free5GRAN::phy::synchronization Namespace Reference

Functions
void	search_pss (int &n_id_2, int &synchronisation_index, float &peak_value, int cp_length, vector< complex< float >> &buff, int fft_size)
void	cross_correlation (vector< complex< float >> in1, vector< complex< float >> in2, complex< float > *out, int size1, int size2)
void	get_sss (int &n_id_1, float &peak_value, vector< complex< float >> &buff, int fft_size, int n_id_2)
complex< float >	correlate (vector< complex< float >> in1, int *in2, int size)

Function Documentation

correlate()

complex< float > free5GRAN::phy::synchronization::correlate	(	vector< complex< float >>	in1,
		int *	in2,
		int	size
	)

Simple correlation between two signals

Parameters

[in]	in1	Signal 1
[in]	in2	Signal 2
[in]	size	Signals size

Returns

Complex correlation value

Definition at line 306 of file synchronization.cpp.

cross_correlation()

void free5GRAN::phy::synchronization::cross_correlation	(	vector< complex< float >>	in1,
		vector< complex< float >>	in2,
		complex< float > *	out,
		int	size1,
		int	size2
	)

Perform cross correlation (i.e. moving window correlation) between signal 1 and signal 2

Parameters

[in]	in1	Signal 1
[in]	in2	Signal 2
[out]	out	Correlation result
[in]	size1	Signal 1 size
[in]	size2	Signal 2 size

Definition at line 196 of file synchronization.cpp.

get_sss()

void free5GRAN::phy::synchronization::get_sss	(	int &	n_id_1,
		float &	peak_value,
		vector< complex< float >> &	buff,
		int	fft_size,
		int	n_id_2
	)

Search for SSS sequence value.

Details:

• Retrieve frequency domain input signal
• Generate 336 possible freq domain SSS signals for N_ID_1 in [0,335]
• Correlate every signals to input freq domain signal
• Return N_ID_1 with highest correlation

Parameters

[out]	n_id_1	N_ID_1 with highest correlation peak
[out]	peak_value	Peak value
[in]	buff	Input IQ signal
[in]	fft_size	FFT size
[in]	n_id_2	N_ID_2 value computed by search_pss function

Definition at line 233 of file synchronization.cpp.

search_pss()

void free5GRAN::phy::synchronization::search_pss	(	int &	n_id_2,
		int &	synchronisation_index,
		float &	peak_value,
		int	cp_length,
		vector< complex< float >> &	buff,
		int	fft_size
	)

Search for PSS correlation peak inside a signal.

Details:

• Generating the three possible PSS sequences (for N_ID_2 in [0,1,2])
• Performing iFFT to retreive Time domain PSS sequence
• Cross-correlation between received signal and three time domain PSS signals
• Return PSS sequence with highest correlation peak.

Parameters

[out]	n_id_2	Returned N_ID_2
[out]	synchronisation_index	Synchronization index corresponding to correlation peak
[out]	peak_value	Peak height
[in]	cp_length	Cyclic prefix length
[in]	buff	Input IQ signal
[in]	fft_size	FFT size and symbol size

Definition at line 32 of file synchronization.cpp.