| 摘要 |
PURPOSE:To reduce the influence of outside lights, and also to keep privacy by using a descending signal system as a signal processing system using a spectrum diffusing system. CONSTITUTION:This system is equipped with an encoded signal generator 13 which has the descending signal system and an ascending signal system, and whose descending signal system generates at least an encoded signal, a modulator 12 which modulates the encoded signal, a light emitting element 11 which converts the modulated encoded signal into a light beam, and a light diffusing device 15 which diffuses this light beam. And also, this system is equipped with a light receiving element 19 which is arranged at a distance from this light diffusing device 15, and demodulator 20 which demodulates the signal obtained by this light receiving element 19. That is, the descending signal system is used as the signal processing system using the spectrum diffusing system. Thus, the error of the transmission can be reduced, and the privacy of the signal can be kept, even when the light intensity of the descending signal is weak, and even when an S/N can not sufficiently be obtained because the noise of the outside light is loud. |
