OFDM Demodulation

OFDM demodulation.

blockType: OFDMDemodulation

Path in the library:

/5G/OFDM Demodulation

Description

Block OFDM Demodulation estimates the synchronization offset to the strongest SS block using the PSS reference sequence (NID2). After correcting the frequency offset, it is considered that the central frequencies of the reference PSS and the received signal have aligned, after which the block OFDM Demodulation demodulates the synchronized signal and extracts the SS block.

The block performs the following actions:

Creates a reference grid for estimating time using the detected PSS usage. The PSS is placed in the second symbol OFDM of the reference grid, since the first symbol OFDM contains a special length of the cyclic prefix.
Estimates the synchronization offset relative to the OFDM symbol to the detected SSB based on the contents of the reference grid.
Performs synchronization, OFDM demodulation and extraction of the strongest SS block.

Configuring the block includes setting the following parameters:

Setting the frequency range Block Pattern: FR1: Case A, Case B, Case C, FR2: Case D, Case E.
Setting the number of transmitted blocks of information Bitmap of SS blocks transmitted: 4, 8, 64.
Setting the distance between subcarriers Subcarrier spacing (kHz): 15 kHz or 30 kHz for FR1, 60 kHz or 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

Input

# Nid — detected PSS sequence (NID2) in the received signal
scalar

Details

The detected PSS sequence (NID2) in the received signal.

Data types	`Float64`
Complex numbers support	No

# CorWfm — a frequency-shifted signal in the form of a complex matrix
the matrix

Details

A frequency-shifted signal returned as a complex matrix.

Data types	`ComplexF64`
Complex numbers support	No

Output

# ResGrid — demodulated output signal in the form of a complex matrix
the matrix

Details

The demodulated output signal returned as a complex matrix.

Data types	`ComplexF64`
Complex numbers support	No

Parameters

Main

# Block Pattern — id of the frequency range
Case A | Case B | Case C | Case D | Case E

Details

For the 5G standard, the frequency range used is specified in the documentation.

Frequency range designation Frequency range

Frequency range designation	Frequency range
FR1: `Case A`, `Case B`, `Case C`	`410` MHz – `7125` MHz
FR2: `Case D`, `Case E`	`24250` MHz – `52600` MHz

FR1: Case A, Case B, Case C

410 MHz – 7125 MHz

FR2: Case D, Case E

24250 MHz – 52600 MHz

Values	`Case A` \| `Case B` \| `Case C` \| `Case D` \| `Case E`
Default value	`Case B`
Program usage name	`BlockPattern`
Tunable	No
Evaluatable	No

# Bitmap of SS blocks transmitted — number of transmitted information blocks
4 | 8 | 64

Details

The number of transmitted information blocks.

Values	`4` \| `8` \| `64`
Default value	`8`
Program usage name	`TransmittedBlocks`
Tunable	No
Evaluatable	No

# Subcarrier spacing (kHz) — the distance between subcarriers in kHz
15 | 30 | 60 | 120

Details

The distance between subcarriers in kHz for all channels and carrier reference signals.

Values to choose from: 15 or 30 for FR1, 60 or 120 for FR2.

Values	`15` \| `30` \| `60` \| `120`
Default value	`15`
Program usage name	`SubcarrierSpacingCommon`
Tunable	No
Evaluatable	No

# Minimum channel bandwidth for the NRb (MHz) — setting the minimum channel bandwidth for the NR band in MHz
5 | 10 | 40

Details

Setting the minimum channel bandwidth for the NR band in MHz.

Values	`5` \| `10` \| `40`
Default value	`5`
Program usage name	`MinChannelBW`
Tunable	No
Evaluatable	No

References

Glossary: Standard 5G

Examples

Restoration of the main 5G information block