MATLAB simulation of OFDM techniques for VLC in indoor environments

MATLAB simulation of OFDM techniques for VLC in indoor environments

OFDM Stand for “Orthogonal Frequency Division Multiplexing”that is used by the VLC (VisibleLight Communication) system which decrease an impacts of the inter symbols with the interferences. During severalcases, a significant problem is the OFDM-based for VLC systems is thehigh PAPRS(peak to average power ratios)(Chen, 2017).Normally the VLC systems is consists of three parts , transmitter, receivers as well as channels as shown in below figure

VLC system Bock Diagram

 Requirements:

1)      A simulation code in Matlab is desired for the comparison of OFDM techniques for VLC in indoor environments.

OFDM systems used the Viterbi that is the channel decoder on the behalf of the VLC systems. The OFDM has the advantage over a conventional wireless for the communication systems due to the efficiency of the bandwidth. ODFM is used for the multicarrier of the transmit data for the high speed(Adiono & et.al, 2017). 

Now the MATALB simulation of the OFDM, covers the transmitter OFDM as well as OFDM of receiversthat is the basic chain coded in the MATALB.First of presents the OFDM transmitters.

Now the below MTALAB Code is the BER in OFDM systems that the modulation of the 16 QAM.

Results

OFDM in VLC Environmentof MATLAB simulations

Resultsof MATLAB simulation of OFDM techniques for VLC in indoor environments

 

2)      The techniques to be compared and analyzed are: DCO-OFDM, ACO-OFDM and ADO-OFDM.

The DC bias is added in the signal for the making it positivesin the DCO-OFDM. And in the DCO-OFDM the bias is added in the signals that make it positives. In the average optical power for a constellation like the 4QAM, 16-QAM, as well as 64-QAM the DCO-OFDM is the less efficient as compare to the ACO-OFDM. But in the largerconstellations the DCO-OFDM is more efficientbecause the DC bias is used in the DCO-OFDM(Dissanayake, 2013).

Through the clipping of the originalbipolar OFDM the transmitted signal is created it positives wherethe signal is zero as well as its transmittingthepositivesparts. The odd subcarriers that transmit the data in the ACO-OFDM.ACO-OFDM isutilized for the identification ofthesamples that is receivedthe signals whichis likely the addition ofNosie. During the diversityof the combining systems forthe ACO-OFDM is presented the nonlinearprocessing’sthat the signal received form the even sub-carriers. Now in this section the comparison of the ACO-OFDM, ADO-OFDM, as well as DCO-OFDM is explained. The odd Subcarrier is usedin the ADO-OFDM and in the ACO-OFDM, along with the even subcarriers is used in the DCO-OFDM.

The DCO-OFDM transmitter is shown in below figure;

DCO-OFDM systems

3)      A functional simulation code is needed, with comments on the lines of code.

First the OFDM simulation given the codingofthetransmitter as shown in below code

MATLB results

PAPR Graph of MATLAB simulation of OFDM techniques for VLC in indoor environment

Now this MATLB coding is about the PAPR in the OFDM of the VLC environments

Resultsof MATLAB simulation of OFDM techniques for VLC in indoor environments

 

4)      The result of the simulation will be the techniques compared in terms of BER and PAPR (graphs)

The above two graph of the BER graph in the OFDMsystem that shows the spaces of the Data pointsit means the lines have more spaces as compare to eth PAPR graph as shown in the above graph.