free5GRAN::phy::transport_channel Namespace Reference

Functions
int	compute_N_polar_code (int E, int K, int nmax)
void	rate_recover (int *input_bits, int *output_bits, int i_bil, int E, int N, int K)
void	polar_decode (int *input_bits, int *output_bits, int N, int K, int nmax, int i_il, int n_pc, int n_wm_pc, int E)
void	crc_validate (int *input_bits, int *crc_polynom, int *remainder, int length_input, int length_crc)
void	compute_crc (int *input_bits, int *crc_polynom, int *remainder, int length_input, int length_crc)
void	compute_ldpc_base_graph (int A, float R, int &graph)
void	compute_transport_block_size (int n_re, float R, int mod_order, int num_layers, int nrb, int &tbs)
void	compute_Zc_dl_sch (int kb, float k_p, int &Zc, int &i_ls)
void	compute_code_block_segmentation_info_ldpc (int graph, int B, int &Zc, int &K, int &i_ls, int &L, int &C, int &N, int &K_p)
void	rate_recover_ldpc (int *input_bits, int N, int i_lbrm, int E, int id_rv, int mod_order, int C, int Zc, int graph, int K, int K_p, int *output_sequence)
void	rate_recover_ldpc (double *input_bits, int N, int i_lbrm, int E, int id_rv, int mod_order, int C, int Zc, int graph, int K, int K_p, double *output_sequence)
void	compute_circular_permutation_matrix (int size, int offset, int **matrix)
void	ldpc_decode_one_bit (vector< vector< int >> R, double *soft_bits, int i, double &new_bit)
void	compute_H_matrix_ldpc (int Zc, int graph, int i_ls, vector< vector< int >> &matrix, int &size_i, int &size_j)
void	ldpc_decode (double *input_bits, int N, int Zc, int graph, int K, int i_ls, int *output_sequence)
void	decode_bch (int *bch_bits, bool &crc_validated, int *mib_bits, int pci)
void	decode_dci (int *dci_bits, int E, int K, int *rnti, bool &validated, int *decoded_dci_bits)
vector< int >	decode_dl_sch (double *dl_sch_bits, int n_re, float R, int nrb, int E, bool &validated, free5GRAN::dci_1_0_si_rnti dci_1_0_si_rnti)

Function Documentation

compute_circular_permutation_matrix()

void free5GRAN::phy::transport_channel::compute_circular_permutation_matrix	(	int	size,
		int	offset,
		int **	matrix
	)

Compute offset times right shifted identity matrix of size n

Parameters

[in]	size	Identity matrix size
[in]	offset	Number of times to shift matrix
[out]	matrix	Output matrix

Definition at line 718 of file transport_channel.cpp.

compute_code_block_segmentation_info_ldpc()

void free5GRAN::phy::transport_channel::compute_code_block_segmentation_info_ldpc	(	int	graph,
		int	B,
		int &	Zc,
		int &	K,
		int &	i_ls,
		int &	L,
		int &	C,
		int &	N,
		int &	K_p
	)

Compute code block segmentation informations for LDPC

3GPP standard: TS 38.212 V15.2.0 Section 5.2.2

Parameters

[in]	graph	LDPC base graph
[in]	B	Code block segmentation input size (inlcuding CRC)
[out]	Zc	Returned LDPC lifting size
[out]	K	Code block segmentation output size
[out]	i_ls	Zc set index
[out]	L	Code block CRC length
[out]	C	Number of code blocks
[out]	N	LDPC output sequence
[out]	K_p	K' intermediate K value

Definition at line 545 of file transport_channel.cpp.

compute_crc()

void free5GRAN::phy::transport_channel::compute_crc	(	int *	input_bits,
		int *	crc_polynom,
		int *	remainder,
		int	length_input,
		int	length_crc
	)

CRC computation

Compute the CRC for a given input and polynom

Parameters

[in]	input_bits	Input bits sequence
[in]	crc_polynom	Polynom used for CRC computation
[out]	remainder	Output CRC
[in]	length_input	Input size
[in]	length_crc	Polynom size

Definition at line 392 of file transport_channel.cpp.

compute_H_matrix_ldpc()

void free5GRAN::phy::transport_channel::compute_H_matrix_ldpc	(	int	Zc,
		int	graph,
		int	i_ls,
		vector< vector< int >> &	matrix,
		int &	size_i,
		int &	size_j
	)

Compute Hbg matrix for LDPC

3GPP standard: TS 38.212 V15.2.0 Section 5.3.2

Parameters

[in]	Zc	LDPC lifting size
[in]	graph	LDPC base graph
[in]	i_ls	Zc set index
[out]	matrix	H matrix
[out]	size_i	H matrix number of rows
[out]	size_i	H matrix number of columns

Definition at line 786 of file transport_channel.cpp.

compute_ldpc_base_graph()

void free5GRAN::phy::transport_channel::compute_ldpc_base_graph	(	int	A,
		float	R,
		int &	graph
	)

Choose LDPC base graph

3GPP standard: TS 38.212 V15.2.0 Section 7.2.2

Parameters

[in]	A	Transport block size
[in]	R	Code rate
[out]	graph	Output graph

Definition at line 471 of file transport_channel.cpp.

