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DDC has a wide breadth of communications talent and experience. DDC tends to be on the high end in terms of complexity and algorithmic sophistication, and we ultimately culminate our experience in the most advanced applications and highest levels of integration, using SoC (System On a Chip) technologies. Our communications applications expertise loosely falls into 2 general categories, as outlined below. We use the most proven techniques in system design and verification, particularly by extensive modeling in Matlab, Simulink, or C, for algorithmic verification and experimentation, and also for test vector generation for verification of the hardware or software product. |
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| Military Communications and Signal Processing | |
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DDC has researched, architected, then developed,
implemented, and tested the actual hardware, for all communications /
signal processing elements in several different communication systems,
most notably an SOQPSK (i.e. shaped offset QPSK) telemetry system, and
a BPSK satellite receiver. They both were in the 1Mbps-20Mbps range.
The SOQPSK variant is QPSK at the core, but uses smooth phase transitions
(and not linear smooth, but in the shape of a raised cosine, spread over
multiple symbols). The advantage is very good spectral efficiency, with
virtually no impact on detection efficiency. This system is deployed
in a hostile environment, so extreme measures had to be employed to protect
from noise induced by vibrations, other nearby transmitters, etc. The
design approach used an under-deviated carrier rather than VCOs (this
was a VCO-less design, since VCOs are usually a significant source of
noise over all environmental conditions), and was fully modeled in Matlab
against a reference demodulator in Simulink, which measured various system
performance parameters (e.g. PSD, EVM, etc.). The BPSK satellite receiver
used carrier and subcarrier tracking (Costas loops), and was detecting
a signal buried in noise, with a very low data rate / sub-carrier ratio
(i.e. very complex).
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| Consumer / Industrial Communications and Signal processing |
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DDC has developed several ASICs, FPGAs, and SoCs
for consumer / industrial communications. A good example was a wireless
internet digital transceiver. which functions included a Coldfire processor
packet based interface, Reed Solomon/convolutional coding, OFDM modulator/demodulator,
timing acquisition, and filtering. The design was prototyped using an
FPGA prior to conversion to ASIC. DDC also has extensive experience in
cellular communications (particularly TDMA, GSM, and CDMA), and has performed
work for companies such as Motorola, PrairieComm, and Qualcomm.
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Communications Applications |
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| Communications Experience | |
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| DDC Communications Intellectual Property | |
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Communications/DSP Expertise 3820 Ventura Dr. Arlington Hts. IL 60004
Phone: 847-359-3828 Fax: 847-359-5418
© Copyright 2001-2007 Digital Design Corporation. All rights reserved.