#Difference between ask psk fsk driver#

The parameters used in the simulation are shown in Table 1. And the bandwidths of these modulations are calculated according to the feature of the modulation. Now the performance of ASK, FSK and DPSK is given out according to data rate, transmission distance and incident angle respectively, whose model is the LOS model I mention above. In order to decrease the system complexity, we choose to use noncoherent demodulation, the bit error rate (BER) of ASK, FSK and DPSK is given by : And a PD can’t receive any signal if φ is larger than the field of view (FOV) of PD marked as Ψ. In this formula, A is the receiving area of PD, R is the PD sensitivity. Where is the perpendicular incidence intensity of the LED, m is the order of Lambertian radiation and the relationship between m and is given by Īnd then we can calculate the received power. The radiation pattern of LED is generally regarded as Lambertian pattern, therefore, the optical intensity atĪngle ϕ is. Finally, the distance between the LED and the PD is d. The angle of the LED’s half illuminance is, and the irradiance angle is, The photodiode’s (PD) light incident angle is, and the field of view of PD is. In a general LOS VLC system as shown in Figure 2, we define the parameters as follows. And then it is amplified and converted to voltage signal. The PD converts the signal from optical power to electrical current. The modulator refers to ASK, FSK and DPSK modulator in this paper, and the demodulator is the corres.

#Difference between ask psk fsk driver#

The transmitter consists of modulator, LED driver and LED, and the receiver is composed of photo detector (PD), amplifier, demodulator and decision device. Finally, the performance of OOK, FSK and DPSK is summed up.Īs shown in Figure 1, a general VLC system includes a transmitter and a receiver. Secondly, we do some simulation to show the BER influenced by data rate, transmission distance and incident angle respectively. In this paper, we look into the VLC system and figure out what influences the signal noise ratio (SNR) and bit rate error (BER) in the first section.

As it is almost as simple as ASK, we have done some analyses to FSK and DPSK, as well as compare them to ASK in a line-of-sight (LOS) VLC system, to see whether the performance can be improved when FSK or DPSK is introduced. But FSK, DPSK is seldom used in VLC system. VLC normally uses the ASK modulation technique, which is simple and widely used.

Visible Light Communication (VLC) can do better than radio wireless communication in confidentiality and it has no electromagnetic radiation so that it can be used in some special situation. In addition to lighting, LED can also be used for communication. Nowadays, Light-Emitting-Diodes (LEDs) are widely used and they have a lot of advantages, such as high energy and high brightness.