Quasonix TIMTER Installation And Operation Manual page 83

The IRIG standard calls out six variants of LDPC codes—all combinations of two different information block sizes
(k=4096 bits and k=1024 bits) and three different code rates (r=1/2, r=2/3, and r=4/5).
With the LD6 option, use LD 0 or 1 to disable or enable LDPC, then use 0-5 to indicate the desired LDPC code. A
space is required between the disable/enable code and the desired LDPC selection, as shown in the examples.
Examples:
LD 0 Disable the LDPC encoder
LD 1 0 Enable the LDPC encoder and set the block size and code rate to k=4096, r=1/2
LD 1 1 Enable the LDPC encoder and set the block size and code rate to k=1024, r=1/2
LD 1 2 Enable the LDPC encoder and set the block size and code rate to k=4096, r=2/3
LD 1 3 Enable the LDPC encoder and set the block size and code rate to k=1024, r=2/3
LD 1 4 Enable the LDPC encoder and set the block size and code rate to k=4096, r=4/5
LD 1 5 Enable the LDPC encoder and set the block size and code rate to k=1024, r=4/5
4.2.3.1.12 NRZ-M Conversion – MC
MC enables selection of available PCM encoding values. The encoding values are as follows:
0 NRZ-L: Non-return-to-zero, level
1 NRZ-M: Non-return-to-zero, mark
2 NRZ-S: Non-return-to-zero, space
3 Biphase-S: Biϕ, space
4 DM-M: Delay modulation (Miller code), mark
5 DM-S: Delay modulation (Miller code), space
MC options, other than 0 (Off), are forms of differential encoding, so they are not used with LDPC, STC, or DE On.
They are typically only used with PCM/FM or legacy PSK modes.
75 Quasonix, Inc.
LD6 Code Block Size and Code Rate
0
1
2
3
4
5
6
7
8
9
10 M2-S: Delay modified modulation (Miller squared
TIMTER™ Multi-mode Dual
Telemetry Transmitter
k=4096, r=1/2
k=1024, r=1/2
k=4096, r=2/3
k=1024, r=2/3
k=4096, r=4/5
k=1024, r=4/5
RZ: Return-to-zero
Biphase-L: Biϕ, level
Biphase-M: Biϕ, mark
M2-M: Modified delay modulation (Miller squared
code), mark
code), space