GC5018 Datasheet, PDF (16/115 Pages) Texas Instruments – 8-CHANNEL WIDEBAND RECEIVER

GC5018
8-CHANNEL WIDEBAND RECEIVER
SLWS169 – MAY 2005
4 UMTS DDCswith up to 128 tap PFIR
18
18
4 to 2 (complex) or
18
4 to 1 (real) switch
CDMA DDC A
18
Output
Interface
4 to 2 (complex) or
4 to 1 (real) switch
CDMA DDC B
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4 to 2 (complex) or
4 to 1 (real) switch
4 to 2 (complex) or
4 to 1 (real) switch
DDC0
DDC1
CDMA DDC A
or 1 UMTS DDC
CDMA DDC B
Output
Interface
DDC0 plus DDC1
DDC2 plus DDC3
DDC4 plus DDC5
DDC6 plus DDC7
VARIABLE
ddc_ena
cdma_mode
gbl_ddc_write
PROGRAMMING
DESCRIPTION
When set, turns on the DDC.
When set, puts the DDC block in dual channel CDMA mode.
When set, all subsequent programming (writes only) for DDC0 and DDC1 is also written to DDC2/4/6 and DDC3/5/7.
3.2.1 Downconverter Function Blocks
18
from
18
rx_distribution 18
bus
18
4 to 2
Select
Delay
Adjust
Zero
Pad
Six Stage
CIC Filter
Dec 4 to 32
Checksum
Generator
Frequency ³²
Phase ¹⁶
NCO
CFIR
Filter
Dec by 2
PFIR
Filter
Dec by 1
AGC
RMS Power
Measure
Serial
Interface
serial I, Q
up to 18
(25−bits with
AGC disabled)
parallel I, Q
Each GC5018 downconversion block can process two CDMA carriers or a single UMTS carrier. Signal
data is selected from one of four ports for real inputs, or two of four ports for complex inputs. Data from
the selected port(s) is multiplied with a complex, programmable numerically controlled oscillator (NCO)
16
RECEIVE DIGITAL SIGNAL PROCESSING