R&S SMJ100A, Operating Manual

Page: 346 / 874

Instrument Function
R&S
®
SMJ100A
330 Operating Manual 1403.7458.32 ─ 14
MSK
1 bit per symbol, FSK deviation
SOUR:BB:DM:FORM MSK
SOUR:BB:DM:FSK:DEV 0.1 MHz
2FSK
1 bit per symbol
SOUR:BB:DM:FORM FSK2
4FSK
2 bit per symbol
SOUR:BB:DM:FORM FSK4
In addition to the FSK modulations, a variable FSK modulation with definable deviation
per symbol is available.
[:SOURce<hw>]:BB:DM:FORMat
on page 649
User Mapping
A user defined modulation mapping file can also be selected as modulation mapping
source. The user modulation mapping file must have extension
*.vam
and can be cre-
ated with the R&S mapping wizard. The mapping wizard (mapwiz) is a tool from Rohde
& Schwarz designed for editing modulation schemes (e.g. QPSK, 32QAM). Its main
purpose is the assignment of logical symbol numbers to constellation points and the
selection of modulation specific parameters. Beyond this it supports the creation of
nearly any arbitrarily chosen constellation diagram. The output of mapwiz is a mapping
file (
*.vam
) that can be imported on a R&S SMJ. The program was developed on a
32-bit Microsoft Windows platform under MATLAB. For more information, refer to the
description "Introduction to "mapwiz" Mapping Editor" on the Rohde&Schwarz Internet
page.
5.8.2.3 Coding - Custom Digital Mod
Modulation symbols are coded directly before I and Q values or frequency shifts are
assigned. Coding is thus directly related to modulation methods, which is the reason
why codings are not freely combinable with modulation methods. The following table
shows which of the coding combinations are available and defines the modulation
types for which the various coding procedures can be used.
In the notation used below an denotes the n-th input symbol and bn denotes the corre-
spondingly coded output symbol. Individual bits in the symbols from the LSB (least sig-
nificant bit) to the MSB (most significant bit) are denoted by a0n, a1n and so on. The
same applies to the output symbols.
Baseband Signal - Baseband Block