Discrete Multitone Modulation Simulation

A script with a strip down version of a DMT Adsl system.

Description

The following is a simulation of the DMT system, similar to implementation as done in ADSL systems. The bandwidth has been divided into 32 sub-channels of equal width. Each sub-channel has been allocated bits in the range of 1-15 bits/symbol/Hz.

In a finite length DMT system, the effective length of the channel impulse response, ?V? will cause inter-block interference. To counter the effects of ISI, cyclic prefix is applied to the modulated block after a parallel to serial conversion. The length of cyclic prefix will be the same as ?V?. In this simulation a cyclic prefix of length 5 has been used.

The simulation is performed with three channel responses 1) an ideal channel 2) channel with effective length ?V+1? and 3) channel with effective length greater than ?V+1?. In all cases the channel is modeled as a low pass FIR filter with varying magnitude with frequency.

• MATLAB release: MATLAB 6.0 (R12)

[zoubiri abdelhak]

 

[muyangwe mudenda]

i want to learn more

[Alexandr Rybonka]

 

[durba ghosh]

good

[Vrao S]

Really Good

[Venkateswara rao]

 

[Vrao rao]

 

[wael sakr]

i am comonucation engineer in tishreen univircity

[Noah M]

 

[yawer shaikh]

ur function figure,freqz(h) at line 114 dosnt wrk it says it is an invalid funtion .... i found out dat freqz takes more arguments then u hav given to it ... i am at the moment wrkin on da sme project an havin a hell of a bad time doing it mate ....if u can plzz help

[Osmer Parabavire]

hola, aun no reviso el codigo, pero se ve bien.. Y ademas es un punto de partida muy bueno para investigaciones futuras. From Venezuela

[hemalatha mekala]

I had the problem in line 114.

[jing xin]

 

[Phaneendra Venkata]

i would like to know why you take the ifft for 2*N points. I think it should work even if you have N point IFFT.

[Phaneendra Venkata]

i take back my question...i did not notice you were adding complex conjugate part

[kadir]

Hi,
I have a project DMT which realizes at MATLAB Simulink.İs there anyone deal with that ??

Contact:[e-mail]

[kasun priya]

i am doing a DMT project.i am struc with demux.anyone know about that?????????