diff options
| -rw-r--r-- | gr-trellis/src/lib/fsm.h | 100 |
1 files changed, 98 insertions, 2 deletions
diff --git a/gr-trellis/src/lib/fsm.h b/gr-trellis/src/lib/fsm.h index 0a90b2cd3..e5f717af0 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); }; |