# MATLAB Code for OFDM System

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1. Apr 27, 2014

### EngWiPy

Hello all,

Does it occur that anyone here working on OFDM communication systems? I need a MATLAB implementation of such systems in the continuous time. I will provide the math derivations if requested.

Thanks

2. May 4, 2014

### Greg Bernhardt

I'm sorry you are not finding help at the moment. Is there any additional information you can share with us?

3. May 5, 2014

### EngWiPy

Thanks for bringing up this thread.

Usually, for communication systems, simulations are done in discrete-time. It is easier to understand, and easier to simulate. However, in my case in particular, this discrete-time equivalence doesn't work perfectly, and hence I need to do the simulations in the continuous-time, as it is transmitted in practice.

In particular, I want to generate this received signal in MATLAB:

$$v(t)=\sum_{k=0}^{K-1}d_ke^{j2 \pi \frac{k}{T}t}\sum_{p=1}^{N_p}h_pe^{-j2 \pi f_k\tau_p}g(t-\tau_p)$$

where fk=f0+(k/T) is the kth subcarrier, T is the OFDM symbol duration, dk are the transmitted symbols, K is the number of subcarriers, hp are the path gains, taup are the paths delays, Np is the number of paths, and g(t) is a rectangular pulse of duration T+Tg and magnitude unity, where Tg is a guard interval.

This equation is obtain by transmitting the signal:

$$s(t)=\Re\{\sum_{k=0}^{K-1}d_ke^{j2 \pi f_k t}g(t)\}$$

over the channel:

$$h(\tau)=\sum_{p=1}^{N_p}h_p\delta(\tau-\tau_p)$$

where delta is the dirac delta function.

Any help is much appreciated.

Thanks