compute_N_polar_code()

int free5GRAN::phy::transport_channel::compute_N_polar_code	(	int	E,
		int	K,
		int	nmax
	)

Compute polar coding out sequence size

3GPP standard: TS 38.212 V15.2.0 Section 5.3.1

Parameters

[in]	E	Rate matching output sequence length
[in]	K	Polar coding input sequence length (including CRC)
[in]	nmax	Maximum value of n

Returns

Polar coding out sequence size

Definition at line 41 of file transport_channel.cpp.

compute_transport_block_size()

void free5GRAN::phy::transport_channel::compute_transport_block_size	(	int	n_re,
		float	R,
		int	mod_order,
		int	num_layers,
		int	nrb,
		int &	tbs
	)

Transport block size computation

3GPP standard: TS 38.214 V15.2.0 Section 5.1.3.2

Partial implementation: n_info > 3824 not implemented

Parameters

[in]	n_re	Number of PDSCH RE per RB
[in]	R	Code rate
[in]	mod_order	Modulation order
[in]	num_layers	Number of transport layers
[in]	nrb	Number of RB in PDSCH allocation
[out]	tbs	Transport block size

Definition at line 488 of file transport_channel.cpp.

compute_Zc_dl_sch()

void free5GRAN::phy::transport_channel::compute_Zc_dl_sch	(	int	kb,
		float	k_p,
		int &	Zc,
		int &	i_ls
	)

Compute LDPC lifting size for DL-SCH encoding/decoding

3GPP standard: TS 38.212 V15.2.0 Section 5.2.2

Parameters

[in]	kb	Intermediate value for Zc computation
[in]	k_p	K' value
[out]	Zc	Returned value
[out]	i_ls	Zc set index

Definition at line 523 of file transport_channel.cpp.

crc_validate()

void free5GRAN::phy::transport_channel::crc_validate	(	int *	input_bits,
		int *	crc_polynom,
		int *	remainder,
		int	length_input,
		int	length_crc
	)

CRC validation

Computes the remainder of the division of the input sequence by the polynom. If the remainder is equal to 0, CRC is validated

Parameters

[in]	input_bits	Input bits sequence
[in]	crc_polynom	Polynom used for CRC computation
[out]	remainder	Output remainder of the division
[in]	length_input	Input size
[in]	length_crc	Polynom size

Definition at line 297 of file transport_channel.cpp.

decode_bch()

void free5GRAN::phy::transport_channel::decode_bch	(	int *	bch_bits,
		bool &	crc_validated,
		int *	mib_bits,
		int	pci
	)

Decode broadcast channel

3GPP standard: TS 38.212 V15.2.0 Section 7.1

Details:

• Rate recovering
• Polar decoding
• CRC validation
• Scrambling
• Payload de-interleaving

Parameters

[in]	bch_bits	Input bits sequence
[out]	crc_validated	Indicator for CRC validation
[out]	mib_bits	Output MIB bits
[in]	pci	Cell PCI

Definition at line 936 of file transport_channel.cpp.

decode_dci()

void free5GRAN::phy::transport_channel::decode_dci	(	int *	dci_bits,
		int	E,
		int	K,
		int *	rnti,
		bool &	validated,
		int *	decoded_dci_bits
	)

DCI decoding

3GPP standard: TS 38.212 V15.2.0 Section 7.3

Partial implementation: Only DCI Format 1_0 has been tested

Details:

• Rate recovering
• Polar decoding
• RNTI scrambling
• CRC validation

Parameters

[in]	dci_bits	Input bits sequence
[in]	E	PDCCH payload size
[in]	K	DCI payload size (including CRC)
[in]	rnti	RNTI for identifying DCI Format
[out]	validated	Indicator for CRC validation
[out]	decoded_dci_bits	Output bits sequence

Definition at line 1044 of file transport_channel.cpp.

decode_dl_sch()

vector< int > free5GRAN::phy::transport_channel::decode_dl_sch	(	double *	dl_sch_bits,
		int	n_re,
		float	R,
		int	nrb,
		int	E,
		bool &	validated,
		free5GRAN::dci_1_0_si_rnti	dci_1_0_si_rnti
	)

DL-SCH decoding

3GPP standard: TS 38.212 V15.2.0 Section 7.2

Partial implementation: Implemented for one code block (C=1)

Details:

• Rate recovering
• LDPC decoding
• CRC validation

Parameters

[in]	dl_sch_bits	Input soft bits sequence
[in]	n_re	Number of RE per PDSCH RB
[in]	R	Code Rate
[in]	nrb	Number of PDSCH allocated RB
[in]	E	PDSCH output sequence length
[out]	validated	CRC validation indicator
[in]	dci_1_0_si_rnti	Input DCI Format 1_0 object

Definition at line 1112 of file transport_channel.cpp.

ldpc_decode()

void free5GRAN::phy::transport_channel::ldpc_decode	(	double *	input_bits,
		int	N,
		int	Zc,
		int	graph,
		int	K,
		int	i_ls,
		int *	output_sequence
	)

