With Demodulator Patents (Class 455/21)
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Publication number: 20030129999Abstract: A wireless relay system (1) comprises a wireless camera (11) and a reception relay station (12). The reception relay station (12) comprises a plurality of external reception units (13) arranged at spatially different positions and an internal reception unit (14). Each reception section (16) in the internal reception unit (14) demodulates a signal received in the external reception unit (13) and outputs a transport stream. At this time, each reception section (16) sets an error indicator flag to 1 for a TS packet causing a transmission error which exceeds the error correction capability. A TS synthesizer section (17) in the internal reception unit (14) completely synchronizes a plurality of input transport streams by referencing synchronization bytes, PID, and CC values, and selects to output a TS packet having the error indicator flag not set to 1.Type: ApplicationFiled: September 16, 2002Publication date: July 10, 2003Inventors: Yasunari Ikeda, Norishisa Shirota, Hideyuki Matsumoto
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Publication number: 20030119444Abstract: Cell search synchronization in spread spectrum communications systems using primary and second synchronization codes with symbol partitioning for shorter coherent combinations (despreading) which are combined non-coherently, and Fourier transform analysis automatically adjusts for phase rotation of the despread sub-symbols.Type: ApplicationFiled: October 30, 2002Publication date: June 26, 2003Inventor: Hirohisa Yamaguchi
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Publication number: 20030114103Abstract: A repeater system for transmitting and receiving RF signals to and from an area obstructed by a mountain, a building, etc. One antenna is linked to the base station antenna of, for example, a cell in a cellular network, and another antenna is directed to the obstructed area. Signals are received by one antenna from the base station antenna and digitally separated into a number of different frequency channels. The separated channels are then transmitted by the other antenna into the obstructed area to mobile users. Also, signals from the mobile users are received by one of the antennas and similarly digitally separated into different frequency channels and transmitted to the base station antenna for delivery to a communication network.Type: ApplicationFiled: December 19, 2001Publication date: June 19, 2003Applicant: RADIO FREQUENCY SYSTEMS, INC.Inventors: Brian J. Dinkel, Paul A. Carney
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Publication number: 20020146980Abstract: A wireless architecture is disclosed based on the use of two separate air interfaces on two separate sets of uplinks and downlinks. In particular, the multiple air interface architecture of the invention incorporates a re-radiator that employs two different air interface protocols. One air interface protocol is used for “backhaul” reception and transmission to the serving network base station, and is deployed between the fixed network base station and the re-radiator. This air interface protocol is optimized for transmission over a long distance and for sharing among multiple users. A second air interface protocol is used for local re-radiation between the re-radiator and a served end user device. This second air interface is optimized for very short distances. The reradiator itself is placed at a fixed location allowing it to take advantage of antenna directionality and antenna gain, and also to meet certain requirements regarding fixed terminals.Type: ApplicationFiled: April 4, 2001Publication date: October 10, 2002Inventors: Max Aaron Solondz, Krishnamurthy Sreenath
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Patent number: 6243560Abstract: The present method for reducing latency in satellite communication includes the steps of applying, at a first earth terminal, a discriminator to user data. The discriminator delineates action data and forward data, thereby forming delineated user data. The action data represents data to be processed on board a satellite, while the forward data represents data to be forwarded through the satellite without processing. At the satellite, the delineated user data is partitioned into the action data and the forward data. The satellite then processes the action data to form processed action data and transmits, if necessary, the processed action data from the satellite. During processing of the user data, the satellite may generate result data in response to the action data and may transmit the result data alone or appended to the processed action data. Furthermore, the satellite may store a world model in a memory onboard the satellite.Type: GrantFiled: October 30, 1998Date of Patent: June 5, 2001Assignee: TRW Inc.Inventor: Keith R. Jenkin
