Abstract:
Controlled by a signal level produced by a microphone (12), a noise suppressing circuit (25) supplies a first attenuator (16) with a local level which is equal to the signal level and is suppressed to a predetermined output level when the signal level is lower and higher than a predetermined input level. Cooperating with a drive level produced by a second attenuator (17) to drive a loudspeaker (13), the local level makes a comparator unit (21-23) produce a control signal for making the first attenuator give smaller and greater amounts of attenuation to the signal level with the drive level rendered by the second attenuator low and high when positive and negative values are had, respectively, by an input difference equal to the local level less the drive level. Preferably, the local level is suppressed by a level difference had by the signal level above the predetermined input level.
Abstract:
This invention has as its object to reduce power consumption of dependent stations with low frequency of communication by controlling communications of the control station in a network. According to this invention, a control station communicating with dependent stations comprises a classification unit configured to classify the dependent stations connected to the control station into a plurality of groups; a first transmission unit configured to transmit first broadcast-frame to the dependent stations classified into first group; and a second transmission unit configured to transmit second broadcast-frame to the dependent stations classified into second group with lower frequency of communication compared to the first group, wherein the second transmission unit transmits the second broadcast-frame with a lower transmitting frequency compared to the first broadcast-frame transmitting frequency of the first transmission unit.
Abstract:
A communication apparatus determines a hibernation period on the basis of the amount of an offset in beacon period start timing among multiple beacon groups. The communication apparatus is placed in a hibernation status in accordance with the determined hibernation period. Thus, an offset in beacon period start timing among the beacon groups that would occur while the device is in hibernation can be prevented and the need for merging beacon groups and decrease in data rate during such merging are prevented.
Abstract:
In a surface acoustic wave apparatus, a surface acoustic wave element for obtaining a convolution signal is housed in a recess of a substrate. Since the surface acoustic wave element is housed in the recess of the substrate in this surface acoustic wave apparatus, the apparatus can be compactified. This effect of compactification is remarkable, because the surface acoustic wave element has an output electrode for obtaining the convolution signal and thus originally has a big element size. When a laminate substrate is used as the substrate, a configuration for effectively using surfaces of respective layers may be arranged in such a manner that output wiring of the convolution signal is separately formed in the layers. This further enhances the effect of compactification. There are further disclosed a spread spectrum signal receiver using the above surface acoustic wave apparatus for receiving a spread spectrum signal, and a spread spectrum communication system using the spread spectrum signal receiver.
Abstract:
A device for detecting the position of an information recording or reproducing head relative to a recording medium; the head is relatively rotatable around a first axis with respect to the recording medium, and rotatable around a second axis parallel to the first axis. The device includes an autocollimator for measuring a relative positional relationship of the head substantially along the direction of the rotation around the second axis, a rotating table on which either the combination of the recording medium and the head or the autocollimator is mounted to activate the rotational movement substantially around the second axis, and a control unit. The control unit rotates the rotating table in response to the obtained position of the head with respect to the recording medium. According to the measurement result by the autocollimator, the control unit accomplishes a relative positional controlling in which a relative positional relationship between the autocollimator and the head is kept constant. As a result, a compact and high-accuracy head positioning device is achieved.
Abstract:
Novel benzo[.alpha.]phenazine derivatives of the formula ##STR1## wherein R.sup.1 is hydrogen, halogen, methyl, hydroxyl or alkoxy, R.sup.2 is --COOR.sup.5 (wherein R.sup.5 is hydrogen, straight or branched chain alkyl, cycloalkyl having 3-6 carbon atoms, benzyl or phenyl) or ##STR2## wherein R.sup.6 and R.sup.7 are the same or different and are each hydrogen or lower alkyl, or R.sup.6 and R.sup.7 together with the nitrogen atom to which they are attached form pyrrolidine or piperidine), R.sup.3 and R.sup.4 are the same or different and are each hydrogen or lower alkyl, and n is an integer of 2 or 3, and the salts thereof are disclosed. These compounds have antitumor activity in mammals.
Abstract:
This invention provides a communication system, a communication apparatus, a control method of the communication apparatus, and a computer-readable storage medium, which enable to increase the reliability of relay transmission and suppress redundant transmission.
Abstract:
A communication apparatus includes a plurality of descramblers for subjecting a second header portion of a received frame to descrambling processing using pseudo-random sequences that differ from one another; a plurality of syndrome arithmetic units for performing a syndrome calculation, which is in accordance with a cyclic redundancy check code, with respect to headers descrambled by respective ones of the plurality of descramblers, and an error correction unit for selecting a header that has been descrambled by one descrambler among the plurality of descramblers as a receive header, in accordance with syndrome values calculated by respective ones of the plurality of syndrome arithmetic units.
Abstract:
An SSID and an encryption key of a wireless LAN apparatus of computer peripheral equipment are calculated based on a manufacturer's serial number of the computer peripheral equipment to be stored in the wireless LAN apparatus of the computer peripheral equipment. On the other hand, for an SSID and an encryption key of a computer wirelessly connected to the computer peripheral equipment, when driver software of the computer peripheral equipment is installed, a user inputs the manufacturer's serial number of the computer peripheral equipment, and the SSID and the encryption key of a wireless LAN apparatus are calculated on the computer to be stored in the wireless LAN apparatus of the computer. Thus, the same SSID and encryption key as those of the computer peripheral equipment can be set in the computer.
Abstract:
A communication apparatus includes a plurality of descramblers for subjecting a second header portion of a received frame to descrambling processing using pseudo-random sequences that differ from one another; a plurality of syndrome arithmetic units for performing a syndrome calculation, which is in accordance with a cyclic redundancy check code, with respect to headers descrambled by respective ones of the plurality of descramblers, and an error correction unit for selecting a header that has been descrambled by one descrambler among the plurality of descramblers as a receive header, in accordance with syndrome values calculated by respective ones of the plurality of syndrome arithmetic units.