PSS Search and Frequency Offset Correction
PSS search and frequency correction.
blockType: PSSSearchandFrequencyOffsetCorrection
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Path in the library: |
Description
The PSS Search and Frequency Correction unit receives a 5G baseband NR downlink signal at the input and performs a PSS search and a rough estimate of the frequency offset by performing the following steps:
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The frequency shift of the received signal to the intended frequency shift. The estimated shifts are located at a distance of half of the subcarrier frequency from each other.
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Comparing the frequency-shifted received signal with each of the three possible PSS sequences (NID2) and extracting the strongest correlation peak. The reference PSS sequences are frequency-centered. Therefore, the strongest correlation peak provides a measurement of the rough frequency offset relative to the center frequency of the carrier. The peak also indicates which of the three PSS sequences (NID2) was detected in the received signal and the time point of the best channel condition.
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Estimating the frequency offset below half of the subcarrier by comparing the cyclic prefix of each OFDM symbol in the SSB with the corresponding useful parts of the OFDM symbols. The phase of this correlation is proportional to the frequency shift in the signal.
Configuring the block includes setting the following parameters:
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Setting the frequency range Block Pattern: FR1:
Case A,Case B,Case C, FR2:Case D,Case E. -
Setting the number of transmitted information blocks Bitmap of SS blocks transmitted:
4,8,64. -
Setting the distance between subcarriers Subcarrier spacing (kHz):
15 kHzor30 kHzfor FR1,60 kHzor `120 kHz' for FR2. -
Setting the minimum channel bandwidth for the NR range Minimum channel bandwidth for the NRb (MHz) `5 MHz', `10 MHz', `40 MHz'.
Ports
Entrance
Wfm is a 5G-NR signal in the time domain in the form of a complex matrix
matrix
The 5G NR signal in the time domain, returned as a complex matrix. The number of columns of the matrix corresponds to the number of transmitting antennas.
Data type: ComplexF64
Output
Nid — detected PSS sequence (NID2) in the received pass signal:q[<br>] scalar
The detected PSS sequence (NID2) in the received signal.
Data type: Float64
SSBoff — the value of the frequency shift
scalar
The value of the frequency shift.
Data type: Float64
CorWfm is a frequency—shifted signal in the form of a complex matrix
matrix
The frequency offset of the signal returned as a complex matrix.
Data type: ComplexF64
Parameters
Main
Block Pattern — ID of the pass frequency range:q[<br>] Case A | Case B (default) | Case C | Case D | Case E
For the 5G standard, the frequency range used is specified in the documentation.
| Frequency range designation | Frequency range |
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FR1: |
410 MHz – 7125 MHz |
FR2: |
24250 MHz – 52600 MHz |
Block parameter |
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Values |
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By default |
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Bitmap of SS blocks transmitted — number of transmitted blocks of pass information:q[<br>] 4 | 8 (default) | 64
The number of transmitted information blocks.
Block parameter |
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Values |
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By default |
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Subcarrier spacing (kHz) — distance between subcarriers in kHz
15(default) | 30 | 60 | 120
The distance between subcarriers in kHz for all channels and carrier reference signals.
The values to select are 15 or 30 for FR1, 60 or 120 for FR2.
Block parameter |
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Values |
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By default |
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Minimum channel bandwidth for the NRb (MHz) — setting the minimum channel bandwidth for the NR pass range:q[<br>] 5 MHz (default) | 10 MHz | 40 MHz
Setting the minimum channel bandwidth for the NR band.
Block parameter |
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Values |
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By default |
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