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Patent number: 6157811Abstract: Radiocommunication systems and methods for minimizing co-channel interference are disclosed. The systems and methods are applicable to, for example, landmobile communications, satellite communication systems and hybrids thereof. Signal processing using matrix models of received and transmitted signals provides for minimized interference.Type: GrantFiled: February 16, 1996Date of Patent: December 5, 2000Assignee: Ericsson Inc.Inventor: Paul W. Dent
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Patent number: 6115581Abstract: Apparatus for communication using multiple radio processing modules is disclosed herein. The apparatus for communication mentioned above receives a first radio signal and a second radio signal from a source to acquire a first information and a second information. The first radio signal and the second radio signal is within a first frequency range and a second frequency range respectively. The first message signal and the second message signal are of a baseband range. The first information and the second information are carried by the first message signal and the second message signal respectively. The apparatus for communication mentioned above includes the following devices. A first radio processing module that transfer the first radio signal to generate the first message signal. A second radio processing module that transfers the second radio signal to generate the second message signal.Type: GrantFiled: August 17, 1998Date of Patent: September 5, 2000Assignee: Eten Information System Co., Ltd.Inventor: Hsi-Chi Wu
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Patent number: 6108517Abstract: Methods and apparatus for receiving adjacent channel signals wherein adjacent channel interference effects are minimized through joint demodulation of the adjacent channel signals. A channel associated with each signal and each corresponding frequency band is estimated and used to form joint branch metrics for joint sequence estimation. In an exemplary embodiment, a baseband processor receives baseband samples corresponding to at least one carrier frequency, and then jointly demodulates at least two information streams corresponding to different carrier frequencies in dependence upon the received baseband samples. In another embodiment, a joint channel estimator receives at least two baseband sample streams, each stream corresponding to a different frequency band, and jointly estimates medium responses for each of at least two information signals which were transmitted in different frequency bands.Type: GrantFiled: July 28, 1997Date of Patent: August 22, 2000Assignee: Ericsson Inc.Inventors: Huseyin Arslan, Someshwar C. Gupta, Gregory E. Bottomley, Sandeep Chennakeshu
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Patent number: 6078787Abstract: An antenna system (100) at a mobile communication station (150) comprises a main unit (101) which comprises at least one network antenna (102), a relay antenna (103) for communication with the mobile station (150) and an interface unit (104) connected to the network antenna (102) and the relay antenna (103). The antenna system (100) also comprises a local antenna (105) in the mobile communication station (150) for communication with the relay antenna (103) in the main unit (101). The main unit (101) is attachable to and detachable from the mobile communication station (150), while at the same time the relay antenna (103) and the local antenna (105) lack galvanic contact. In an attached state, the relay antenna (103) and the local antenna (105) are electrically connected to each other by means of a capacitive connection, and in a detached state, the relay antenna (103) and the local antenna (105) are electrically connected to each other by an electric far-field connection.Type: GrantFiled: May 15, 1998Date of Patent: June 20, 2000Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Henry Schefte, deceased, Sven Anders Gosta Derneryd, Jan Staffan Reinefjord
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Patent number: 5963847Abstract: A booster system for transmitting a received wave after amplifying it comprises a receiving antenna section, a carrier combining section, a transmitting section, a transmitting antenna section and a parameter control section. The carrier combining section multiplies a canceling signal by a cancel parameter to obtain a replica signal, then combines it with a received signal in at least one of the radio frequency band, the intermediate frequency band and the base band, and derives a combined base band signal from the combined signal. The transmitting section generates a send signal and a canceling signal by using a signal demodulated through the demodulation of the combined base band signal. Based on the combined base band signal and the canceling signal, the parameter control section determines a canceling parameter such that the power of the combined base band signal is reduced, the parameter being provided to the carrier combining section.Type: GrantFiled: June 25, 1997Date of Patent: October 5, 1999Assignee: NTT Mobile Communications Network Inc.Inventors: Kazuhito Ito, Hiroshi Suzuki, Manabu Nakada, Yoshio Ebine
