DVB-T Digital Terrestrial Television Transmission over Fading Channels

Transcription

1 96 T. KRATOCHVÍL, R. ŠTUKAVEC, DVB-T DIGITAL TERRESTRIAL TELEVISIO TRASMISSIO OVER FADIG CHAELS DVB-T Dgtal Trrstral Tlvson Transmsson ovr Fadng Channls Tomáš KRATOCHVÍL, Radm ŠTUKAVEC Dpt. of Rado Elctroncs, Brno Unvrsty of Tchnology, Purkyňova 118, 61 Brno, Czch Rpublc Abstract. Th papr dals wth th transmsson of th dgtal tlvson sgnal accordng to th DVB-T standard n SF ntwork ovr fadng channls for th fxd rcpton. Th laboratory transmsson systm for th ral broadcastng basd on R&S RF tst and masurng qupmnts s prsntd ncludng th transmsson paramtrs stup. Th rsults of broadcastng ovr Gausan, Rcan and Raylgh channls and rsults of th cho mparmnts ar prsntd and dscussd wth th thory and smulaton rsults. Th BER bfor and aftr Vtrb dcodng and accordng to MER qual to S/ rato n th channl from th constllaton dagram wr compard n all transmsson xprmnts. Addtonal pctur qualty valuaton s prsntd usng DVQL-W mtrc that montors blocknss structurs n MPEG- comprssd pcturs and gvs notc of known clff-off ffct. Kywords Dgtal Trrstral Transmsson, Gaussan channl,, Raylgh channl, DVQL, DVB-T. 1. Introducton Dgtal Vdo Broadcastng Trrstral (DVB-T) s a tchncal standard dvlopd by th DVB Projct that spcfs th framng structur, channl ncodng and modulaton for Dgtal Trrstral Tlvson (DTT) broadcastng. It s a flxbl systm that allows ntworks to b dsgnd for th dlvry of a wd rang of srvcs, from SDTV (Standard Dfnton TV) to HDTV (Hgh Dfnton TV), fxd, portabl, mobl and vn handhld rcpton (n conjuncton wth standard DVB-H for mobl TV trmnals that was bult on th provn mobl prformanc of DVB-T). DVB-T uss Codd Orthogonal Frquncy Dvson Multplx (COFDM) modulaton. Ths typ of modulaton uss a larg numbr of subcarrrs and dlvrs a robust sgnal that has th ablty to dal wth varous transmsson channl condtons (fadng ncludd). DVB-T tchncal charactrstcs mak DTT systm flxbl to oprat n combnaton of: 3 modulaton optons (QPSK, 16-QAM, 64-QAM), 5 dffrnt FEC (forward rror corrcton) rats, 4 Guard Intrval optons (1/3, 1/16, 1/8, 1/4), mods of usd carrrs - k (175) or 8k (6817), 3 channl bandwdths opton (8, 7, 6) MHz. Usng dffrnt combnatons of th abov paramtrs a DVB-T ntwork can b dsgnd to match th rqurmnts of th ntwork oprator, fndng th balanc btwn robustnss and capacty. Th us of COFDM modulaton wth th approprat Guard Intrval allows DVB-T to provd srvc n th Sngl Frquncy twork (SF). SF s a ntwork whr a numbr of transmttrs oprat on th sam RF frquncy and must b synchronzd n tm and frquncy. SF can covr a country ara or can b usd to nhanc ndoor covrag usng a smpl gap-fllr.. Bascs of th DTT Transmsson Th dstrbuton of DTT tlvson programs by way of trrstral transmttrs s th classcal tchnology of broadcastng. Rcvd sgnal n good qualty should b ntrprtd as th ovrall ffct, th sum of varous nfluncs ncludng th many possbl dsturbancs cratd by nos, chos, SF co-channls and ntrfrnc (s Fg. 1). Th consdrabl drctvty of th rooftop antnna, apart from th sgnal powr obtand by th gan, can partally rduc cho mparmnts causd by rflcton from hlls, buldngs tc. A good rooftop antnna guarants th vwrs srvc wth satsfactory qualty..1 Gaussan Channl (AWG) Th rcpton condtons wthn th srvc ara can b dscrbd by th so-calld Gaussan channl modl, whch s basd on a drct sgnal path from transmttr to rcvr. Ths channl s ovrlad wth addtv wht Gaussan nos (AWG) whch s manly producd n th rcvr tslf.

