judah715 / gr-ccsds

Implementation of CCSDS FEC Stack

CCSDS FEC Codes Stack

This GNU Radio OOT implements CCSDS FEC codes as specified by the CCSDS TM Synchonization and Channel Coding (CCSDS 131.0-B-2, August 2011).

FEC Codes Supported

• CC(7,1/2)
• RS(255,223) and RS(255,239) [Conventional and Dual-basis]
• LDPC(8176,8154) and LDPC(8160,7136) [aka C2]
• Turbo Codes [based on Gianluca's deepspace-turbo module and gr-dslwp]
• Frame sync, with automatic ambiguity resolution

Dependencies

The flowgraphs use the gr-mapper OOT to evaluate BER performance.

git clone https://github.com/gr-vt/gr-mapper.git

mkdir build && cd build

cmake .. && make

sudo make install && sudo ldconfig

Installation

git clone https://github.com/mbkitine/gr-ccsds.git

mkdir build && cd build

cmake .. && make

sudo make install && sudo ldconfig

Usage

See examples folder. Configuration of LDPC Encoder and Decoder

• The LDPC encoder uses circulants to create the generator matrix. The circulant file is under /lib/fec/ldpc/gmini/C2.txt
• The LDPC decoder uses alist file to create the parity check matrix. The alist file is under /lib/fec/ldpc/alist/C2_alist.a

Issues

• Memory leaks in the LDPC Decoder (See examples/LDPC/ldpc_bit_error_rate.grc)
• Memory leaks in the Turbo Decoder (See examples/Turbo/turbo_bit_error_rate.grc)