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