih ouus a veo of oelaio bewee he deeed sial ad he exeed eable sial. e he deeed sial z is desibed wih exessio 3 ad exeed sial wih exessio 1 ad le ow exaie he buffe oe. If he oelaio fuio is alulaed b eas of he ool used foula z d z R * ˆ, 4 he, befoe looki fo he osl oweful uliah aival, all siifia aivals idexes -1 db ae defied. Assui ha he abie oise is Gaussia oe, he idex of he os oweful aival iside of he oelaio veo will be foud fo he exessio: ˆ ax a ˆ z R. 5 hus he auae shoizaio ie oises he value: ˆ ˆ s. he seod aaee o be esiaed is he beii hase of he shoous uliah aival. o ovide i, he shoizaio eable is ulilied a ie s ˆ wih he heeode sial ad is quadaue sulee. I esul, he sial aeas: i s, 6 whee H z os os } Re{ * 7 s s H z si si } I{ * 8 he ih side of he exessios 7 ad 8 osis of 3 ies. he fis ad seod oe aea i esul of shoous uliliaio of he os oweful uliah aival ad he heeode. he fis ie oais a ieediae feque diffeee feque, whih is equals o zeo, ad he desied hase. he seod ie, aa fo he hase, oais he doubled beii feque ad he doubled feque adie. he hid ie oais he es uliahs: os os 9 s si si 1 hus, havi oe shoizaio, he ieediae feque of ol oe uliah aival, ael he os oweful oe, is equal o zeo. he es aivals, owi o diffee aival ies ah lehs, ae feque shifed i ese i o he aou of see

4 exessio. his feaue of he swee-sead aie is used fo seaaio of uliah aivals i feque doai b eas of a low ass file ad, i his wa, fo eliiaio o siifia suessio of uliah iefeee. If he PF is a ideal oe, i ouus a followi fileed sial: z PF{ } os i si 11 As follows fo 11, he PF ouus a sial, whih is eeseed wih ol oe uliah aival, ad a auae hase esiae a be foud as k a I z / Re z. he hid aaee o be esiaed is he feque adie of he swee-sead aie, whih ovides a eessa feque esoluio of he os oweful aival fo he es uliah aivals. o efo his, he esul of uliah ofile aalsis via alulaio of ˆ, ael he se of ie idexes of he siifia aivals, is used, wheeb he R z iiu ie dela i bewee he os oweful uliah aival ad he ex aival ovides hei feque esoluio i aodae wih exessio i, whee deoes he feque adie of he swee-sead aie ad is ive b 3. As follows fo he foula a eessa feque esoluio fo a eai ie seaaio i ive b hael aue a be ovided via adjuse of he feque adie se b he ouiaio sse. he adie us be se o a value, whih akes he feque esoluio bewee he os oweful uliah aival ad he ex aival bi eouh o a ou he low ass filei of a suffiie quali. Fo exale, if a sbol ae o feque bad ouied wih a sbol W is ive, he suh a feque adie us be se fo a ive uliah ofile, ha he followi iequali beoes ue: W. 1 i Adjusi he feque adie, howeve, wo oa edeies us be ake io aou. he less he dela i, he hihe feque adie of he SC ha us be se o ovide he eessa feque esoluio of he shoous uliah aival ad oesodil, he eessa daa ae. O he ohe had, he hihe he feque adie, he shoe he swee duaio ha a be used. If he duaio beoes oo sho, he ue aivals of he swee a iefee wih ail aivals of a evious swee. A ooise has o be foud, howeve, he swee le sw us eeall exeed hael s dela sead. his liis he axiu value of feque adie, so ha he followi iequali us be ke ue: H, 13 ad o he base of 1 ad 13 he value a be defied b he sse of iequaliies: W i H 14

