In Previous Post, we discussed How to calculate SNR for Indoor VLC Check Here

Now Using SNR we can calculate BER(Bit Error Rate )for Indoor VLC system. Normally BER rate would be 10-3 is Great in every communication system. Indoor VLC system gives BER in Range of 10-2 to 10-6. Indoor VLC is Give result variation at Angle of Tx (Transmitter) and Rx(Receiver), In another word we can be called it’s LOS(Line of Sight). Indoor VLC give accurate Result on -45 To 45 Angle. In that Range, We can get average 10-5 BER.

BER depends on the modulation scheme and SNR of the system. Where Q is a function that depends upon the modulation scheme which used.

BER = Q√SNR

We have implemented the VLC channel in MATLAB. Now irradiance angle and incidence angle depend on the receiver’s position in the room. At different incidence angles and irradiance angles, we have measure SNR and BER. It is measured for the transmitter and receiver are in-line, we get maximum SNR and low BER. Performance graphs of SNR and BER are shown in Fig, 1 and Fig, 2 respectively.

As discuss above FOV affect the performance of VLC system. For different transmitter’s FOV we can calculate SNR. Assume that the receiver is in the line of a transmitter. Transmitter’s FOV versus SNR graph is shown in Fig, 5As shown in the graph, to achieve high SNR, the transmitter’s FOV should be set above 50. One another important point is maximum SNR is achieved at FOV equal to 90.

For analyze VLC system performance, we assume some parameter for a room, LED, receiver and noise. That parameter listed in below Table, 1 [8] [2] [1].

VLC Ideal Parameter | ||

Type | Parameter | Value |

Transmitter | Number of Transmitters (LED) | 1 |

Power Radiated by LED | 1W | |

Angle of Irradiance | 70 | |

Field of View (FOV) | 70 | |

LED location in Room | [2,2,2] | |

Room & Other | Size of Room [W x L x H] | [4 x 4 x 2] m |

Noise Current | 0.562 Amp | |

Amplifier Bandwidth Factor | 50e6 | |

Ambient Light Power | 5e-12 Amp | |

Data Rate | 1e6 b/s | |

Distance Between Tx and Rx | 1m | |

Filter Coefficient | 1 | |

Electron Charge | 1.6e-19 | |

Receiver | Photodector Area | 1e-4 cm2 |

Angle of Irradiance | 70 | |

Field of View (FOV) | 90 | |

Responsivity | 1 A/W | |

Photodector Concentrator Refractive Index | 1.46 |

**CONCLUSION :**

In Single Input Single Output (SISO) VLC system we get High SNR and low BER for LOS transmitter and receiver’s positions. So, Irradiance angle and incidence angle must be less than 45 to achieve good signal. Now transmitter FOV should be always above 50 to get maximum SNR. Using MIMO RC technique increase SNR of the system. VLC system support up to 10 Gbps system.