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Advanced satellite communication systemThe objective of this research program was to develop an innovative advanced satellite receiver/demodulator utilizing surface acoustic wave (SAW) chirp transform processor and coherent BPSK demodulation. The algorithm of this SAW chirp Fourier transformer is of the Convolve - Multiply - Convolve (CMC) type, utilizing off-the-shelf reflective array compressor (RAC) chirp filters. This satellite receiver, if fully developed, was intended to be used as an on-board multichannel communications repeater. The Advanced Communications Receiver consists of four units: (1) CMC processor, (2) single sideband modulator, (3) demodulator, and (4) chirp waveform generator and individual channel processors. The input signal is composed of multiple user transmission frequencies operating independently from remotely located ground terminals. This signal is Fourier transformed by the CMC Processor into a unique time slot for each user frequency. The CMC processor is driven by a waveform generator through a single sideband (SSB) modulator. The output of the coherent demodulator is composed of positive and negative pulses, which are the envelopes of the chirp transform processor output. These pulses correspond to the data symbols. Following the demodulator, a logic circuit reconstructs the pulses into data, which are subsequently differentially decoded to form the transmitted data. The coherent demodulation and detection of BPSK signals derived from a CMC chirp transform processor were experimentally demonstrated and bit error rate (BER) testing was performed. To assess the feasibility of such advanced receiver, the results were compared with the theoretical analysis and plotted for an average BER as a function of signal-to-noise ratio. Another goal of this SBIR program was the development of a commercial product. The commercial product developed was an arbitrary waveform generator. The successful sales have begun with the delivery of the first arbitrary waveform generator.
Document ID
19940027971
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Staples, Edward J.
(Amerasia Technology, Inc. Westlake Village, CA, United States)
Lie, Sen
(Amerasia Technology, Inc. Westlake Village, CA, United States)
Date Acquired
September 6, 2013
Publication Date
May 1, 1992
Subject Category
Communications And Radar
Report/Patent Number
NASA-CR-194211
NAS 1.26:194211
Accession Number
94N32477
Funding Number(s)
CONTRACT_GRANT: SBIR-14.05-9388
CONTRACT_GRANT: NAS3-25862
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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