Appeal point
Handling unsteady Doppler shift in underwater acoustic communication
Summary
Problems to be solved in underwater acoustic digital communication include interference due to multipath waves, noise, limitation of usable band, limitation of transmission level that can be transmitted by a transmitter. Among them, a big problem is the influence of Doppler shift due to movement of the communication device (transmitter, receiver) on the transmitting side or the receiving side.
The present invention is a receiver efficiently compensating the influence of Doppler shift in a mobile communication system, and has the following configuration.
1) Doppler estimator 11 for estimating the Doppler shift frequency of the received signal.
2) A multiplier 12 that detects the received signal based on the carrier frequency of the received signal and the Doppler shift frequency estimated by the Doppler estimator.
3) A timing corrector 161 that corrects the timing for extracting the symbol of the detected reception signal so as to follow the Doppler shift.
4) A symbol extractor 14 that extracts received symbols from the detected signal at the timing corrected by the timing corrector.
5) An adaptive equalizer 15 is provided for estimating and determining a symbol from the received symbol extracted by the symbol extractor.
The present invention is a receiver efficiently compensating the influence of Doppler shift in a mobile communication system, and has the following configuration.
1) Doppler estimator 11 for estimating the Doppler shift frequency of the received signal.
2) A multiplier 12 that detects the received signal based on the carrier frequency of the received signal and the Doppler shift frequency estimated by the Doppler estimator.
3) A timing corrector 161 that corrects the timing for extracting the symbol of the detected reception signal so as to follow the Doppler shift.
4) A symbol extractor 14 that extracts received symbols from the detected signal at the timing corrected by the timing corrector.
5) An adaptive equalizer 15 is provided for estimating and determining a symbol from the received symbol extracted by the symbol extractor.
Schematic image
Application
Acoustic communication with small vessels that are subject to oscillation
Relational patent
Item name
:
Receiving device and receiving method
Filing date
:
2014-05-23
Inventor(s)
Takuya Shimura
Hiroshi Ochi
Yoshitaka Watanabe