2 RADIOEGIEERIG, VOL. 17, O. 3, SEPTEMBER 8 97 A smulaton of th powr rqurmnts for th trrstral DVB-T standard appld th followng mathmatcal modl to dscrb th channls wth chos quatons (1) and (). A crtan numbr of chos can b takn nto consdraton. Th output sgnal y(t) of th channl modl s dscrbd as a functon of th nput sgnal x(t). As dscrbd bfor, th channl modls ar [3]: (RC) Fg. 1. Multpath rcpton n DTT llustraton of drct path and dlayd cho sgnals nflunc on rcvr rspons.. Rcan Channl In ordr to nclud th mparmnts causd by chos t s ncssary to nlarg th channl modl. Th transmsson path known as, taks nto account th ffct of multpath sgnals n addton to nos and to th domnatng drct sgnal path btwn transmttr and rcvr. Th statstcs of ths multpath sgnals ar approxmatd by a Rcan dstrbuton. y( t) = jπθ x( t) + x( t t ) 1 Raylgh channl (RL) y( t) = 1 jπθ x( t t ) (1) ().3 Raylgh Channl Th movmnt of th rcvr durng rcpton can caus changs to th rcpton condtons, partcularly nsd buldngs. Rod antnnas on portabl rcvrs brng no notcabl antnna gan or drctvty. Rqurmnts for trrstral dgtal tlvson n Europ dfn th statonary rcpton wth a portabl rcvr. In comparson to th rcpton wth a rooftop antnna ths lmtaton mans that t can not b takn for grantd that a drct sgnal path would domnat. Th smulaton of th channl modl dscrbs th drct path lmnatd. Th transmsson channl modl wth chos of mor or lss qual prorty s calld Raylgh channl. Th dstrbuton of chos corrsponds to a Raylgh dstrbuton. 3. Transmsson Channls Smulaton Rcpton wth a rooftop antnna can b vwd as statonary rcpton and th drctvty of th antnna can b usd thr for th slcton of th drct sgnal or at last for choosng a domnant cho sgnal as th man rcpton sgnal. A typcal hom rcvr oprats wth rooftop antnna, whch should hav a gan of approx. 7 db (VHF) or 1 db (UHF) [1]. As opposd to analogu tlvson (ATV), n whch chos ar mor or lss vsbl n th form of doubl contours on th scrn, chos n th cas of DVB-T multpl sgnal rcpton caus an ncras n ntrsymbol ntrfrnc (ISI). Ths ultmatly rsults n an ncras n th btrror rat (BER). Ths ncras must thn b corrctd by ncrasng th transmsson powr [1], []. whr s th attnuaton n th drct sgnal path, s th crtan numbr of chos, s th attnuaton n cho path, Θ s th phas rotaton n cho path, and t s th rlatv dlay tm n cho path. Th Rcan factor K dnots th rato of th sgnal n th drct path to th sum n all cho paths [1]: K =. (3) = For th masurmnt of th a Rcan factor K = 1 db has bn usd, as suggstd n [1]. In ths cas: = = 1. (4) Rcan factor s K = n cas of Raylgh channl smulaton, as thr s no drct path n ths channl typ. Factor K qual to 1 was usd n smulaton. A comparson of th rsults of smulatons, n trms of carrr-to-nos rato (C/) rqurd for quas-rror fr (QEF) rcpton of a DVB-T sgnal n th Gaussan channl, wth th rspctv valus n th Rcan Channl shows, as xpctd, that th has hghr rqurmnts. Th addtonal rqurmnt s actually n th rang of (.3 1.1) db, accordng to th systm paramtrs (numbr of nnr modulaton stats, convolutonal cod rat, hrarchy codng, tc.). An ncras n th transmsson powr by a maxmum of 3% s rqurd to compnsat th ffct of chos [1].

