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Diffstat (limited to 'docs/doxygen/other/ofdm.dox')
| -rw-r--r-- | docs/doxygen/other/ofdm.dox | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/docs/doxygen/other/ofdm.dox b/docs/doxygen/other/ofdm.dox index 62efa0cce5..9a3a18fab8 100644 --- a/docs/doxygen/other/ofdm.dox +++ b/docs/doxygen/other/ofdm.dox @@ -1,6 +1,6 @@ /*! \page page_ofdm OFDM -\section intro Introduction +\section ofdm_introduction Introduction GNU Radio provides some blocks to transmit and receive OFDM-modulated signals. In the following, we assume the reader is familiar with OFDM and how it works, @@ -15,9 +15,9 @@ very little friction. \ref page_packet_data has an example of how to use OFDM in a packet-based receiver. -\section conventions Conventions and Notations +\section ofdm_conventions Conventions and Notations -\subsection fftshift FFT Shifting +\subsection ofdm_fftshift FFT Shifting In all cases where OFDM symbols are passed between blocks, the default behaviour is to FFT-Shift these symbols, i.e. that the DC carrier is in the middle (to be @@ -30,7 +30,7 @@ consistency's sake, this was chosen as a default for all blocks that pass OFDM symbols. Also, when viewing OFDM symbols, FFT-shifted symbols are in their natural order, i.e. as they appear in the pass band. -\subsection indexing Carrier Indexing +\subsection ofdm_indexing Carrier Indexing Carriers are always index starting at the DC carrier, which has the index 0 (you usually don't want to occupy this carrier). The carriers right of the @@ -42,7 +42,7 @@ The carriers left of the DC carrier (with lower frequencies) can be indexed equivalent. The advantage of using negative carrier indices is that the FFT length can be changed without changing the carrier indexing. -\subsection carrieralloc Carrier and Symbol Allocation +\subsection ofdm_carrieralloc Carrier and Symbol Allocation Many blocks require knowledge of which carriers are allocated, and whether they carry data or pilot symbols. GNU Radio blocks uses three objects for this, typically @@ -81,12 +81,12 @@ Note that \p pilot_symbols is longer than \p pilot_carriers in this example-- this is valid, the symbols in \p pilot_symbols[2] will be mapped according to \p pilot_carriers[0]. -\section detectsync Detection and Synchronisation +\section ofdm_detectsync Detection and Synchronisation Before anything happens, an OFDM frame must be detected, the beginning of OFDM symbols must be identified, and frequency offset must be estimated. -\section tx Transmitting +\section ofdm_tx Transmitting \image html ofdm_tx_core.png "Core elements of an OFDM transmitter" @@ -110,7 +110,7 @@ Finally, the cyclic prefix is added to the OFDM symbols. The gr::digital::ofdm_c can also perform pulse shaping on the OFDM symbols (raised cosine flanks in the time domain). -\section rx Receiving +\section ofdm_rx Receiving On the receiver side, some more effort is necessary. The following flow graph assumes that the input starts at the beginning of an OFDM frame and is prepended |