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Patent number: 5903592Abstract: A radio transmission system is provided which includes a master station and a plurality of series connected substations connected to the master station via a radio channel. First receiving unit receives a plurality of modulated waves which have been modulated by means of spread spectrum. Accordingly, demodulating unit may only have a capability to process a baseband signal destined therefor, in order to demodulate the modulated wave destined therefor from among the modulated waves. On the other hand, the modulated waves received by the first receiving unit are transmitted by first transmitting unit in a first transmission direction to an adjacent substation, and thus are relayed as they are without being demodulated or modulated in the middle.Type: GrantFiled: September 30, 1996Date of Patent: May 11, 1999Assignee: Fujitsu LimitedInventor: Eiji Itaya
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Patent number: 5890055Abstract: A wireless communications system includes a number of clusters of repeaters wherein all repeaters within a cluster arc connected to a common hub via respective millimeter-wave radio links. Wireless signals received by the repeaters from end-user devices are transparently carried by the millimeter-wave radio links to respective hubs that act as concentrators for the repeaters. The hubs may be linked to a wireless network base station (in an outdoor setting) or alternatively to a server or a PBX (in an indoor environment) via a high-speed transmission facility, such as a fiber optic cable that is thus shared by all the repeaters.Type: GrantFiled: July 28, 1995Date of Patent: March 30, 1999Assignee: Lucent Technologies Inc.Inventors: Ta-Shing Chu, Martin V. Clark, Peter Frank Driessen, Vinko Erceg, Lawrence Joel Greenstein, Robert Stephen Roman, Anthony Joseph Rustako, Jr., Giovanni Vannucci
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Patent number: 5774789Abstract: A system and method for distribution of RF communication signals. First RF communication signals are downconverted in a first signal processing subsystem and transmitted to a second signal processing subsystem via twisted-pair cable. The downconverted first RF communication signals are upconverted at the second signal processing subsystem to provide recovered first RF communication signals, and the recovered first RF communication signals are transmitted via an antenna. Operating power for the second signal processing subsystem is provided from the signal processing subsystem, and the second signal processing subsystem determines the occurrence of an event and transmits autonomous information signals thereabout to the first signal processing subsystem.Type: GrantFiled: December 14, 1995Date of Patent: June 30, 1998Assignee: Allen Telecom Inc.Inventors: Erik van der Kaay, George S. Dubovsky
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Patent number: 5768680Abstract: The instant invention is an electronic audio monitor and recording device designed to be worn upon the person, in connection with audience research systems, for purposes of capturing special identifying signals embedded in audio and video programs, appending the date and time each signal is received, and recording and retaining the data until it is transferred for further processing.Type: GrantFiled: May 5, 1995Date of Patent: June 16, 1998Inventor: C. David Thomas
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Patent number: 5734962Abstract: A VSAT satellite communications network utilizes parallel concatenated coding on its inbound or outbound links, or both. For short data blocks, nonrecursive systematic tail-biting convolutional codes are used. For longer data blocks, recursive systematic convolutional codes are used. These parallel concatenated coding techniques are used in conjunction with spread-spectrum modulation to provide a VSAT communications system which meets FCC regulations on the total power spectral density of transmitted signals as well as mitigates interference from adjacent satellites.Type: GrantFiled: July 17, 1996Date of Patent: March 31, 1998Assignee: General Electric CompanyInventors: Stephen Michael Hladik, William Alan Check, Brian James Glinsman, Robert Fleming Fleming, III
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Patent number: 5634191Abstract: An RF repeater arrangement for exchanging transmit and receive signals between a handset and a base station in a wireless telephone system automatically compensates for attenuation losses. The RF repeater arrangement includes first and second RF repeater parts connected by a signal conduit, the first part interfacing with the base station and having a signal level detector for detecting the level of the transmit signal, a microprocessor controller for quantizing and encoding the signal level detected by the level detector and a modulator for modulating the signal level data and outputting the modulated signal level data to the signal conduit.Type: GrantFiled: October 24, 1994Date of Patent: May 27, 1997Assignee: PCS Microcell International, Inc.Inventor: Andrew Beasley