3 98 T. KRATOCHVÍL, R. ŠTUKAVEC, DVB-T DIGITAL TERRESTRIAL TELEVISIO TRASMISSIO OVER FADIG CHAELS Lk th, th Raylgh channl, n comparson to th Gaussan channl, also rqurs hghr C/ rato. Smulaton rsults show that for an rror-fr rcpton (agan accordng to th systm paramtrs) C/ s rqurd up to 9 db hghr. An ncras n th C/ by approx. 9 db would rqur an ght tms hghr transmsson powr. Ths ncras s not ralstc [1]. Th portabl rcvr thrfor s affctd by th lack of gan n th rcvng antnna (gan of 1 db n th UHF band, most rlvant to th DVB-T) and by th sgnal dtroraton n th Raylgh channl. Furthr losss occur du to th fact that th rcpton antnna s oftn nsd a buldng and oftn clos to th ground lvl, whl an antnna hght of 1 m from a ground lvl s assumd n th calculaton of th covrag. Th smulaton rsults wr computd on th assumpton that a prfct corrcton of th channl frquncy rspons has takn plac n th trms of attnuaton and phas rotaton. Phas nos as a sourc of rrors wthn th rcvr was not consdrd. Th C/ rato was dtrmnd at whch th channl BER bfor Vtrb for th rat of /3 or 3/4 s qual to or lss than 3E- and BER aftr Vtrb dcodng of nnr rror protcton s qual to or lss E-4. Ths condton fnally lads to practcally rror-fr sgnals (QEF) and at th nput of th MPEG- dmultplxr BER s qual to or lss than 1E-11 [4]. In cas of th DVB-T transmsson n th SF wth systm paramtrs (64-QAM, mod 8k, convolutonal cod /3, Guard Intrval 1/8) th rqurd C/ rato n db and non-hrarchcal modulaton s qual to [3]: 16.5 db for Gaussan channl (AWG), 17.1 db for (RC paths), 19.3 db for Raylgh channl (RL paths). As xpland bfor, th smulaton of th Rcan channl rprsnts an approxmaton of th actual condtons whn rcvng DVB-T sgnals va a rooftop antnna wth hgh drctvty. Th Raylgh channl s usd to modl th actual condtons whn rcvng DVB-T sgnals va statonary rcvrs, whch hav a rod antnna. A clos analyss of th numrcal valus lads to th followng thortcal conclusons: Th transton from th Gaussan channl to th, wth th sam typ of modulaton and constant cod rat, rsults n ncssary ncras n th C/ by a maxmum 1.1 db, Th transton from th Gaussan channl to th Raylgh channl, wth th sam typ of modulaton and constant cod rat, rsults n ncssary ncras n th C/ by a maxmum 8.9 db. 4. DVB-T Laboratory Transmsson Th DVB-T transmsson systm dals wth th transmttr and rcvr sds (s Fg. 8). Th transmttr sd conssts of th DVB-T/H tst transmttr wth varabl DVB-T/H systm paramtrs and MPEG- TS gnrator wth th MPEG- MP&ML comprssd vdo. Usd RC profls (s Fg. and Tab. 1) and RL profls (s Fg. 3 and Tab. ) [5] accords to [3]. Ths ar: R&S SFU DVB-T/H tst transmttr (111.5.), R&S SFU MPEG- TS gnrator (111.5.), R&S SFU K-4 (nos gnrator) - AWG, R&S SFU B-3 (fadng smulator), - RC and RL. Th rcvr sd conssts of th DVB-T tst rcvr wth th MPEG- dcodr opton, MPEG- TS, dgtal vdo qualty analyzr and st-top box. Ths ar: Kathrn MSK-33 DVB-T tst rcvr Rx1, R&S DVQ vdo qualty analyzr ( ), STB Humax F3 FOX-T DVB-T hom rcvr Rx. Th MPEG- TS output of th DVB-T tst rcvr s connctd to th MPEG- TS analyzr (pctur rrors chck and ts statstcs). Th pctur analyss masurs ar avalabl only f th PAT (Program Assocaton Tabl) s dcodd n th DVB-T tst rcvr. Th DVB-T systm transmsson paramtrs for all xprmntal masurmnts wr st to Europan most convnnt typ of DTT broadcastng. Ths paramtrs ar most charactrstc for th SF ntworks: RF lvl 6 dbuv (mdum snstvty of th Rx), 8 MHz channl (sgnal bandwdth of 7.68 MHz), 64-QAM modulaton (max. TS of,11765 Mbt/s), 8k mod 6817 subcarrrs (fxd rcpton), /3 convolutonal cod rat (robust protcton), 1/8 Guard Intrval (mdum sz of SF ntworks), non-hrarchcal modulaton (on TS transmsson). Th rsults of achvd rror-rats bfor and aftr Vtrb dcodng wr valuatd wth th varous C/ [db] n th lnar transmsson channl. In advanc th modulaton rror-rat MER [db] from constllaton dagram analyss and wghtd dgtal vdo qualty lvl DVQL-W [-] was automatcally masurd. Masurmnts wr don n th laboratory of dgtal tlvson at th Dpartmnt of Rado Elctroncs, Brno Unvrsty of Tchnology.

