OFDM Transmitter

Hierarchical block for OFDM modulation.

The input is a byte stream (unsigned char) and the output is the complex modulated signal at baseband.

Parameters

 * FFT Length
 * The length of FFT (integer).


 * Cyclic Prefix Length
 * The length of cyclic prefix in total samples (integer).


 * Packet Length Tag Key
 * The name of the tag giving packet length at the input.


 * Occupied Carriers
 * A vector of vectors describing which OFDM carriers are occupied.


 * Pilot Carriers
 * A vector of vectors describing which OFDM carriers are occupied with pilot symbols.


 * Pilot Symbols
 * The pilot symbols.


 * Sync Word 1
 * The first sync preamble symbol. This has to be with zeros on alternating carriers. Used for fine and coarse frequency offset and timing estimation.


 * Sync Word 2
 * The second sync preamble symbol. This has to be filled entirely. Also used for coarse frequency offset and channel estimation.


 * Header Modulation


 * Payload Modulation


 * Rolloff length (samples)
 * The rolloff length in samples. Must be smaller than the CP.


 * Scramble Bits
 * Activates the scramblers (set this to True unless debugging)


 * Log Debug Info
 * Write output into log files (Warning: creates lots of data!)

Example Flowgraph
This flowgraph can be found at https://github.com/gnuradio/gnuradio/blob/master/gr-digital/examples/ofdm/ofdm_loopback.grc



Source Files

 * Python files
 * 


 * Block definition
 *