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Patent number: 5485464Abstract: A communication protocol or method that provides for terminal access, data flow, call monitoring and terminal polling, and call termination between user terminals connected to a high data rate satellite communication system. An "Aloha" random access channel that forms part of a bent-pipe architecture is used in conjunction with orderwire uplink and downlink channels to permit the system to cleanly and simply establish its data links and thus provide terminal access. A network control center is used to assign a source user terminal to uplink and downlink channels. After the communication link is established, uplinked data is demodulated, and routed to every downlink beam where it is multiplexed with other data channels, then remodulated and downlinked to every user terminal. The orderwire uplink is only from the network control center to the satellite relay system, and uses the channel without demodulation and remodulation.Type: GrantFiled: October 21, 1993Date of Patent: January 16, 1996Assignee: Hughes Aircraft CompanyInventors: Andrew L. Strodtbeck, Jennifer L. Vollbrecht
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Patent number: 5455960Abstract: A satellite communications scheme for enhancing the communications system with existing satellites is disclosed. The existing satellites include a transponder having a phase locked loop phase demodulator at the front end thereof. The present invention discloses a technique wherein the phase demodulator is locked by transmitting a relatively high-power carrier from the ground to the satellite transponder. Once the demodulator has been locked, remote ground terminals operating at much lower power levels can access the satellite transponder by transmitting at carrier frequencies spaced apart from the primary high-power carrier. These are down-converted by the transponder phase demodulator and then typically amplitude and frequency limited before being remodulated and retransmitted.Type: GrantFiled: January 16, 1992Date of Patent: October 3, 1995Assignee: Harris CorporationInventors: Guy M. Pelchat, Stephen G. Powers, Raymond F. Cobb, Robert C. Hildebrand
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Patent number: 5416449Abstract: An improved modulator circuit for mixing a modulation signal with a carrier signal includes first and second harmonic mixers which are operative to produce modulated output signals at an output frequency corresponding to both the sum and the difference of the modulation signal frequency and the even harmonic frequencies of the carrier signal frequency. In one configuration employing a 90.degree. hybrid, the output signals of the harmonic mixers are combined to produce a single sideband modulated output signal. A novel harmonic mixer circuit is also provided along with demodulator circuits and methods of modulating and demodulating modulation signals.Type: GrantFiled: May 23, 1994Date of Patent: May 16, 1995Assignee: Synergy Microwave CorporationInventor: Shankar R. Joshi
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Patent number: 5349463Abstract: An optical radio system includes a host device, an end device, and a repeater. The host device and the end device communicate with each other via the repeater by use of optical radio. The repeater includes a section for receiving a first light signal from one of the host device and the end device, a section for converting the received first light signal into a first electric signal, a section for frequency-converting the first electric signal into a second electric signal, and a section for generating a second light signal in response to the second electric signal and transmitting the generated second light signal. The repeater also includes a section for demodulating one of the first electric signal and the second electric signal into a baseband signal, a section for detecting a quality of the baseband signal, and a section for enabling transmission of the second light signal only when the detected quality of the baseband signal is equal to or greater than a predetermined quality.Type: GrantFiled: May 28, 1993Date of Patent: September 20, 1994Assignees: Victor Company of Japan, NTT Data Communications Systems CorporationInventors: Kazutoshi Hirohashi, Hiroshi Horii, Hideo Koike, Yoshiaki Yunoki, Tetsuo Fukasawa, Susumu Katayama, Akio Yoshikawa, Keishi Ushijima, Takaaki Takeda, Takeshi Nomoto, Michio Kikuta, Shunichi Shichijo, Yoshiki Iwasaki
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Patent number: 5301355Abstract: An infrared remote control signal is entered into a receiving circuit where it is converted into an electrical, modulated signal made up of a carrier and a command signal. The modulated input signal is sent to a control signal output circuit where it is filtered to send only the carrier of the remote input signal to a frequency-voltage conversion circuit. The frequency-voltage conversion circuit generates a control DC voltage according to the carrier frequency. The control DC voltage changes the pass band characteristic of a voltage-controlled filter in such a manner that the voltage-controlled filter selectively passes the desired fundamental frequency component and harmonic components of the carrier signal. The voltage-controlled filter also passes the command signal component. Thus, at the output of the voltage-controlled filter is obtained a modulated output signal whose carrier frequency is varied from that of the modulated input signal.Type: GrantFiled: July 12, 1990Date of Patent: April 5, 1994Assignee: Pioneer Electronic CorporationInventors: Hiroshi Koinuma, Hiroshi Terashima
