VP306 datasheet(36/85 Pages) MITEL

36 / 85 page

VP305/6

DRAFT - PRELIMINARY DATA

The duplication or disclosure of data contained on this sheet is subject to the restrictions

on the title page of this document.

2.7. BANK 2: Program QPSK registers.

2.7.1. SCALE: IOUT and QOUT outputs, scale factor register.

Parallel mode -

Bank 2. Address 1.

Type Read / Write.

Serial mode - Address 17.

6543210

SCALE[7:0] Scale factor for IOUT and QOUT outputs

SCALE[7:0]

Scale factor for IOUT and QOUT outputs. The value in the SCALE register adjusts

the matched filter outputs before the signal is truncated to 3 bits. These signals are

output from the QPSK block and fed direct to the Viterbi block.

For an AGC_REF setting of 84, the SCALE value is recommended to be set to 158.

2.7.2. SNR_THS: Signal to noise ratio estimator threshold register.

Parallel mode -

Bank 2. Address 2.

Type Read / Write.

Serial mode - Address 18.

7654

3210

SNR_THS[7:0] SNR estimator threshold

SNR_THS[7:0]

SNR estimator threshold.

The SNR is compared internally to the value set in the SNR_THS register. Fig 14 on

page 38 shows the relationship between the parameter and the Symbol energy to

Noise power ratio (Es / No). A value for SNR_THS of 100 which corresponds to an

Es / No of 11dBs is recommended during tracking mode. After acquisition is

complete, set the SNR_THS value to zero.

Es / No (dB )

100

150

200

250

AGC_REF = 84

Fig. 13 SNR threshold vs. Es / No.

VP306 Datasheet(PDF) 36 Page - Mitel Networks Corporation