Title :
Performance of a nonlinear adaptive SBS-MAP detector using soft-statistics for digital transmissions over HF channels
Author :
Baccarelli, E. ; Cusani, R. ; Galli, S.
Author_Institution :
INFOCOM Dept., Rome Univ., Italy
fDate :
7/1/2000 12:00:00 AM
Abstract :
The effectiveness of the adaptive maximum a posteriori (MAP) receiver in Cusani and Mattila is verified for digital HF links between mobile and/or fixed units. Following Cusani and Mattila (1998), a suitable MAP algorithm is employed to compute symbol-by-symbol (SBS) the a posteriori probabilities (APPs) of the channel state; from these, the detected data stream is obtained. The same APPs are employed by an adaptive nonlinear Kalman-like filter to estimate recursively the time-varying channel with fast convergence and good tracking properties, overcoming the delay problem suffered by conventional adaptive MLSE-VA detectors. Computer simulations allow to compare the adaptive SBS-MAP with other receivers (DFE, MLSE) and verify its effectiveness in the HF environment
Keywords :
adaptive Kalman filters; adaptive signal detection; convergence; digital radio; land mobile radio; maximum likelihood estimation; nonlinear filters; radio receivers; recursive estimation; statistical analysis; time-varying channels; tracking filters; HF channels; SBS-MAP; a posteriori probabilities; adaptive maximum a posteriori receiver; adaptive nonlinear Kalman-like filter; channel state; convergence; delay; detected data stream; digital HF links; digital transmissions; nonlinear adaptive SBS-MAP detector; performance; soft-statistics; symbol-by-symbol approach; time-varying channel; tracking; Baseband; Brillouin scattering; Delay estimation; Detectors; Fading; Frequency; Low pass filters; Military aircraft; Military communication; Signal processing;
Journal_Title :
Vehicular Technology, IEEE Transactions on
