SECURE DATA TRANSMISSION USING BARCODE MODULATION METHOD FOR MOBILE DEVICES

In this study, a new approach for data modulation in 2-D barcodes is introduced, and its performance is evaluated in comparison to other standard methods of barcode modulation. In this new approach, orthogonal frequency-division multiplexing (OFDM) modulation is used together with differential phase shift keying (DPSK) over adjacent frequency domain elements. A barcode can be transferred from one mobile to another by capturing images. But the relative movements during capture can induce motion-blur distortions in the captured image. This problem can be solved by using orthogonal frequency division multiplexing (OFDM) modulation along with differential phase shift keying (DPSK). In this technique, a large number of closely spaced orthogonal sub-carriers carry the data on several parallel data streams or channels. The sub-carriers are modulated with any of the conventional modulation technique. Here DPSK modulation is used to modulate the sub-carriers. The modulation is performed in the message which is encoded as the barcode. The barcode is captured and then fast Fourier transform (FFT) is applied onto the decoded message. Then, original message is retrieved by performing demodulation. Since data is stored in phase difference, adjacent elements are less affected by the motion blur distortions