38 init_ tdlms

Purpose

Creates and initializes the variables required for the Transform Domain Least Mean Squares (TDLMS) Adaptive algorithm

Syntax

[W,w,x,d,y,e,p]=init_tdlms(L)
[W,w,x,d,y,e,p]=init_tdlms(L,W0,x0,d0)

Description

The variables of the TDLMS are summarized below (see Fig. 2.6 and Fig. 4.20).

Input Parameters [Size]:: 
   L   : number of filter coefficients
   W0  : initial T-domain coef. vector [L x 1] 
   x0  : initial input samples vector [L x 1] 
   d0  : initial desired sample [L x 1] 

Output parameters [default]::
   W   : initialized T-domain coef. vector [zeros]
   w   : initialized time-domain coef. vector [zeros]
   x   : initialized input vector [white noise]
   d   : initialized desired sample [white noise]
   y   : Initialized filter output
   e   : initialized error sample [e = d - y]
   p   : initialized power estimate

Example

L  = 5;           % Number of coefficients 
W0 = [1;0;0;0;0]; % initial filter coefficients 
x0 = rand(5,1);   % initial delay line
d0 = 0;           % desired sample

% Create and initialize a TDLMS FIR filter
[W,w,x,d,y,e,p]=init_tdlms(L,W0,x0,d0);

Remarks

• Supports both real and complex signals and filters.
• Use input parameters 2 through 4 to initialize the algorithm storage. This is helpful when the adaptation process is required to start from a known operation point calculated off-line or from previous simulations.

See Also

ASPTTDLMS, MODEL_ TDLMS.