Title:
変調装置、復調装置、および音響信号伝送方法
Document Type and Number:
Japanese Patent JP4361575
Kind Code:
B2
Abstract:
An object is to provide a modulation device, a demodulation device, and a transmission system and acoustic signal transmission method using them which can carry out a synchronization process for data signals without using a carrier frequency for a synchronization signal. A modulation device 3 transmits an acoustic signal superposed with a PN sequence set according to a carrier frequency and a data signal. A demodulation device 9 receives the acoustic signal, determines the PN sequence having the highest maximum correlation value with the acoustic signal in a plurality of PN sequences, detects a symbol synchronization point according to the correlation value between thus determined PN sequence and the acoustic signal, and performs a synchronization process. Thereafter, according to the detected synchronization point and determined PN sequence, an OFDM demodulation processing unit 38 decides the carrier frequency band of the data signal superposed on the acoustic signal and demodulates the data signal.
Inventors:
Yasushi Matsuoka
Ken Yoshimura
Toshiro Kawahara
Ken Yoshimura
Toshiro Kawahara
Application Number:
JP2007151897A
Publication Date:
November 11, 2009
Filing Date:
June 07, 2007
Export Citation:
Assignee:
NTT DoCoMo, Inc.
International Classes:
H04J11/00; H04B1/707; H04B1/7073; H04B11/00; H04L7/00
Domestic Patent References:
| JP7245574A | ||||
| JP9233047A | ||||
| JP10210002A |
Foreign References:
| WO2007043376A1 |
Other References:
中島 悠輔 他,音響OFDMの空中伝送特性,電子情報通信学会技術研究報告,2006年 7月12日,vol.106, no.168,pp.139-144
Attorney, Agent or Firm:
Yoshiki Hasegawa
Shiro Terasaki
Takashi Okiyama
Kenji Fukaishi
Shiro Terasaki
Takashi Okiyama
Kenji Fukaishi
Previous Patent: SUPERCONDUCTIVE JUNCTION ELEMENT
Next Patent: HIGH DIELECTRIC CONSTANT OXIDE SEMICONDUCTOR DEVICE
Next Patent: HIGH DIELECTRIC CONSTANT OXIDE SEMICONDUCTOR DEVICE