| Presentation | 2004/9/9 Spectral Analysis of Load Switching Signal from Contactless IC Card Sadahiko NAKANO, Yoshimitsu OHTANI, |
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| PDF Download Page | PDF download Page Link |
| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | This paper analyses the spectrum of the load switching signal from a contactless IC card. First, we expand the ideal load-switching signal to a Fourier series. Then we examine the signal's spectra by using the Discrete Fourier Transform (DFT), which imposes the condition that the window contain an integer quantity of cycles of the sub-carrier. We show that the amplitude of the sub-carrier spectra which appear as upper and lower sidebands of the carrier frequency, varies sinusoidally with the phase difference between the carrier and sub-carrier. Under the general condition where the DFT window does not contain an integer quantity of sub-carrier cycles, we show that the sub-carrier spectra vary sinusoidally with the number of sampling points. We can then get true values of the sub-carrier spectra by using scale-factors that reflect the difference between the average of fluctuating sub-carrier spectra and the actual amplitude. We call this process "the averaging method of DFT." We verify the above approach by using similar actual load-switching signals generated by signal generators. We found that finite bandwidth affects the transition when the sub-carrier's state is inverted such that the fluctuation of the sub-carrier spectra with carrier-phase difference is reduced. Taking this effect into account, we estimated the error of the averaging method of DFT. Measured values for the generated load-switching signals agree with the theoretically calculated values. Finally, we confirm the utility of the averaging method of DFT by applying it to real load-switching signals from contactless IC card. |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | contactless IC card / load-switching signal / Discrete Fourier Transform / spectral analysis |
| Paper # | EA2004-56,SIP2004-60,SIS2004-27 |
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| Conference Information | |
| Committee | SIP |
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| Conference Date | 2004/9/9(1days) |
| Place (in Japanese) | (See Japanese page) |
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| Topics (in Japanese) | (See Japanese page) |
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| Paper Information | |
| Registration To | Signal Processing (SIP) |
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| Language | JPN |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | Spectral Analysis of Load Switching Signal from Contactless IC Card |
| Sub Title (in English) | |
| Keyword(1) | contactless IC card |
| Keyword(2) | load-switching signal |
| Keyword(3) | Discrete Fourier Transform |
| Keyword(4) | spectral analysis |
| 1st Author's Name | Sadahiko NAKANO |
| 1st Author's Affiliation | Visual Media Communications Project, NTT Cyber Space Laboratories() |
| 2nd Author's Name | Yoshimitsu OHTANI |
| 2nd Author's Affiliation | Visual Media Communications Project, NTT Cyber Space Laboratories |
| Date | 2004/9/9 |
| Paper # | EA2004-56,SIP2004-60,SIS2004-27 |
| Volume (vol) | vol.104 |
| Number (no) | 305 |
| Page | pp.pp.- |
| #Pages | 6 |
| Date of Issue | |