Multichannel bidirectional equalization for underwater acoustic communication based on passive phase conjugation

This paper presents a receiver structure which exploits spatial diversity by adaptive multichannel combining, which improves the performance of passive time reversal communications realized by passive phase conjugation (PPC). The bidirectional decision feedback equalizer (BiDFE) replaces the classical DFE to eliminate inter-symbol interference (ISI). The presented structure takes advantage of pulse compression, the difference in error propagation between the forward DFE and backward DFE, and performs adaptive multichannel combining. Simulation shows the porposed structure has a better performance than other existing structure.