4 RADIOEGIEERIG, VOL. 17, O. 3, SEPTEMBER 8 99 Rcan Channl 6 paths accordng to ETSI E AX B Raylgh Channl 6 paths accordng to ETSI E AX B a) RC6 AX B profl (6 paths) a) RL6 AX B profl (6 paths) Rcan Channl 1 paths accordng to ETSI E AX B Raylgh Channl 1 paths accordng to ETSI E AX B b) RC1 AX B profl (1 paths) b) RL1 AX B profl (1 paths) Rcan Channl paths accordng to ETSI E AX B Raylgh Channl paths accordng to ETSI E AX B c) RC AX B profl ( paths) c) RL AX B profl ( paths) Fg.. profls usd for th transmsson. Fg. 3. Raylgh channl profls usd for th transmsson. Path numbr Loss [db] Dlay [us] Phas [dg] Tab. 1. profl RC6 AX B spcfcaton (rducd numbr of 6 paths wth th hghst ampltud s oftn suffcnt for practcal mplmntaton [3]). Path numbr Loss [db] Dlay [us] Phas [dg] Tab.. Raylgh channl profl RL6 AX B spcfcaton (rducd numbr of 6 paths wth th hghst ampltud s oftn suffcnt for practcal mplmntaton [3]).

5 1 T. KRATOCHVÍL, R. ŠTUKAVEC, DVB-T DIGITAL TERRESTRIAL TELEVISIO TRASMISSIO OVER FADIG CHAELS Raylgh channl 1,E+ AWG rf. RC6 AX B RC1 AX B RC AX B 1,E+ AWG rf. RL6 AX B RL1 AX B RL AX B 1,E-1 1,E-1 BER bfor Vtrb [-] BER bfor Vtrb [-] 1,E-5 a) BER bfor Vtrb dcodng (channl BER) 1,E-5 a) BER bfor Vtrb dcodng (channl BER) Raylgh channl AWG rf. RC6 AX B RC1 AX B RC AX B AWG rf. RL6 AX B RL1 AX B RL AX B BER aftr Vtrb [-] QEF 1,E-5 1,E-6 1,E-7 BER aftr Vtrb [-] QEF 1,E-5 1,E-6 1,E-7 1,E-8 1,E-8 1,E-9 1,E-9 b) BER aftr Vtrb dcodng b) BER aftr Vtrb dcodng Raylgh channl AWG rf. RC6 AX B RC1 AX B RC AX B AWG rf. RL6 AX B RL1 AX B RL AX B 3 3 MER [db] MI MER [db] MI 1 1 c) MER from constllaton analyss c) MER from constllaton analyss Raylgh Channl 1 AWG rf. RC6 AX B RC1 AX B RC AX B 1 AWG rf. RL6 AX B RL1 AX B RL AX B 8 8 DVQL-W mn [%] 6 4 DVQL-W mn [%] 6 4 d) mnmal DVQL-W mtrc wth DVB-T clff off ndcaton d) mnmal DVQL-W mtrc wth DVB-T clff off ndcaton Fg. 4. rsults as a functon of C/ rato for fadng channl profl F1 (RC AX B for th fxd rcpton wthout Dopplr shft). Fg. 5. Raylgh channl rsults as a functon of C/ rato for fadng channl profl P1 (RL AX B for th portabl rcpton wthout Dopplr shft).

