Experimental assessment of sparse channel estimations for passive-phase conjugation communications

This paper investigates sparse channel estimations to improve the performance of passive-phase conjugation (PPC) communications. PPC processing achieves pulse compression for time delayed arrivals at the receiver. This property is used for underwater communications with a reduced computational load. The channel estimation is required by PPC. In multipath channels, the sparse channel estimations can be used to improve the communication performance. The dominant arrivals are estimated by matching pursuit (MP) processing for PPC processing and the remained arrivals are treated as zeros. Using experimental data collected in a range dependent acoustic channel, MP processing is assessed in improving the performance of PPC communications.