E in the LMS algorithm, the algorithm of error is the difference between desired signal and the received signal receiver, but in a communication system, we do not know what is the desired signal, so the significance of LMS??

CodePudding user response:

There was a pilot symbols to train equalizer makes it achieve convergence condition;
After the pilot, is the first symbol of the unknown, with the equalizer coefficients obtained from the training to deal with the data, get the equilibrium output, and then determine which it belongs to the constellation points;
The constellation points with the equilibrium output is presupposed, and get the error data, and then adjust the equalizer coefficients; This loop,

CodePudding user response:

Thank you for your reply but do you have any LMS algorithm matlab code

CodePudding user response:

Matlab, C code, but not in the computer,
LMS algorithm itself is very simple, only three lines of code, the focus of the equalizer is not here, also applied to solve several problems: feedforward, feedback filter sequence; Rapid convergence of the filter, LMS is very slow, wait for good convergence to hundreds of symbols, so try to limit the convergence within YiErShiGe symbols; Or to switch to other algorithms, such as the square root kalman, QRD - RLS;