Toshiba GD-1221, GD-1220 service manual Trn, Alt

Models: GD-1220 GD-1221

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-Equalizer and echo canceller training (Phase 3)

Training (adjustment) is performed according to the parameters set in the phase 2 to optimize the filters such as an equalizer.

Transmitter

Signal name

Abbreviation

Function

 

 

Remarks

 

 

 

 

 

 

 

 

 

S signal

 

S

Short training

 

 

is a signal made as the

S

 

 

 

 

 

 

 

 

result of phase transition of S.

 

 

 

 

 

 

 

 

 

S signal

 

S

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PP signal

PP

Used by the modem of the

 

 

 

 

 

 

 

 

 

receiver to train the equalizer.

 

 

 

 

 

 

 

 

 

TRN signal

TRN

Used by the receiver to deter-

 

 

 

 

 

 

 

 

 

mine the transmission rate.

 

 

 

 

 

 

 

 

 

 

 

 

 

-Final training (Phase 4)

The settings such as the maximum value for the data rate, selection of the trellis encoder, and data rate which can be supported are made in this phase.

Transmitter/receiver

Signal name

Abbreviation

Function

Remarks

 

 

 

 

PPh signal

PPh

Used by the modem of the

 

 

 

other side to train the equal-

 

 

 

izer.

 

 

 

 

 

ALT signal

ALT

-

 

 

 

 

 

Modulation parameter

MPh

Informs the parameters used

 

 

 

for the image transmission

 

 

 

such as maximum data signal

 

 

 

rate and type of the trellis cod-

 

 

 

ing/pre-coding.

 

 

 

 

 

E sequence

E

-

20 bit sequence of “1”s in

 

 

 

binary

 

 

 

 

GD-1220/1221

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Toshiba GD-1221, GD-1220 service manual Trn, Alt