Generating and Demodulating M-ary FSK-PSK Using the FFT.
Research rept. 1 Oct 96-1 Jan 97,
NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF ELECTRICAL AND COMPUTER ENGINEE RING
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This paper discusses a technique for modulating and demodulating M-ary FSK using an FFT based modem typical of Coded Orthogonal Frequency Division Modulation COFDM systems. COFDM is one of the more promising spectrally efficient, high data rate modulation techniques for line-of-sight communications between mobile platforms. This paper will show that legacy FSK radios like the ANMRC-142 binary FSK modulation at 144, 288, 576 kbps used by the U.S. Marine Corps could be easily implemented in a COFDM modem originally designed for higher data rates and better spectral efficiency than the legacy radio. In addition, the performance of such an implementation is analyzed in detail and shown to result in negligible performance degradation 0.05 dB or less. Digital processing speed requirements are analyzed and shown to be similar to digital implementation of conventional FSK receivers. MATLAB code is included that simulates the modem.
- Radiofrequency Wave Propagation
- Radio Communications