5 If he soluio of he sse 14 is a uliude of, he he os favoable of he is suh oe, whih ovides he loes duaio of he swee ad oesodil he os ee ouu fo lae asissio disaes. his a be doe if he si of iequali i 14 will be elaed wih he si of equali. If he soluio of he sse 14 is he ull se, he he axiu daa ae ha a be ahieved i he ue hael a be defied i aodae wih he exessio: W ax i. o o-odiae he aaee se bewee asie ad eeive, a feedbak essae is o be oveed bak o he asie, eihe o edefie he swee adie fo a ive daa ae, o i oa, o seif aohe daa ae fo he adie iiiall used. 3. EXPERIMENS Resuls of field ials ae eseed i his seio. I a shallow wae hael a shoizaio eable followed b daa akes was asied, wheeb a oial aaee se of he swee-sead aie, whih was esiaed via eal-ie oessi of he eable, allowed o ahieve a oial daa ae i he ue asissio hael. Chael haaeizaio. o evaluae he oe of a ue asii hael, a eable sial osisi of a sequee of liea swees was used. he ou a boade feque bad ad ae loe ha he aie sees used i daa seio. he feque of he eable sial was swe fo 4 o 9 khz, ad he leh of aie see was 5 s. o sees eeseed he uliah hael suue oe leal. Fi. 1. Exales of iulse esoses of he uliah aousi hael Afe alulaio of he oelaio fuio Rˆ z he uliah suue of he hael was eeseed wih a sequee of oelaio iks, whose ie idexes, fos ad aliudes haaeized he uliah suue of he ue hael. Fi. 1a ad 1b deosae soe exales of uliah ofiles of he exeieal hael used. Dui he ials ues ad wid aivi idued soe haes i exeieal se u asii disae ad deh, hus he hael s uliah suue was oiuousl odified. he uliah suue was eeseed b 3 o 4 esoses. Ou eeaed obsevaios have show ha owe fluuaios i he uliah ooes wee abou o 3 db. Dela bewee he wo fis esoses was abou µs, whih aoxiael aeed wih he heoeial dela of he sial efleed fo he sufae. he ie ieval ouied b he whole uliah esose sequee was esiaed o be 4 µs. Delas of he

6 uliah ooes eaied sable dui he ie eessa fo asii a blok of daa followi afe he shoizaio seio. Suue ad Paaees of asied Sials. he daa wee asied i akes i fo of bia sequees osisi of 5-1 ifoaio sbols. he sequees wee odued b a sadad quasi-ado-ube eeao wih fixed iiial odiios. he diffeeial bia hase shif kei was alied o fo aowbad diial sials sbols. he aie had he fo of a sequee of feque-odulaed sees, whih followed wihou ievals. he aie feque was swe fo 4 o 8 khz. he leh of he swee-sead aie sees i diffee exeies was.3 o s. Aodil, he feque adie was o 133 khz/s. he sbols wee 8 o 5 µs lo. he daa ae was o 1 kbi/s. Sial Poessi. Afe shoizaio of he eeive wih he ie of he os oweful uliah aival, evaluaio of a oial feque adie was aied ou. I aodae o he aloih above, i ode o eove iesbol iefeee, he feque adie ad he leh of aie sees wee hose so ha uliah ooe of he ue see did o ovela wih hose of he ex oe, o he ovela was isiifia. Afe ha he oedue of eeive sial oessi was aied ou, followed b he deodulaio ad esiaio of diial ifoaio asied ove he hael. If oel shoized, he low-feque ae oaied he eal ieediae feque, whih was zeo fo he useful uliah ooe, ad a ube of seal lies, whih eeseed udesiable uliah ooes shifed i ie ad feque. Sie he diffeeial hase shif kei was used, he asied sial was deeied b he hase diffeee bewee oseuive ulses aowbad diial sials. Phase diffeee wihi ±9 efeed o loial zeo, while hase diffeees wihi 18±9 efeed o loial ui. Below, we ovide a exale of asii a sequee of bia sials houh a shallow uliah udewae hael illusaed i Fi. 4. Fi.. Disibuio of diffeeial hase ales o eeive side he daa ae was 1.4 kbi/s. he aie was odulaed b sweei is feque fo 4 o 8 khz wih a feque adie of 83.3 khz/s. he leh of he aie see was 48 µs. o oesae fo he ieulai of he asii volae esose, he aliude of he aie sees was oeed so ha he eied sial had aoxiael he sae aliude ove he oeai feque ae. he aie faes wee divided io five as, eah of he oaii a 96 µs lo hase shif keed sbol. he soud-o-oise aio was abou 11.5 db dui he asissio of he daa blok. Phase ales of he eeived sbols ae illusaed i Fi. 5. Desie he oaaivel so sae i boh aula seos, he diial values of he hase shif keed sbols ae

7 well disiuishable. o esiae he eo level, we subaed he kow diial sequee odue b he soue fo he sequee oessed b he eeive ad sulied o he eiie. hee wee 9 eos alos uifol disibued ove 7 asied sbols, so ha he asissio eo obabili alulaed as he aio of he ube of eo sbols o he leh of he asied sequee was.15. Fo he sake of oaiso, ohe daa aes ad feque adies wee esed. he bia hase shif kei was also used. he asied daa akes wee 5 bi lo. Fo 165 µs sbols o daa ae of 661 bi/s ad 8 µs lo aie sees, he eo obabili i he daa asissio ove 3 was esiaed as.91. Afe he ae was edued o 1, he daa wee eeived wihou eos. REFERENCES [1] K. G. Kebkal ad R. Baash, Swee-sead aie fo udewae ouiaio ove aousi haels wih so uliah oaaio, J. Aous. So. A., vol.11, [] R. Baash ad K. Kebkal. Pae PC/EP/1333.