Introduction This application note describes the VSB-ENC-150E 8-VSB Modulator and its applications.

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1 Applicatin Nte 8-VSB Mdulatr Mdel Number: VSB-ENC-150E Intrductin This applicatin nte describes the VSB-ENC-150E 8-VSB Mdulatr and its applicatins. Prduct Descriptin The VSB-ENC-150E is an 8-VSB Mdulatr. The unit accepts either SMPTE-310M r DVB-ASI signals as its input, mdulates it int an 8-VSB 44.0 MHz IF signal, and utputs an RF 8-VSB signal between the frequency range f 55 t 858 MHz. The main features f the VSB-ENC-150E are as fllws: MHz Frequency Agile in 12.5 KHz steps Cvers the UHF/VHF and CATV Frequency Range RF Pwer level adjustment frm +50 dbmv t +62 dbmv Accepts SMPTE-310M r DVB-ASI Inputs RF, SMPTE-310M and (2) DVB-ASI Outputs Frnt Panel Test Pints: 44.0 MHz IF Out and DVB-ASI Out PSIP VCT User Mdificatin Majr Channel # Minr Channel # Statin ID Transprt Stream ID Channel Transprt Stream ID Stres TX VCT User Mdified Parameters Perfrms PCR Crrectin and Null Packet Insertin/Deletin with fixed utput rate at Mbps Bypass mde t skip PCR Crrectin and Null Packet Insertin Lss f Transprt Stream Alarm RS232 and Frnt Panel Cntrl 1U Rack Muntable 1

2 Functinal Blck Diagram The signal flw thrugh the VSB-ENC-150E is shwn belw in Figure 1. Figure 1: VSB-ENC-150E Functinal Blck Diagram Serial t Parallel Cnversin The serial SMPTE-310M and DVB-ASI input signals need t be cnverted t parallel MPEG2 Transprt Frmat befre Baseband Prcessing. Nte: The VSB-ENC-150E can accept any DVB-ASI signal that has a rate less than r equal t Mbps. Baseband Prcessing The baseband prcessing includes the Null Packet Insertin r Remval, PCR Crrectin and PSIP Mdificatin. The first step in the prcess is Null Packet Insertin r Remval. Nte: Baseband Prcessing nly ccurs fr DVB-ASI Inputs less than r equal t 45 Mbps. If SMPTE-310M and DVB-ASI utputs are desired, the DVB-ASI Input shuld nt exceed 45 Mbps. The Null Packet Insertin/Remval des the fllwing: Figure 2: Null Packet Insertin/Remval When the MPEG2 Transprt Stream is greater than Mbps, the null packets in the stream are remved befre entering the FIFO. When the MPEG2 Transprt Stream utput f the FIFO is less than Mbps, null packets are inserted int the MPEG2 Transprt Stream t bring the rate back up t Mbps. The secnd step is PCR Crrectin. The Prgram Clck Reference (PCR), embedded within the transprt stream, is used t synchrnize a receiver s clck with an encder s clck. The riginal PCR values that were stamped int the stream by the riginal encder will nt be the crrect PCR values fr the receiver after null packets are inserted int r deleted frm the stream. Therefre the PCR values need t be re-stamped s that the receiver will have the crrect PCR values, thus aviding PCR clck jitter at the receiver end. The final step is the PSIP mdificatin where the VCT s STID, Majr & Minr Channel Numbers are mdified within the stream. 2

3 Parallel t Serial Cnversin After baseband prcessing, the parallel MPEG2 Transprt Frmat is cnverted back t serial fr SMPTE-310M r DVB-ASI Outputs. SMPTE-310M encding als ccurs here. Nte: The DVB-ASI utput will be at Mbps. 8-VSB Mdulatr The 8-VSB Mdulatr mdulates the Parallel MPEG2 Transprt Stream int an 8-VSB 44.0 MHz IF signal. Upcnverter The Upcnverter takes 44.0 MHz IF signal and cnverts it up t a higher frequency. It s RF utput is frequency agile in 12.5 KHz steps ver a range f 55 MHz t 858 MHz. These frequencies cver bth the CATV and VHF/UHF bands. Frnt and Back Panel Descriptins The frnt panel f the VSB-ENC-150E is shwn belw in Figure 2. Figure 2: Frnt Panel f the VSB-ENC-150E Signal DVB-ASI Output Testpint 44.0 MHz IF Output Testpint The back panel f the VSB-ENC-150E is shwn belw in Figure 3. Figure 3: Back Panel f the VSB-ENC-150E Signal DVB-ASI Output #1 DVB-ASI Output #2 DVB-ASI Input SMPTE-310M Output RS232 Alarm SMPTE-310M Input RF Output DSUB 9 Scket 3 terminal Phenix 75Ω F 3

4 Specificatins General Descriptin Range Units AC Pwer Frequency Hz Vltage VAC Current 1.2 Amp (max) Operating Cnditins Temperature 0-50 C Altitude 12,000 ft (max) Humidity (nn-cndensing) 95 % Materials Aluminum chassis Weight Net 10 lbs. Grss (shipping) 13 lbs. Dimensins Height 1.75 inches (1RU) Width 19 inches Depth 18 inches Cling Blwer Lcated n the left side twards the back f the unit SMPTE310M Serial Interface (Baseband Data Input/Output) Parameter Specificatin Cmments Surce Impedance 75 hms Output Cupling AC AC inductively cupled Signal Oversht <10% Data Frmat Biphase Mark Cding Transprt Stream Bit Rate Mbps Raw serial data rate ± 2.8 ppm DVB-ASI Serial Interface (Baseband Data Input/Output) Parameter Specificatin Cmments Surce Impedance 75 hms Output Cupling AC AC inductively cupled Transprt Stream Bit Rate (input) 2.6 Mbps Min 45 Mbps Max Transprt Stream Bit-Rate (utput) Mbps PSIP Update Parameter Specificatin Cmments Statin Identificatin Up t seven letters Majr Channel Number # Minr Channel Number # 0-9 Transprt Stream ID Channel TSID

5 RF Output Descriptin Specificatin Cnditin Frequency Range MHz band center Frequency Step Size 12.5 KHz Frequency Accuracy <±2 ppm at 23ºC Frequency Stability <±2 ppm Aging <±1 ppm/year RF Output Level +50 t +62 dbmv RF Output Level Step Size 1 dbmv Impedance 75 hm F Spurius -60 dbc including harmnics Return Lss >16 db Ordering Infrmatin Part Number VSB-ENC-150E Descriptin 8-VSB Mdulatr with RF Output Additinal Infrmatin at KTech Web Site: Fr Pricing and Delivery infrmatin: sales@ktechtelecm.cm KTech Telecmmunicatins, Inc. DTV Bradcast and Cable Prducts Prairie St., Unit B Chatswrth, CA Phne (818) Fax (818)