6 RADIOEGIEERIG, VOL. 17, O. 3, SEPTEMBER 8 a) AWG wth db MER = 1.5 db b) AWG wth 3 db MER = 8.7 db c) AWG wth 4 db MER = 3.9 db d) RC wth db MER =.5 db ) RC wth 3 db MER = 7.8 db f) RC wth 4 db MER = 3.4 db g) RL wth db MER = 16.5 db h) RL wth 3 db MER = 4. db ) RL wth 4 db MER = 7.3 db 11 a) fram wthout blockng artfacts DVQL-W btwn (8 6) ndcats good vdo qualty b) fram wth blocknss DVQL-W btwn (6 4) ndcats far vdo qualty c) fram wth rror concalmnt DVQL-W btwn (4 ) ndcats poor vdo qualty d) pctur frz and clff off DVQL-W btwn ( ) ndcats bad vdo qualty Fg. 7. MPEG- comprssd dgtal vdo fram and llustraton of th DVQL-W (Dgtal Vdo Qualty Lvl Wghtd) mtrc progrss whl fadng causs nar clff-off ffct (loss of th DVB-T srvc avalablty). Fg. 6. Modulaton rror rat (MER) from th constllaton of th DVB-T wth 64-QAM modulaton, varous typs of th transmsson channls and dffrnt C/ rato n th transmsson channl. 5. Dgtal Vdo Qualty Evaluaton Th dgtal pctur analyzr R&S DVQ oprats n accordanc to SSCQE (Sngl Stmulus Contnuous Qualty Evaluaton) mthod [6]. Snc th DCT rlatd artfacts of a comprssd vdo frams ar always assocatd wth blockng, SSCQE dgtal pctur qualty analyzr attmpts to vrfy th xstnc of ths blockng n th pctur. Ths smpl analyss of th pxl ampltud dffrncs maks t possbl to vrfy th xstnc of blockng structurs n comprssd or wth dstorton affctd dgtal vdo frams. Th tst procdur dals wth th dffrncs btwn adjonng pxls wthn a macroblock ar formd. Pxl dffrnc mans that smply th ampltud valus of adjacnt pxls of th Y sgnal wthn a macroblock, and also sparatly thos of th Cb and Cr sgnals ar subtractd. Th pxl dffrncs of all macroblocks wthn a ln ar combnd by addng thm pr ln and fram. Ths fnally provds nformaton about th man pxl dffrnc n th horzontal and vrtcal drcton of th fram wthn all macroblocks. Th sam procss s rpatd for Cb and Cr, th color dffrnc sgnals (dtals n []). Th comparson of pxl dffrncs n a vdo squnc wth a good pctur qualty and n on wth a poor pctur qualty lads to th DVQL-W (Dgtal Vdo Qualty Lvl - Wghtd) objctv qualty valuaton [6]. Fg. 8. Workplac for DVB-T laboratory transmsson: transmttr TX (R&S SFU), masurng rcvr RX1 (Kathrn MSK33), and control rcvr RX (st-top box Humax F3-FOX T), MPEG- dgtal vdo qualty analyzr (R&S DVQ). 6. Rsults Th analyss of th transmsson va Gaussan channl (s Fg. 4 and Fg. 5 for th AWG rfrnc) lads to C/ qual to 17.8 db to achv BER aftr Vtrb on QEF bordr. Accordng to MER (modulaton rror-rat) valuatd from th constllaton analyss C/ s qual to 19.7 db. In Gaussan channl th mparmnts ar only by th man of addtv nos and rsults of MER ar qual to S/ rato n db. Th dffrnc btwn C/ and S/ n th 8k mod s drctly.33 db du to th payload subcarrrs powr vrsus all subcarrrs powr of th OFDM multplx (zro, payload, scattrd, fxd, TPS). Practcal rsults for statonary rcpton of th C/ ar btwn 18 and db. Th valuatd pctur qualty basd on DVQL-W mtrc

7 1 T. KRATOCHVÍL, R. ŠTUKAVEC, DVB-T DIGITAL TERRESTRIAL TELEVISIO TRASMISSIO OVER FADIG CHAELS ndcats th vsbl rrors ( blocknss or blockng, so calld brck wall ffct) n th pctur wth th C/ qual to 19 db or lowr. Ths mtrc ndcats th rcpton vry clos to th clff-off (so calld fall of th clff ) ffct whn th DVB-T srvc s suddnly unavalabl. Th analyss of th transmsson va (s Fg. 4) lads to mnmal C/ qual to 19.1 db to achv BER aftr Vtrb on QEF bordr. Accordng to MER t s qual to 19.7 db. Th dffrnc btwn th thortcal and smulatd valu and th practcal rsult of th mnmal C/ s. db. Th valuatd pctur qualty basd on DVQL-W mtrc ndcats th vsbl rrors n th pctur wth th C/ qual to db or lowr. Th clffoff ffct coms wth th C/ qual to db or lss n th transmsson channl. Th numbr of