Embedded Target for Texas Instruments C6000 DSPs

Complex FIR

Filter a complex input signal using a complex FIR filter

Library

C62x DSP Library--Filtering

Description

The Complex FIR block filters a complex input signal X using a complex FIR filter. This filter is implemented using a direct form structure.

The number of FIR filter coefficients, which are given as elements of the input vector H, must be even. The product of the number of elements of X and the number of elements of H must be at least four. Inputs, coefficients, and outputs are all Q.15 data types.

The Complex FIR block supports discrete sample times and little-endian code generation only.

Dialog Box

Coefficient source

Specify the source of the filter coefficients:

• Specify via dialog--Enter the coefficients in the Coefficients (H) parameter in the dialog
• Input port--Accept the coefficients from port H. This port must have the same rate as the input data port X.

Coefficients (H)

Designate the filter coefficients in vector format. There must be an even number of coefficients. This parameter is only visible when Specify via dialog is selected for the Coefficient source parameter. This parameter is tunable in simulation.

Initial conditions

If the initial conditions are

• All the same, you need only enter a scalar.
• Different within channels but the same across channels, enter a vector containing the initial conditions for one channel. The length of this vector must be one less than the number of coefficients.
• Different across channels, enter a matrix containing all initial conditions. The number of rows of this matrix must be one less than the number of coefficients, and the number of columns of this matrix must be equal to the number of channels.
  You may enter real-valued initial conditions. Zero-valued imaginary parts will be assumed.

Algorithm

In simulation, the Complex FIR block is equivalent to the TMS320C62x DSP Library assembly code function DSP_fir_cplx. During code generation, this block calls the DSP_fir_cplx routine to produce optimized code.

See Also

General Real FIR, Radix-4 Real FIR, Radix-8 Real FIR, Symmetric Real FIR

C6711 DSK RESET

Convert Floating-Point to Q.15