CECCO::Trellis< T >::ListViterbi_Workspace< cost_t > Struct Template Reference

Workspace for list-output Viterbi decoding on this trellis. More...

#include <graphs.hpp>

Public Member Functions
	ListViterbi_Workspace (const Trellis &tr)
	Allocate metric arrays for tr.
void	calculate_edge_costs (const Trellis &tr, const Vector< T > &r)
	Set hard-decision edge costs from received word r.
void	calculate_edge_costs (const Trellis &trellis, const Matrix< double > &llrs)
	Set soft edge costs from symbol-level LLRs.

Public Attributes
std::vector< std::vector< cost_t > >	edge_costs
	Edge cost for each segment and edge index.
std::vector< std::vector< cost_t > >	cost_to_go
	Minimum cost from each vertex (by layer and id) to any final-layer vertex.

Static Public Attributes
static constexpr bool	is_soft = std::is_floating_point_v<cost_t>
	True for floating-point soft metrics.
static constexpr cost_t	init
	Cost of an unreachable vertex or an infeasible path.

Detailed Description

template<FieldType T>
template<typename cost_t>
requires std::integral<cost_t> || std::floating_point<cost_t>
struct CECCO::Trellis< T >::ListViterbi_Workspace< cost_t >

Workspace for list-output Viterbi decoding on this trellis.

Template Parameters

cost_t

Integral type for hard-decision costs or floating-point type for soft costs

Stores edge costs by segment and, for the priority-first path enumeration, the backward cost-to-go from every vertex to the final layer. Construct it from the trellis before calling the list Viterbi routine in codes.hpp.

Definition at line 299 of file graphs.hpp.

Constructor & Destructor Documentation

ListViterbi_Workspace()

template<FieldType T>

template<typename cost_t>

CECCO::Trellis< T >::ListViterbi_Workspace< cost_t >::ListViterbi_Workspace ( const Trellis & tr )

explicit

Allocate metric arrays for tr.

Parameters

tr	Trellis whose layer and edge sizes define the workspace

Definition at line 601 of file graphs.hpp.

Member Function Documentation

calculate_edge_costs() [1/2]

template<FieldType T>
requires std::integral<cost_t>

template<typename cost_t>
requires std::integral<cost_t>

void CECCO::Trellis< T >::ListViterbi_Workspace< cost_t >::calculate_edge_costs	(	const Trellis &	tr,
		const Vector< T > &	r )

Set hard-decision edge costs from received word r.

Parameters

tr	Trellis whose edges define candidate symbols
r	Received word; length must equal the number of segments

Exceptions

std::invalid_argument

if r.get_n() != tr.E.size()

Definition at line 612 of file graphs.hpp.

calculate_edge_costs() [2/2]

template<FieldType T>
requires std::floating_point<cost_t> && FiniteFieldType<T>

template<typename cost_t>
requires std::floating_point<cost_t> && FiniteFieldType<T>

void CECCO::Trellis< T >::ListViterbi_Workspace< cost_t >::calculate_edge_costs	(	const Trellis &	trellis,
		const Matrix< double > &	llrs )

Set soft edge costs from symbol-level LLRs.

Parameters

trellis	Trellis whose edges define candidate symbols
llrs	Symbol-level LLR matrix with q−1 rows and one column per segment

Exceptions

std::invalid_argument

if the LLR matrix has the wrong number of rows or columns

Definition at line 629 of file graphs.hpp.

Member Data Documentation

cost_to_go

template<FieldType T>

template<typename cost_t>

std::vector<std::vector<cost_t> > CECCO::Trellis< T >::ListViterbi_Workspace< cost_t >::cost_to_go

Minimum cost from each vertex (by layer and id) to any final-layer vertex.

Definition at line 336 of file graphs.hpp.

edge_costs

template<FieldType T>

template<typename cost_t>

std::vector<std::vector<cost_t> > CECCO::Trellis< T >::ListViterbi_Workspace< cost_t >::edge_costs

Edge cost for each segment and edge index.

Definition at line 334 of file graphs.hpp.

init

template<FieldType T>

template<typename cost_t>

cost_t CECCO::Trellis< T >::ListViterbi_Workspace< cost_t >::init

staticconstexpr

Initial value:

                         =
is_soft ? std::numeric_limits<cost_t>::infinity() : std::numeric_limits<cost_t>::max()

Cost of an unreachable vertex or an infeasible path.

Definition at line 303 of file graphs.hpp.

is_soft

template<FieldType T>

template<typename cost_t>

bool CECCO::Trellis< T >::ListViterbi_Workspace< cost_t >::is_soft = std::is_floating_point_v<cost_t>

staticconstexpr

True for floating-point soft metrics.

Definition at line 301 of file graphs.hpp.

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The documentation for this struct was generated from the following file:

• graphs.hpp