CRC-DabMod is the DAB OFDM modulator command developed by Communication Research Center (CRC) from Canada. It is now published in open source with a gnu GPLv3 license.
- CRC-DabMod description and source code on MMBTools website
Resampling is the cause of high CPU usage but cannot be avoided to match with USRP sampling limitation. One possiblity could be to change the clock of the USRP1.
CRC-DabMod ./racor.eti -l -g1 -r3200000
get racor.eti file, perform OFDM modulation on baseband at a sampling frequency of 3.2MHz. Output is sent to the standard output if not redirected or piped to another command (CRC-Dwap.py in general)
When building from the source code, be careful to disable debugging, otherwise there will be lot of wasted CPU usage:
./configure --with-debug-malloc=no --disable-debug
CRC-DabMod [input [output]] [-c clockrate] [-f] [-g gainMode] [-h] [-r samplingRate]
input: ETI input filename (default: stdin). output: COFDM output filename (default: stdout). -c: Set the DAC clock rate. -f: (deprecated) Set fifo input. -g: Set computation gain mode: 0 FIX, 1 MAX, 2 VAR -h: Print this help. -l: Loop file when reach end of file. -r: Set output sampling rate (default: 2048000).