Accession Number : ADA320248

Title :   Multichannel M-Ary Frequency-Shift-Keying Block Demodulator Implementation,

Corporate Author : DEFENCE RESEARCH ESTABLISHMENT OTTAWA (ONTARIO)

Personal Author(s) : Tom, Caroline ; Meng, Zaiqing

PDF Url : ADA320248

Report Date : DEC 1996

Pagination or Media Count : 68

Abstract : The Military Satellite Communications (MILSATCOM) group at Defence Research Establishment Ottawa (DREO) is performing in-house satellite communications uplink synchronization experiments. A critical part of the experiment is the block demodulation of the multi-channel frequency-hopped waveform. This report analyses the Fast Fourier transform (FFT)-based demodulator implemented by Royal Military College (RMC) Kingston. This system is capable of demodulating a 32 channel, 8-ary frequency-shift-keying (FSK) waveform. The implementation consists of analog-to-digital (A/D) conversion, FFT computation, and high speed input/output (I/O) interface processes using commercial off-the-shelf boards. A description of each of the boards is presented. The operational data flow of the system is examined. For the software implementation, a decimation-in-time approach is used in the digital signal processing (DSP) board to compute the discrete Fourier transform (DFT). A brief description of decimation-in-time algorithms is included. Key components of the assembly language program are outlined. A user's guide detailing the setup requirements for proper operation of the system is included with those required for the DREO application. Steps required for modification to the software are briefly discussed.

Descriptors :   *DEMODULATORS, *FREQUENCY SHIFT KEYERS, SIGNAL PROCESSING, USER MANUALS, WAVEFORMS, CANADA, INPUT OUTPUT PROCESSING, SATELLITE COMMUNICATIONS, FAST FOURIER TRANSFORMS, INPUT OUTPUT DEVICES, ANALOG TO DIGITAL CONVERTERS, DISCRETE FOURIER TRANSFORMS, FREQUENCY AGILITY, MULTICHANNEL, ASSEMBLY LANGUAGES.

Subject Categories : Radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE