GC5316_14 Datasheet, PDF (31/76 Pages) Texas Instruments – HIGH-DENSITY DIGITAL DOWNCONVERTER AND UPCONVERTER

www.ti.com
GC5316
SLWS154A − JANUARY 2004 − REVISED MARCH 2004
Table 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 2 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
3.1.4 Transmit Channel RMS Power Meter
18
I
Top
37 _Integrate 32
32
Re gis te r
RMS Power
50 bits
18
Q
Cle a r
pmeter_interval_duc
pme t e r_ sy nc_ de la y _ duc
7
9
Tra ns fe r
pmeter_integration_duc
13
Sync
Sync D elay
C ounter
7 Bits
(in samples)
I nterval
Counter
9 Bits
(in increments of
64 samples)
Integration Period Counter
13 Bits
(in increments of 4 samples)
Inte rrupt
Power Measurement Time Line
Sync Delay
Integration Time
Interrupt
Integration Time
Interrupt
Integration Time
Interval Time
Interval Time
Interrupt
Time
Sync
Event
I ntegration
Sta rt
I ntegration
Sta rt
I nte grat ion
Sta rt
Figure 26. Transmit Channel RMS Power Meter
Each transmit channel includes an RMS power meter used to measure the RMS power within the channel.
Functionally, the power meter block is identical to the RMS power meter blocks used in the receive chain.
The power meter samples the I and Q data stream before the PFIR filter. Both 18-bit I and Q data are squared,
summed, and then integrated over a time determined by pmeter_integration_duc (13 bits). Integration time = 4 x
pmeter_integration_duc + 1 (in units of a sample period or generally a chip period).
There is a programmable 9-bit interval counter which sets the interval over which power measurements are repeated.
The timer counts in increments of 64 samples. The interval time = 64(pmeter_interval_duc+1) The interval time must
be greater than (not equal to) the integration time.
31