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Patent number: 5023931Abstract: A wireless local television transmission system with related methods, apparatus, and components. There is a source of a video signal to be viewed at a remote location such as a TV camera, cable select box, antenna, or VCR. An up converter is connected to the source for shifting the video signal to a frequency above the normal television bands. A transmitter is connected to the up converter for transmitting the video signal at the shifted frequency. A receiver is disposed at the remote location for receiving the transmitted video signal. A down converter is connected to the receiver for shifting the video signal back down to a frequency within the normal television bands and identified with a known channel. Finally, conventional television set functions are connected to the down converter for processing and displaying the video signal on the known channel.Type: GrantFiled: December 27, 1989Date of Patent: June 11, 1991Assignees: Jerry Iggulden, Donald StreckInventors: Donald A. Streck, Jerry R. Iggulden
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Patent number: 5020131Abstract: In a satellite communications system, satellite channels are divided into groups of successively adjacent channels which are covered by a range of frequency drifts caused by a satellite transponder and the channels of each group are assigned unique words of different bit patterns. Modulation systems of an earth station are associated respectively with demodulation systems of distant earth station via the respective satellite channels. A unique word is transmitted from each modulation system together with an information signal and received by an associated demodulation system of the distant earth station. A variable frequency carrier is synthesized in the demodulation system to demodulate the received signal to recover the information signal and the unique word. The recovered unique word is used to establish the frame start timing and the variable frequency carrier is controlled in response to the unique word to tune in the demodulation system to the desired satellite channel.Type: GrantFiled: January 10, 1989Date of Patent: May 28, 1991Assignee: NEC CorporationInventor: Yasuhito Isoe
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Patent number: 4972346Abstract: A high-frequency signal booster which has at least one channel unit including a down-converter for converting input signals into intermediate-frequency signals and an up-converter for converting time into output signals. The respective up- and down-converters are separately equipped with station-originating signal oscillators. Further, the station-originating signal oscillator provided for the up-converter has a function of effecting the modulation with out-of-voice-band signals.Type: GrantFiled: March 23, 1988Date of Patent: November 20, 1990Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Minori Kawano, Koji Mihashi
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Patent number: 4829588Abstract: A transceiver and method of controlling the automatic retransmission of a radio frequency commmunications signal in which a pilot tone within the radio frequency communications channel bandwidth but above the band of frequencies necessary for intelligence is phase modulated at a frequency below the frequency band of the intelligence and combined with the intelligence for transmission over a first frequency communication link. When received, the presence of the pilot tone and the modulation is detected, compared with predetermined standards and utilized to control the application of the demodulated intelligence to a second communication link. After establishing the second communication link, the predetermined standards utilized to control the application of the intelligence to the second communication link are relaxed.Type: GrantFiled: August 25, 1981Date of Patent: May 9, 1989Assignee: Harris CorporationInventor: Dean Keyser
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Patent number: 4733223Abstract: Apparatus for monitoring the status of and controlling faults at remotely-located components in a single line communications system wherein return data signals from the components are transmitted in the 50 kHz to 200 kHz range, and coupled to the low pass filters commonly used to bypass the active components, thereby permitting the return of signals to the system head-end.Type: GrantFiled: March 26, 1987Date of Patent: March 22, 1988Inventor: William C. Gilbert
