---
name: "rte_bbdev_op_fft"
section: "3"
platform: "linux"
package: "dpdk-doc"
version: "24.11.4-0+deb13u1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/rte_bbdev_op_fft"
---

# rte\_bbdev\_op\_fft(3)

## NAME

rte\_bbdev\_op\_fft

## SYNOPSIS

`#include <rte_bbdev_op.h>`

### Data Fields

struct **rte\_bbdev\_op\_data** **base\_input**\
 struct **rte\_bbdev\_op\_data** **base\_output**\
 struct **rte\_bbdev\_op\_data** **dewindowing\_input**\
 struct **rte\_bbdev\_op\_data** **power\_meas\_output**\
 uint32\_t **op\_flags**\
 uint16\_t **input\_sequence\_size**\
 uint16\_t **input\_leading\_padding**\
 uint16\_t **output\_sequence\_size**\
 uint16\_t **output\_leading\_depadding**\
 uint8\_t **window\_index** \[RTE\_BBDEV\_MAX\_CS\_2\]\
 uint16\_t **cs\_bitmap**\
 uint8\_t **num\_antennas\_log2**\
 uint8\_t **idft\_log2**\
 uint8\_t **dft\_log2**\
 int8\_t **cs\_time\_adjustment**\
 int8\_t **idft\_shift**\
 int8\_t **dft\_shift**\
 uint16\_t **ncs\_reciprocal**\
 uint16\_t **power\_shift**\
 uint16\_t **fp16\_exp\_adjust**\
 int8\_t **freq\_resample\_mode**\
 uint16\_t **output\_depadded\_size**\
 uint16\_t **cs\_theta\_0** \[RTE\_BBDEV\_MAX\_CS\]\
 uint32\_t **cs\_theta\_d** \[RTE\_BBDEV\_MAX\_CS\]\

## Detailed Description

Operation structure for FFT processing.

The operation processes the data for multiple antennas in a single call (i.e. for all the REs belonging to a given SRS sequence for instance).

The output mbuf data structure is expected to be allocated by the application with enough room for the output data.

Definition at line **769** of file **rte\_bbdev\_op.h**.

## Field Documentation

### struct rte\_bbdev\_op\_data base\_input

Input data starting from first antenna.

Definition at line **771** of file **rte\_bbdev\_op.h**.

### struct rte\_bbdev\_op\_data base\_output

Output data starting from first antenna and first cyclic shift.

Definition at line **773** of file **rte\_bbdev\_op.h**.

### struct rte\_bbdev\_op\_data dewindowing\_input

Optional frequency window input data.

Definition at line **775** of file **rte\_bbdev\_op.h**.

### struct rte\_bbdev\_op\_data power\_meas\_output

Optional power measurement output data.

Definition at line **777** of file **rte\_bbdev\_op.h**.

### uint32\_t op\_flags

Flags from rte\_bbdev\_op\_fft\_flag\_bitmasks.

Definition at line **779** of file **rte\_bbdev\_op.h**.

### uint16\_t input\_sequence\_size

Input sequence size in 32-bits points.

Definition at line **781** of file **rte\_bbdev\_op.h**.

### uint16\_t input\_leading\_padding

Padding at the start of the sequence.

Definition at line **783** of file **rte\_bbdev\_op.h**.

### uint16\_t output\_sequence\_size

Output sequence size in 32-bits points.

Definition at line **785** of file **rte\_bbdev\_op.h**.

### uint16\_t output\_leading\_depadding

Depadding at the start of the DFT output.

Definition at line **787** of file **rte\_bbdev\_op.h**.

### uint8\_t window\_index\[RTE\_BBDEV\_MAX\_CS\_2\]

Window index being used for each cyclic shift output.

Definition at line **789** of file **rte\_bbdev\_op.h**.

### uint16\_t cs\_bitmap

Bitmap of the cyclic shift output requested.

Definition at line **791** of file **rte\_bbdev\_op.h**.

### uint8\_t num\_antennas\_log2

Number of antennas as a log2 – 8 to 128.

Definition at line **793** of file **rte\_bbdev\_op.h**.

### uint8\_t idft\_log2

iDFT size as a log2 - 32 to 2048.

Definition at line **795** of file **rte\_bbdev\_op.h**.

### uint8\_t dft\_log2

DFT size as a log2 - 8 to 2048.

Definition at line **797** of file **rte\_bbdev\_op.h**.

### int8\_t cs\_time\_adjustment

Adjustment of position of the cyclic shifts - -31 to 31.

Definition at line **799** of file **rte\_bbdev\_op.h**.

### int8\_t idft\_shift

iDFT shift down.

Definition at line **801** of file **rte\_bbdev\_op.h**.

### int8\_t dft\_shift

DFT shift down.

Definition at line **803** of file **rte\_bbdev\_op.h**.

### uint16\_t ncs\_reciprocal

NCS reciprocal factor.

Definition at line **805** of file **rte\_bbdev\_op.h**.

### uint16\_t power\_shift

Power measurement out shift down.

Definition at line **807** of file **rte\_bbdev\_op.h**.

### uint16\_t fp16\_exp\_adjust

Adjust the FP6 exponent for INT\<-\>FP16 conversion.

Definition at line **809** of file **rte\_bbdev\_op.h**.

### int8\_t freq\_resample\_mode

Frequency resampling : 0: Transparent Mode1: 4/3 Resample2: 2/3 Resample.

Definition at line **811** of file **rte\_bbdev\_op.h**.

### uint16\_t output\_depadded\_size

Output depadded size prior to frequency resampling.

Definition at line **813** of file **rte\_bbdev\_op.h**.

### uint16\_t cs\_theta\_0\[RTE\_BBDEV\_MAX\_CS\]

Time error correction initial phase.

Definition at line **815** of file **rte\_bbdev\_op.h**.

### uint32\_t cs\_theta\_d\[RTE\_BBDEV\_MAX\_CS\]

Time error correction phase increment.

Definition at line **817** of file **rte\_bbdev\_op.h**.

## Author

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