US 12,231,180 B2
Receiving apparatus
Yosuke Fujino, Musashino (JP); Hiroyuki Fukumoto, Musashino (JP); and Kazunori Akabane, Musashino (JP)
Filed by NIPPON TELEGRAPH AND TELEPHONE CORPORATION, Tokyo (JP)
Filed on Dec. 15, 2023, as Appl. No. 18/542,340.
Application 18/542,340 is a continuation of application No. 17/774,451, granted, now 11,888,538, previously published as PCT/JP2019/044394, filed on Nov. 12, 2019.
Prior Publication US 2024/0187113 A1, Jun. 6, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H04B 17/21 (2015.01); H04B 11/00 (2006.01); H04B 13/02 (2006.01)
CPC H04B 17/21 (2015.01) [H04B 11/00 (2013.01); H04B 13/02 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A receiving apparatus comprising:
M receivers configured to receive signals based on sound waves propagating in water;
M FIR filters configured to perform waveform operation on the signals received by the receivers;
a combiner configured to combine output signals of the M FIR filters; and
a filter coefficient calculator configured to calculate a tap coefficient of the M FIR filters,
wherein the M FIR filters have a tap length that is shorter than a delay spread that is a possible range between a time of arrival of a direct wave and a time of arrival of a delayed wave of the sound waves, where M is an integer greater than or equal to two.