摘要:
The present invention relates to α method for controlling α remote unit (10) over α signal line (20), the remote unit (10) being switchable in-between the transmit mode and the receive mode. The remote unit (10) in transmit mode is used for transmission of useful information (26) which is input to the remote unit (10) over the signal line (20) and the remote unit (10) in receive mode is used for reception of useful information (26) which is output by the remote unit (10) over the signal line (20). The method comprises the following steps, providing an activation signal over the signal line (20) before the transmission of useful information (26) over the signal line (20), and detecting said activation signal (27) at the remote unit (10) and switching the remote unit (10) to transmit mode. The invention also relates to a controlling unit and a remote unit for performing said method.
摘要:
In a receiver having an antenna switch (23) which is connected between a receiving section (24) and an antenna (21) for adjusting a received signal so that the received signal has, as a current signal level, one of a first and a second signal level, a switch control section (26) controls an operation of the antenna switch by the use of a current signal level of the received signal and a first and a second reference level which are determined in first and second determining sections (27, 28), respectively. In order to detect the current signal level, a signal level detection circuit (25) is connected to the antenna switch. It is preferable that a signal level holding circuit (34) is connected between the signal level detection circuit and the switch control section and is for holding the current signal level during a predetermined time duration.
摘要:
A voice controlled speaker microphone of a wireless intercom, wherein while the wireless intercom is transmitting voices, the bias voltage of the manual switch and condenser microphone is divided to give a current of 0.6mA to 1mA and then, while receiving voices, the speaker's driving voltage is multiplied and rectified to give a current of 1mA to 30mA, then provided to charge the battery and supply the voice-controlled circuit.
摘要:
In a speech signal transmitting system which effect VOX control, the transmitting side transmits a postamble and the succeeding background noise coded data at regular time intervals in a silent duration subsequent to a speech-active duration. At the receiving end, upon each reception of the background noise coded data in the silent duration, power information and prediction coefficients contained in the coded data are stored in a background noise parameter memory (22). A random pattern, generated by a random pattern generator (23), is used as a residual signal, and a background noise is synthesized by a background noise synthesizer (24) on the basis of the power information and prediction coefficients read out of the background noise parameter memory for each frame. In the speech-active duration a decoded speech is output, and in the silent duration the synthesized background noise is output.
摘要:
Un premier microphone (1) réagissant essentiellement à la parole et un deuxième microphone (11) réagissant essentiellement au bruit sont reliés chacun à une entrée (7, 8) d'un comparateur (9) par l'intermédiaire d'un amplificateur (3, 13), d'un redresseur (5, 15) et d'un filtre passe-bas (6, 16). Les degrés d'amplification pour les sensibilités données des microphones sont déterminés de telle manière que les tensions d'entrée du comparateur (9) soient égales lorsque le rapport entre la tension de parole et la tension de bruit suffit à l'intelligibilite de la parole. Le comparateur (9) met à l'état une bascule monostable (21) lorsque sa tension d'entrée provenant de la tension de parole dépasse la tension d'entrée provenant du bruit. A ce moment, le canal téléphonique est enclenché et est maintenu à l'état enclenché jusqu'à ce que la bascule monostable (21) retourne à l'état de repos. Lorsque le canal téléphonique est enclenché un signal sonore est délivré à l'écouteur (36) afin d'avertir l'utilisateur que le canal téléphonique est enclenché. Peu avant le retour de la bascule (21) à l'état de repos le signal sonore est interrompu périodiquement pour indiquer que, si le canal téléphonique doit rester enclenché, il faut poursuivre immédiatement la communication respectivement parler plus fort.
摘要:
A method for detecting the presence of a transmission signal in a wireless spectrum channel. The frequency of a signal is converted from a first frequency to a second frequency. The signal with the second frequency is filtered to remove signals that are not within the band of the second frequency. An averaged periodogram of the signal is calculated. A value of the averaged periodogram is compared to a threshold. The presence of the transmission signal is detected, if the value of the averaged periodogram exceeds the threshold.