MC92314 View Datasheet(PDF) - Motorola => Freescale

Part Name

Description

Manufacturer

MC92314

DVB-T Single Chip Demodulator Application Note

Motorola => Freescale 

System Overview

Freescale Semiconductor, Inc.

Key items of the FEC part include:

• Maximum 37 Mbit/s output rate.

• 3 Bit soft-decision input matched to the output of the OFDM block.

• Code rate 1/2 and depunctured rates of 2/3, 3/4, 5/6, and 7/8.

• Automatic or manual rate selection.

• Viterbi decoder survivor depth 96

• Signal quality output data.

• DVB compliant 12 x 17 Forney Convolutional Deinterleaver

• Reed-Solomon (204, 188, 8) decoder as specified by DVB

• DVB Descrambler for Energy Dispersal & inverted Sync Byte removal

n • Bit Error Rate (BER) and uncorrectable Frame Error (BAD) monitoring

tio • setting of “transport_error_indicator” bit in the MPEG2 output stream (MSB of first byte

immediately following the Sync Byte)

a 1.2 Considerations on Terrestrial Transmission

rm One of the most important aspects in designing a transmission system is to chose the modulation

fo scheme that fits best to the characteristics of the transmission channel employed. Comparing the

In terrestrial channel in the UHF band with the channels of the satellite or cable system yields

several important differences that exclude the modulation schemes used there from an efficient

y usage in the terrestrial channel.

ar 1.2.1 Echoes on the Transmission Path

in In Figure 1-1 a typical environment for terrestrial reception is given. The antenna of the stationary

lim receiver receives the signal belonging to the direct path from the transmitter as well as delayed

echoes e.g. from buildings (this is called a Ricean channel). In contrast to this a portable receiver

e may receive only echoes without a signal direct from the transmitter (Rayleigh channel

Pr characteristics).

MOTOROLA

1-2

Single Chip DVB-T Demodulator - Rev. 1.3 (11/30/98)

For More Information On This Product,

Go to: www.freescale.com

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