Broadband interference excision for software-radio spread-spectrum communications using time-frequency distribution synthesis.
A new method is introduced for interference excision in spread-spectrum communications that is conducive to software-radio applications. Spare processing capacity in the receiver permits the use of time–frequency techniques to synthesize a nonstationary interference from the time–frequency domain us...
| Main Authors: | , , |
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| Format: | |
| Language: | English |
| Published: |
1999
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| Online Access: | http://ezproxy.villanova.edu/login?url=https://digital.library.villanova.edu/Item/vudl:173198 |
| Summary: | A new method is introduced for interference excision
in spread-spectrum communications that is conducive to
software-radio applications. Spare processing capacity in the
receiver permits the use of time–frequency techniques to synthesize
a nonstationary interference from the time–frequency
domain using least squares methods. The synthesized signal is
then subtracted from the incoming data in the time domain,
leading to jammer removal and increased signal-to-interferenceand-
noise ratio at the input of the correlator. The paper focuses
on jammers with constant modulus that are uniquely described by
their instantaneous frequency characteristics. With this a priori
knowledge, the jammer signal amplitude is restored by projecting
each sample of the synthesized signal to a circle representing its
constant modulus. With the phase matching provided by the least
squares synthesis method and amplitude matching underlying
the projection operation, a significant improvement in receiver
performance/bit-error rates is achieved over the case where no
projection is performed. Software-radio aspects including computational
complexity and processing modes are also discussed. |
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