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Patent number: 4701935Abstract: A digital microwave radio repeater using the same carrier frequency for the transmitter and the receiver carriers for improving the frequency utilization efficiency. The transmitter-to-receiver interference signal is cancelled by producing an estimated-interference signal of the interference signal from the digital baseband signal by the use of a transversal filter and by subtracting the estimated-interference signal from the received signal. The estimated-interference signal is also produced by frequency shifting a digital modulated signal in the transmitter. The transmitter carrier frequency is locked to the receiver carrier frequency by the use of a phase-locking technique, so that the interference signal is reduced.Type: GrantFiled: January 9, 1986Date of Patent: October 20, 1987Assignee: NEC CorporationInventor: Junji Namiki
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Patent number: 4682368Abstract: A mobile radio data communication system wherein a fixed unit transmits an operation command code sequence for an instruction to an operator having a portable unit. A speech synthesizer of the portable unit is responsive to the command code sequence to generate a speech signal which is audible to the operator. In response to the audible instruction, the operator replies by voice, and the speech signal is supplied to a speech recognition circuit which sends a code associated with the speech signal to the fixed unit.Type: GrantFiled: March 26, 1985Date of Patent: July 21, 1987Assignee: NEC CorporationInventor: Tsutomu Takahashi
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Patent number: 4656252Abstract: Amidobiotin extender compounds useful, for example, in avidin-biotin multiple-layering process, which compounds include caproylamidobiotin-NHS ester, caproylamidobiotin-horse radish peroxidase, caproylamidobiotinribonuclease and caproylamidobiotin-alkaline phosphatase (B-ALP).Type: GrantFiled: June 4, 1984Date of Patent: April 7, 1987Inventor: Roger W. Giese
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Patent number: 4506383Abstract: In satellite communication systems it is often necessary to relay the signal between terminal stations and the satellite through ground relay stations remote from the terminal stations. Normally, in systems using composite multi-carrier signals for transmission through the satellite, the composite multi-carrier signals are reduced to baseband in the ground relay station prior to retransmission. To reduce the amount of equipment and the cost of such a ground relay station, a method and apparatus for relaying the composite multi-carrier signal through the ground relay station without reducing it to baseband in the ground relay station is provided. Thus, with this arrangement, the composite multi-carrier nature of the signal is preserved throughout the ground relay station.Type: GrantFiled: January 4, 1980Date of Patent: March 19, 1985Assignee: Harris CorporationInventor: William E. McGann
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Patent number: 4471491Abstract: A service channel signal transmission system in which a service channel signal is constantly fed to at least two radio channels in parallel. Each intermediate repeater station has a service channel demodulator which is constantly connected to either one of the radio channels. A combining and switching circuit automatically switches over the service channel demodulation to the other radio channel in response to an alarm output which indicates an abnormality in a received signal at a receiver associated with the one radio channel. The service channel is completely switched from one to the other without resorting to line switchover control signals from terminal stations.Type: GrantFiled: February 1, 1983Date of Patent: September 11, 1984Assignee: Nippon Electric Company, Ltd.Inventors: Akira Abe, Hiromi Hashimoto, Toshiyuki Takenaka, Koyo Taniguchi
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Patent number: 4253191Abstract: The present invention discloses a straight-through-repeater which relays a frequency-modulated microwave signal. The straight-through-repeater is basically comprised of a phase-locked loop circuit located between receiving and transmitting antennas of the repeater. The phase-locked loop circuit has a demodulating capability for reproducing a baseband signal, a power amplifying capability, a very narrow filtering capability, an automatic gain controlling capability and an amplitude limiting capability. The repeater is further comprised of a means for suppressing a step-out of synchronism occurring in the phase-locked loop circuit.Type: GrantFiled: February 26, 1979Date of Patent: February 24, 1981Assignee: Fujitsu LimitedInventor: Takuro Oguchi
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Patent number: 4198600Abstract: The present invention discloses an FM microwave radio frequency repeater using the straight-through system for relaying signals of a plurality of channels having different carrier frequencies, each of the channels including an auxiliary channel. The system according to the invention is characterized in that the auxiliary channel has the signals thereof demodulated through frequency discrimination of a difference frequency signal obtained by mixing together two received microwaves.Type: GrantFiled: May 25, 1978Date of Patent: April 15, 1980Assignee: Fujitsu LimitedInventors: Takuro Oguchi, Hajime Masuda