Compute H matrix for LDPC using Belief propagation algorithm

3GPP standard: TS 38.212 V15.2.0 Section 5.3.2

Details:

• Compute H matrix
• Recover LDPC input bits from input sequence
• Compute columns and row bit relations
• Iterate 10 time:

1. Try to correct each input bit value
2. If H times corrected bits value equals 0, algorithm ends, otherwise it continues

Parameters

[in]	input_bits	Input soft bits sequence
[in]	N	LDPC input bit sequence length
[in]	Zc	LDPC lifting size
[in]	graph	LDPC base graph
[in]	K	Code block length
[in]	i_ls	Zc set index
[out]	output_sequence	Corrected output bits sequence

Definition at line 821 of file transport_channel.cpp.

ldpc_decode_one_bit()

void free5GRAN::phy::transport_channel::ldpc_decode_one_bit	(	vector< vector< int >>	R,
		double *	soft_bits,
		int	i,
		double &	new_bit
	)

LDPC correct one bit value (using belief propagation algorithm)

Parameters

[in]	R	Input set of rows connected to bit i
[in]	soft_bits	Input soft bits
[in]	i	Bit index
[out]	new_bit	New bit value

Definition at line 735 of file transport_channel.cpp.

polar_decode()

void free5GRAN::phy::transport_channel::polar_decode	(	int *	input_bits,
		int *	output_bits,
		int	N,
		int	K,
		int	nmax,
		int	i_il,
		int	n_pc,
		int	n_wm_pc,
		int	E
	)

Polar decoding

3GPP standard: TS 38.212 V15.2.0 Section 5.3.1

Partial implementation: Only n_wm_pc=0 is implemented

Details:

• Polar decoding using Gn inverse matrix
• Computing required sets
• Recover c'
• De-interleave c' to recover output

Parameters

[in]	input_bits	Input bits sequence
[out]	output_bits	Output bits sequence
[in]	N	Rate matching input sequence length
[in]	K	Polar coding input sequence length (including CRC)
[in]	nmax	Maximum value of n
[in]	i_il	Interleaving indicator (0: No interleaving, 1: Interleaving)
[in]	n_pc	Number of parity check bits
[in]	n_wm_pc	Number of other parity check bits

Definition at line 125 of file transport_channel.cpp.

rate_recover()

void free5GRAN::phy::transport_channel::rate_recover	(	int *	input_bits,
		int *	output_bits,
		int	i_bil,
		int	E,
		int	N,
		int	K
	)

Rate recovering for polar coding.

3GPP standard: TS 38.212 V15.2.0 Section 5.4.1

Partial implementation: Code block de-interleaving not implemented

Parameters

[in]	input_bits	Input bits sequence
[out]	output_bits	Output bits sequence
[in]	i_bil	Coded blocks interleaving indicator (0: No interleaving, 1: Interleaving)
[in]	E	Rate matching output sequence length
[in]	N	Rate matching input sequence length

Definition at line 74 of file transport_channel.cpp.

rate_recover_ldpc() [1/2]

void free5GRAN::phy::transport_channel::rate_recover_ldpc	(	int *	input_bits,
		int	N,
		int	i_lbrm,
		int	E,
		int	id_rv,
		int	mod_order,
		int	C,
		int	Zc,
		int	graph,
		int	K,
		int	K_p,
		int *	output_sequence
	)

Rate recovering for LDPC (hard bits)

3GPP standard: TS 38.212 V15.2.0 Section 5.4.2

Parameters

[in]	input_bits	DL-SCH input bits
[in]	N	Output sequence length
[in]	i_lbrm	Indicator for N_cb computation
[in]	E	DL-SCH input sequence length
[in]	id_rv	Redundancy version
[in]	mod_order	Modulation order
[in]	C	Number of code blocks
[in]	Zc	LDPC lifting size
[in]	graph	LDPC base graph
[in]	K	Code block length
[in]	K_p	K' code block intermediate length
[out]	output_sequence	Output bits

Definition at line 592 of file transport_channel.cpp.

rate_recover_ldpc() [2/2]

void free5GRAN::phy::transport_channel::rate_recover_ldpc	(	double *	input_bits,
		int	N,
		int	i_lbrm,
		int	E,
		int	id_rv,
		int	mod_order,
		int	C,
		int	Zc,
		int	graph,
		int	K,
		int	K_p,
		double *	output_sequence
	)

Rate recovering for LDPC (soft bits)

3GPP standard: TS 38.212 V15.2.0 Section 5.4.2

Parameters

[in]	input_bits	DL-SCH input soft bits
[in]	N	Output sequence length
[in]	i_lbrm	Indicator for N_cb computation
[in]	E	DL-SCH input sequence length
[in]	id_rv	Redundancy version
[in]	mod_order	Modulation order
[in]	C	Number of code blocks
[in]	Zc	LDPC lifting size
[in]	graph	LDPC base graph
[in]	K	Code block length
[in]	K_p	K' code block intermediate length
[out]	output_sequence	Output soft bits

Definition at line 653 of file transport_channel.cpp.