Messages
Chapter 5
WAAS GUS Signal Generator User Guide Rev 1
31
Table 18: L5 Initialization Command Fields 500 SPS
SYMBOL RATE FIELD/RF CONFIGURATION FIELD
The message symbol rate sets the Symbols per Second (SPS) bit. When 0, the symbol rate is 500 SPS. When 1, the
symbol rate is 1000 SPS (not currently supported
—
reserved for future use).
The RF Center frequency is set by the RF Center bit. When 0, the default RF frequency is chosen (1227.6 MHz for
L1 and 1176.45 MHz for L5). When 1, the alternate frequency is chosen (1575.42 MHz for L1 and 1227.6 MHz for
L5).
Table 19: Symbol Rate/RF Configuration Field
Byte [15:16]
Q coder init G2.
Byte[15] = init bits 0-7
Byte[16] = init bits 8-9
G2(Q) channel coder
initialization value at zero chip
Count. Set to zero if not used.
Byte Position
Description
Valid Range
Value / Scale Factor
Byte [7]
Symbol Rate/RF
Configuration
0 or 128
Set to zero ‘0’
Byte [8]
Sub-Chip
0 – 255
Initial Sub-Chip Load
Byte [9:10]
Code Chip Advance
0 – 10229
Initial Code Chip Advance
Byte [11:12]
Symbol Advance
and Symbol 1 ms epoch
Bits [0:14] = 0 – 499
Bit [15:15] = 0-1 (MSB)
Initial Symbol Advance
and Symbol 1 ms epoch
Byte [13:14]
I coder init XB(I).
Byte[13] = init bits 0-7
Byte[14] = init bits 8-12
XB(I) I channel coder
initialization value at zero
chip count.
Byte [15:16]
Q coder init XB(Q).
Byte[15] = init bits 0-7
Byte[16] = init bits 8-12
XB(Q) Q channel coder
initialization value at zero
chip count.
Byte [7]
D7
D6
D5
D4
D3
D2
D1
D0
MSB
LSB
RF
Center
SPS
Byte Position
Description
Valid Range
Value / Scale Factor
