50 likes | 197 Views
Multichannel Decision Feedback Equalization in underwater sensor networks. Deepthi Chander (05407003) Pallavi Manohar (05407002). Features. Underwater acoustic channels-severely bandlimited Multipath –challenging issue Digital transmission-multipath causes ISI
E N D
Multichannel Decision Feedback Equalization in underwater sensor networks Deepthi Chander (05407003) Pallavi Manohar (05407002)
Features • Underwater acoustic channels-severely bandlimited • Multipath –challenging issue • Digital transmission-multipath causes ISI • Multichannel equalizer-exploits spatial diversity of multipath • Decision Feedback Equalizer (DFE) removes ISI from previously estimated symbols • Phase synchronization and equalization performed jointly-Recursive least Squares (RLS) algorithm used for fast convergence
1/Ts 1/Ts 1/T 1/T feedforward filter 1 feedforwrd filter K x x Input K Input 1 . . . Carrier correction K Carrier correction1 Estimated symbol Symbol decision + Σ - feedback filter - + Adaptive Algorithm (RLS) error 2nd order PLL Training symbol Phase Coherent Multichannel Decision Feedback Equalizer (DFE)
1/Ts x Input 1 . . . Estimated symbol Carrier correction1 Multichannel DFE Spatial pre-combiner 1/Ts x Input K Carrier correction K Reduced Complexity Multichannel DFE