ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / An acoustic modem employing direct-sequence spread-spectrum (DSSS) signaling is considered with LDPC coding. The underwater acoustic channel is tracked using a Kalman filter
which requires accurate data decisions. To improve KF performance and reduce the overall
error rate, joint iterative LDPC decoding and channel estimation is proposed based on a factor graph and sum-product algorithm approximation. In this scheme, the decoder posterior
log likelihood ratios (LLRs) provide data decisions for the KF. Decoder extrinsic LLRs are
similarly incorporated into the detector LLRs to yield improved priors for decoding. Error
rate simulations of the overall modem are provided for a shallow-water channel model with
Ricean/Rayleigh fading.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/604470 |
| Date | 10 1900 |
| Creators | Iltis, Ronald A. |
| Contributors | University of California |
| Publisher | International Foundation for Telemetering |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Proceedings |
| Rights | Copyright © held by the author; distribution rights International Foundation for Telemetering |
| Relation | http://www.telemetry.org/ |
Page generated in 0.0025 seconds