Sidelink Primary Synchronization Signal

The sidelink primary synchronization signal (S-PSS) is a m-sequence of length 127 generated using \(N_{ID,2}^{SL}\). It is used for time synchronization which aims to find the slot boundary by the user equipment (UE). The \(N_{ID,2}^{SL}\) provides a cyclic shift to a base sequence as defined in [3GPPTS38211_S_PSS].

Important

• S-PSS is an constituent of sidelink synchronization signal block (S-SSB). It is loaded in the middle 127 subcarrier (across frequency) of \(2^\text{th}\) and \(3^\text{th}\) symbol of the S-SSB.

The sidelink primary synchronization signal is generated as follows:

If \(N_{ID,2}^{SL}\) is scalar:

nID2         = 1           # Cell ID-2 for PSS generation
spss         = S_PSS(nID2) # Generate PSS object using this cell ID-2.
spssSequence = spss()      # Generate [1x127] pss sequence using 'pss' object

If \(N_{ID,2}^{SL}\) is NumPy array:

nID2         = np.array([1,0,1,1]) # Cell ID-2 for PSS generation
spss         = S_PSS(nID2)         # Generate PSS object using this cell ID-2.
spssSequence = spss()              # Generate [4x127] pss sequence using 'pss' object for each cell-ID2

The details about the input-output interface of the S-PSS implementation is provided below.

class toolkit5G.SequenceGeneration.S_PSS(nID2)

Generates the sidelink primary synchronization signal (S-PSS) for 5G system. The constructor expects one parameter as an input \(N_{ID}^2\) which can be a scaler and/or array. The call method returns 1 or multiple sidelink PS sequences of length 127 based on the number of \(N_{ID}^2\) passed as input. The details about the implementation of the sequence are provided in the document “Physical channels and modulation (Release 17)” TS 38.211 Section 8.4.2.2 version V17.1.0 (2022-03).

Note

As per 3GPP specifications, cell ID-1 \(N_{ID,2}^{SL} \in \{0, 1\}\).

Parameters:

nID2 (int or NumPy integer array) – \(N_{ID,2}^{SL}\): All the values should be the interval {0, 1}.

Input:

None – No inputs Required.

Output:

(…, 127), np.int8 – Sidelink Primary synchronization sequence of shape :math:` ext{N} imes 127` where N is the number of S-PSS sequences.

Raises:

• ValueError – [Error S_PSS]: ‘nID2’ must be an integer or integer numpy array!

• Warning – [Warning S_PSS]: ‘nID2’ should belong to interval {0, 1}!

• ValueError – [Error S-PSS]: ‘nID2’ must be an integer or integer numpy array!

References:

[3GPPTS38211_S_PSS]

3GPP TS 38.211 “Physical channels and modulation (Release 17)”, V17.1.0 (2022-03).