GC5318 Datasheet, PDF (10/45 Pages) Texas Instruments – HIGH-DENSITY DIGITAL UPCONVERTER

GC5318
HIGH-DENSITY DIGITAL UPCONVERTER
SLWS187 – JULY 2006
www.ti.com
When diversity channels are employed, a counter in the synchronization block toggles the sign of the gain
value in a prescribed fashion. The UMTS frame starts with positive gain for 256 chips, then toggles to
negative gain for 512 chips, then toggles again to positive gain for 512 chips, and so on until the end of
the frame. The last 256 chips of the frame are negative gain. This sequence repeats for subsequent
frames.
Table 2-4. Programming
VARIABLE
pilot_psc(15:0)
pilot_psc(17:16)
pilot_diversity
pilot_delay(15:0)
pilot_gain_0(15:0)
pilot_gain_1(15:0)
ssel_pilot(2:0)
DESCRIPTION
Lower 16 bits of the 18-bit pilot LFSR initial sequence.
Upper two bits of the 18-bit pilot LFSR initial sequence.
Sets main or diversity pilot generation. 0 = main, 1 = diversity
Unsigned delay value (in chips) from sync event. 0 to 38399 chips.
Gain value. pilot_gain_0 and pilot_gain_1 must be set to the same value for proper operation. Must be set to 0 for
CDMA operation.
Gain value. pilot_gain_0 and pilot_gain_1 must be set to the same value for proper operation. Must be set to 0 for
CDMA operation.
Sync source
2.1.4 RMS Power Meter
18
I
Top
37
Integrate
32
50 Bits
Register
32
RMS Power
Q ¹⁸
Clear
Transfer
pmeter_sync_delay_duc pmeter_interval_duc
7
9
Sync
Sync Delay
Counter
7 Bits
(in samples)
Interval
Counter
9 Bits
(in increments
of 64 samples)
pmeter_integration_duc
13
Integration Period Counter
13 Bits
(increments in samples)
Interrupt
Power Measurement Time Line
Interrupt
Sync Delay
Integration Time
Interval Time
Interrupt
Integration Time
Interval Time
Interrupt
Integration Time
Time
Sync
Event
Integration
Start
Integration
Start
Integration
Start
Figure 2-7. RMS Power Meter
10
GC5318 Operation