DESCRIPTION
Designed for the fast growing direct broadcast satellite (DBS) digital TV receiver market, the SGS-THOMSON STV0196B Digital Satellite Receiver Front-end integrates all the functions needed to demodulate incoming digital satellite TV signals from the tuner : Nyquistfilters, QPSK/BPSK demodulator, signal power estimator, automatic gain control, Viterbi decoder, deinterleaver, ReedSolomon decoder and energy dispersal descrambler. This high level of integration greatly reduces the package count and cost of a set top box.
FRONT-END INTERFACE
.I AND Q 6 BITS DIGITAL INPUTS AT 2Fs
.QPSK DEMODULATION (Two Modes : A and B)
.INPUT SYMBOL FREQUENCY (Fs) UP TO 30MSYMBOLS/S
.DIGITAL NYQUIST ROOT FILTER : ROLL-OFF VALUE OF 0.35 IN MODE A
.DIGITAL CARRIER LOOP :
- ON-CHIP DEROTATOR AND TRACKING LOOP
- CARRIER OFFSET INDICATOR
- LOCK DETECTOR
- C/N INDICATOR FOR DISH POSITIONING .DIGITAL TIMING RECOVERY :
- INTERNAL TIMING ERROR EVALUATION AND FILTER
- OUTPUT CONTROL SIGNAL FOR A 2Fs EXTERNAL VCO OR VCXO .DIGITAL AGC :
- INTERNAL SIGNAL POWER ESTIMATION AND FILTER
- OUTPUT CONTROL SIGNAL FOR AGC (1 BIT PULSE DENSITY MODULATION)
FORWARD ERROR CORRECTION
.INNER DECODER :
- VITERBI SOFT DECODER FOR CONVOLUTIONAL CODES, CONSTRAINT LENGTH M = 7, RATE 1/2
- PUNCTURED CODES 1/2, 2/3, 3/4, 5/6 AND 7/8 IN MODE A
- AUTOMATIC OR MANUAL RATE AND PHASE RECOGNITION
.DEINTERLEAVER :
- WORD SYNCHRO EXTRACTION
- CONVOLUTIVE DEINTERLEAVER
.OUTER DECODER :
- IN MODE A : REED-SOLOMON DECODER FOR 16 PARITY BYTES ; CORRECTION OF UP TO 8 BYTE ERRORS
- BLOCK LENGTHS : 204 IN MODE A
- ENERGY DISPERSAL DESCRAMBLER CONTROL
.I2C SERIAL BUS