Chapter 7
161
Custom Real Time I/Q Baseband
Working with Differential Data Encoding
symbols can be differentially encoded during the modulation process by assigning symbol table offset values
associated with each data value.
Figure 7-3
shows the 4QAM modulation in the
I/Q Values
editor.
Figure 7-3
NOTE
The number of bits per symbol can be expressed using the following formula. Because the
equation is a ceiling function, if the value of x contains a fraction, x is rounded up to the
next whole number.
Where x = bits per symbol, and y = the number of differential states.
The following illustration shows a 4QAM modulation I/Q State Map.
1
2
3
4
1st Symbol
Data = 00000000
Distinct values: +1, +1
4th Symbol
Data = 00000011
Distinct values: +1, -1
2nd Symbol
Data = 00000001
Distinct values: -1, +1
3rd Symbol
Data = 00000010
Distinct values: -1, -1
Summary of Contents for E8247C
Page 10: ...Contents x ...
Page 96: ...86 Chapter 4 Analog Modulation Configuring the LF Output ...
Page 142: ...132 Chapter 6 Custom Arb Waveform Generator Working with Filters ...
Page 178: ...168 Chapter 7 Custom Real Time I Q Baseband Working with Differential Data Encoding ...
Page 198: ...188 Chapter 10 Troubleshooting ...
Page 214: ...204 Chapter 10 Troubleshooting Returning a Signal Generator to Agilent Technologies ...