Wireless Channel Modelling

[er.rakeshjain]

wireless channel modelling

Dear all,
I have simulated WiMAX Transmitter and receiver in Matlab. Now I want to introduce channel effect between tx and Rx. Pls guide me to model the channel in MATLAB.
How can I add Fading effect and Delay Spread in Channel using Matlab.
How will I estimate channel at the receiver using pilots. I used pilots in my transmitted signal but at the receiver side simply extracting them. How pilots will be used to estimate channel and apply correction to the signal.

 

[HanyKM]

wireless channel

you can simply add flat Gaussian noise: randn command.

For the delay, you need to add different paths for the signal. each path had a certain delay amount (zeros at the beginning of the signal)
You then add all the paths together at the RX side.

Usually pilots are used to track the channel changes.
I believe the first estimation of the channel is to be done using a preamble.

Hope this helps !

Added after 2 minutes:

Sorry I mean Gaussian noise

remove the word "flat"

 

[er.rakeshjain]

channel modelling

How can I model multipaths and adding delay.

 

[HanyKM]

how to remove noise of wireless channel matlab

As I've just said, create many copies of the signal, each path is delayed by a certain delay amount modeled in ur code by adding zeros at the beginning of the signal.

---s i g n a l---
0 0 0 0 ---s i g n a l---
0 0 ---s i g n a l---
0 0 0 0 0 0 ---s i g n a l---

Then add all the paths at the RX side

Added after 4 minutes:

Don't forget to add the Amplitude level of each path too

 

[er.rakeshjain]

Dear,
I used rayligh fading to generate channel. Now I have faded subcarriers on the receiver side.How can I use extracted pilot carriers for channel estimation and then how to interpolate then.

 

[itrakib2005]

I need all the code. Could u please the give me the codes.