paths (6, 1 or cho paths) has a mnmal ffct on th achvd BER, MER and DVQL-W. Th analyss of th transmsson va Raylgh channl (s Fg. 5) lads to mnmal C/ btwn 1.1 to 3.3 db to achv BER aftr Vtrb on QEF bordr. Th numbr of analyzd chos has. db nfluncs on mnmal C/ for QEF. Accordng to MER t s btwn 19.6 and 3.3 db. Th dffrnc btwn th thortcal and smulatd valu and th practcal rsult of th mnmal C/ s btwn 1.8 db (6 cho paths) and 4. db ( cho paths). Th valuatd pctur qualty basd on DVQL-W mtrc ndcats th vsbl rrors n th pctur wth th C/ qual to 8 db or lowr. Th clff-off ffct coms wth th C/ qual to 3 db or lss n th transmsson channl. An ncrasng numbr of Raylgh channl paths has approx. 1 db nflunc on clff-off wth lowr numbr of th paths. Th nflunc of th fadng on DVB-T wth 64-QAM constllaton s vdnt (s Fg. 6). A lssr C/ rato lads to a lowr MER n db. A lowr MER valu s ndcatd wth a hghr constllaton sprad ovr modulaton sgnals plan. Exampls of th DVQL-W mtrc valuaton and typcal blockng artfacts n DVB-T transmsson and MPEG- vdo frams ar llustratd (s Fg. 7). 7. Concluson All th transmsson xprmnts wr ralzd for th DVB-T systm paramtrs that wr st n th Transton Tchncal Plan to th DTT broadcastng prsntd by th Czch Tlcommuncaton Offc (CTU) to th Govrnmnt of th Czch Rpublc n 8 (64-QAM, 8k mod, convolutonal cod /3, GI 1/8, non-hrarchcal). DVB-T broadcastng plot projcts n th Czch Rpublc startd n and rgular broadcastng was launchd n 5 wth on so-calld multplx (fv programs, SDTV, MPEG-). In th sprng of 8 th DVB-T srvc covrag ncludd svn transmttrs n fv locatons and SF ntwork (48% populaton). Thr s a plan for nxt four SF ntworks and ASO (analogu TV swtch-off) s plannd n th autumn of 11. Th prsntd rsults can b usd for th transmsson dstortons analyss and valuaton of th DVB-T systm paramtrs nflunc on transmttd sgnal n SF ntwork wth multpath rcpton, chos and SF co-channls. Acknowldgmnts Ths papr was supportd by th Rsarch programm of th Brno Unvrsty of Tchnology no. MSM163513, Elctronc Communcaton Systms and w Gnraton Tchnology (ELKOM), grant projcts of th Czch Scnc Foundaton no. 1/8/P95, Analyss and Smulaton of th Transmsson Dstortons of th Dgtal Tlvson DVB-T/H, and th grant projct no. 1/8/H7 Advancd Mthods, Structurs and Componnts of Elctronc Wrlss Communcaton. Rfrncs [1] REIMERS, U. Dgtal Vdo Broadcastng, Th Famly of Intrnatonal Standards for Dgtal Tlvson. nd d. Brln: Sprngr Vrlag, 4. ISB X. [] FISHER, W. Dgtal Tlvson. A Practcal Gud for Engnrs. 1 st d. w York: Sprngr-Vrlag, 4. ISB [3] ETSI E V1.4.1 (1-1). Europan Standard. Dgtal Vdo Broadcastng (DVB); Framng structur, channl codng and modulaton for DTT. ETSI, 1. [4] ETSI TR 11 9 V1..1 (1-5). Tchncal rport. Dgtal Vdo Broadcastng (DVB); Masurmnt gudlns for DVB systms. ETSI, 1. [5] Rohd & Schwarz. Opratng Manual. Broadcast Tst Systm R&S SFU. Modl Rohd&Schwarz, 5. [6] Rohd & Schwarz. Opratng Manual. Dgtal Vdo Qualty Analyzr R&S DVQ. Modl Rohd&Schwarz, 5. About Authors... Tomáš KRATOCHVÍL was born n Brno, n H rcvd th M.Sc. dgr n 1999 and Ph.D. dgr n 6 n Elctroncs and Communcatons from th Brno Unvrsty of Tchnology. H s currntly assstant profssor at th Dpartmnt of Rado Elctroncs, Brno Unvrsty of Tchnology. Hs rsarch ntrsts nclud dgtal tlvson broadcastng and vdo transmsson, modlng of th transmsson through th transmsson channl modls and vdo and audo tchnqu ara. H s an IEEE mmbr. Radm ŠTUKAVEC was born n Přrov, n H rcvd th M.Sc. dgr n 7 n Elctroncs and Communcatons from th Brno Unvrsty of Tchnology. H s currntly Ph.D. studnt at th Dpartmnt of Rado Elctroncs, Brno Unvrsty of Tchnology. Hs rsarch ntrsts and thss dal wth th DVB-T transmsson and ts dstortons analyss.