From d10b330e60e62ff031785d96ec98c455c5c562eb Mon Sep 17 00:00:00 2001
From: Ben Reynwar <ben@reynwar.net>
Date: Sun, 6 Feb 2011 16:39:26 -0700
Subject: Added comments to fsm.h
---
gr-trellis/src/lib/fsm.h | 100 ++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 98 insertions(+), 2 deletions(-)
(limited to 'gr-trellis/src/lib/fsm.h')
diff --git a/gr-trellis/src/lib/fsm.h b/gr-trellis/src/lib/fsm.h
index 0a90b2cd33..e5f717af08 100644
--- a/gr-trellis/src/lib/fsm.h
+++ b/gr-trellis/src/lib/fsm.h
@@ -27,31 +27,114 @@
#include <iosfwd>
/*!
- * \brief FSM class
+ * \brief Finite State Machine Specification class.
+ *
+ * An instance of this class represents a finite state machine specification (FSMS)
+ * rather than the FSM itself. It particular the state of the FSM
+ * is not stored within an instance of this class.
*/
class fsm {
private:
+ // Input alphabet cardinality.
int d_I;
+ // Number of states.
int d_S;
+ // Output alphabet cardinality.
int d_O;
+ // NS means Next State.
+ // next_state = d_NS[current_state * d_I + input_symbol]
std::vector<int> d_NS;
+ // OS means Output Symbol.
+ // output_symbol = d_OS[current_state * d_I + input_symbol]
std::vector<int> d_OS;
+ // PS means Previous State.
std::vector< std::vector<int> > d_PS;
+ // PI means Previous Input Symbol.
+ // d_PS[current_state][k] and d_PI[current_state][k], is a pair of the form
+ // (previous_state, previous_input_symbol) that could have produced the
+ // current state.
std::vector< std::vector<int> > d_PI;
- std::vector<int> d_TMi;
+ // TM means Termination matrix.
+ // d_TMl[s*d_S+es] is the shortest number of steps to get from state s to
+ // state es.
std::vector<int> d_TMl;
+ // d_TMi[s*d_S+es] is the input symbol required to set off on the shortest
+ // path from state s to es.
+ std::vector<int> d_TMi;
void generate_PS_PI ();
void generate_TM ();
bool find_es(int es);
public:
+ /*!
+ * \brief Constructor to create an uninitialized FSMS.
+ */
fsm();
+ /*!
+ * \brief Constructor to copy an FSMS.
+ */
fsm(const fsm &FSM);
+ /*!
+ * \brief Constructor to to create an FSMS.
+ *
+ * \param I The number of possible input symbols.
+ * \param S The number of possible FSM states.
+ * \param O The number of possible output symbols.
+ * \param NS A mapping from (current state, input symbol) to next state.
+ * next_state = NS[current_state * I + input_symbol]
+ * \param OS A mapping from (current state, input symbol) to output symbol.
+ * output_symbol = OS[current_state * I + input_symbol]
+ *
+ */
fsm(int I, int S, int O, const std::vector<int> &NS, const std::vector<int> &OS);
+ /*!
+ * \brief Constructor to create an FSMS from file contents.
+ *
+ * \param name filename
+ *
+ */
fsm(const char *name);
+ /*!
+ * \brief Creates an FSMS from the generator matrix of a (n, k) binary convolutional code.
+ *
+ * \param k ???
+ * \param n ???
+ * \param G ???
+ *
+ */
fsm(int k, int n, const std::vector<int> &G);
+ /*!
+ * \brief Creates an FSMS describing ISI.
+ *
+ * \param mod_size modulation size
+ * \param ch_lenth channel length
+ *
+ */
fsm(int mod_size, int ch_length);
+ /*!
+ * \brief Creates an FSMS describing the trellis for a CPM.
+ *
+ * \param P ???? h=K/P (relatively prime)
+ * \param M alphabet size
+ * \param L pulse duration
+ *
+ * This FSM is based on the paper by B. Rimoldi
+ * "A decomposition approach to CPM", IEEE Trans. Info Theory, March 1988
+ * See also my own notes at http://www.eecs.umich.edu/~anastas/docs/cpm.pdf
+ */
fsm(int P, int M, int L);
+ /*!
+ * \brief Creates an FSMS describing the joint trellis of two FSMs.
+ *
+ * \param fsm1 first FSMS
+ * \param fsm2 second FSMS
+ */
fsm(const fsm &FSM1, const fsm &FSM2);
+ /*!
+ * \brief Creates an FSMS representing n stages through the originial FSM (AKA radix-n FSM).
+ *
+ * \param original FSMS
+ * \param n Number of stages.
+ */
fsm(const fsm &FSM, int n);
int I () const { return d_I; }
int S () const { return d_S; }
@@ -62,7 +145,20 @@ public:
const std::vector< std::vector<int> > & PI () const { return d_PI; }
const std::vector<int> & TMi () const { return d_TMi; }
const std::vector<int> & TMl () const { return d_TMl; }
+ /*!
+ * \brief Creates an svg image of the trellis representation.
+ *
+ * \param filename filename
+ * \param number_stages ????
+ *
+ */
void write_trellis_svg(std::string filename ,int number_stages);
+ /*!
+ * \brief Write the FSMS to a file.
+ *
+ * \param filename filename
+ *
+ */
void write_fsm_txt(std::string filename);
};
--
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