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51.发明专利
公开(公告)号：CA2078705C
公开(公告)日：1996-10-29
申请号：CA2078705
申请日：1992-09-21
Applicant: NEC CORP
Inventor： ICHIYOSHI OSAMU
IPC: H04L27/227 , H04L27/00 , H04L27/22 , H04L27/233 , H03K9/04
Abstract: In order to coherently demodulate an incoming multiphase PSK analog signal irrespective of large frequency deviation, an automatic frequency feedback loop is provided. An analog baseband signal is generated by multiplying the IF analog signal by a local signal and then is converted into the corresponding digital baseband signal. A multiplier multiplies the digital baseband signal by another local signal. The output of the multiplier is further multiplied and then applied to a plurality of single-tuned filters which are arranged in parallel and have tuning frequencies each different from an adjacent frequency by a predetermined frequency interval. Each of the plurality of single-tuned filters generates a signal for use in carrier recovery, a frequency error signal and a correlation coefficient. Subsequently, one of the plurality of single-tuned filters is selected in a manner wherein the maximum value is detected among the correlation coefficients. The another local signal is generated using the frequency error signal of the single-tuned filter which has been selected. A modulating signal is reproduced using the recovered carrier in a conventional manner.
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公开(公告)号：DE69100673D1
公开(公告)日：1994-01-05
申请号：DE69100673
申请日：1991-05-22
Applicant: NEC CORP
Inventor： ICHIYOSHI OSAMU
Abstract: In a phase-lock loop device for phase locking a device input signal (11) representing a first complex number and having a device input phase which should be locked into a locked phase, a first complex multiplier (14) calculates a first product of the first complex number and a first conjugate complex number to produce a first complex product signal. The first conjugate complex number is represented by a first conjugate signal which is produced by delaying and processing the device input signal. A second complex multiplier (18) calculates a second product of a phase processed signal and a multiplier input signal to produce a second complex product signal. The phase processed signal is produced by filtering and processing the first complex product signal. The multiplier input signal is produced by delaying and limiting the second complex product signal. A third complex multiplier (22) calculates a third product of the first complex number and a second conjugate complex number to produce a third complex product signal. The second conjugate complex number is represented by a second conjugate signal which is produced by processing the second complex product signal. A fourth complex multiplier (24) calculates a fourth product of the second complex product signal and a filtered signal to produce a fourth complex product signal having the locked phase. The filtered signal is produced by filtering the third complex product signal.
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53.发明专利
公开(公告)号：CA2078705A1
公开(公告)日：1993-03-20
申请号：CA2078705
申请日：1992-09-21
Applicant: NEC CORP
Inventor： ICHIYOSHI OSAMU
IPC: H04L27/227 , H04L27/00 , H04L27/22 , H04L27/233
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公开(公告)号：AU623365B2
公开(公告)日：1992-05-14
申请号：AU2839989
申请日：1989-01-11
Applicant: NEC CORP
Inventor： KURAMOTO AKIO , KOSUKEGAWA KAZUO , ICHIYOSHI OSAMU , YAMANE TOSHINOBU
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公开(公告)号：CA1285338C
公开(公告)日：1991-06-25
申请号：CA578780
申请日：1988-09-29
Applicant: NEC CORP
Inventor： ICHIYOSHI OSAMU
Abstract: A satellite-based vehicle communication/position determination system constituted by N (N ? 3) geostationary satellites, a plurality of vehicle stations for performing radio-wave exchange with the satellites using a low-directivity antenna, and a base station having high-directivity antennas for independently performing radio-wave exchange with the N geostationary satellites is disclosed. The base station has a communication FDM receiver, N chirp signal receivers for receiving and pulse compressing chirp signals from a vehicle station, which are obtained via the N geostationary satellites, and a circuit for determining the position of the vehicle station based on time differences of compressed pulses from the chirp signal receivers. Each vehicle station has a communication FDM receiver, a transmitter, a chirp signal generator, and a switching control circuit for controlling to selectively output a transmitting signal or the chirp signal.
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Patent Agency Ranking
公开(公告)号：AU605720B2
公开(公告)日：1991-01-17
申请号：AU2199888
申请日：1988-09-08
Applicant: NEC CORP
Inventor： ICHIYOSHI OSAMU
Abstract: In a propagation time detecting system wherein a transmitting station transmits to a receiving station through a plurality of transmitting lines of different propagation times a transmission signal comprising a sequence of transmission data digitized by a clock signal of a clock frequency. The receiving station receives the transmission signal through the transmitting lines as different received signals and reproduces the sequence of transmission data and the clock signal as different reproduced sequence of transmission data and different reproduced clock signals from which differences are detected among the different propagation times. In order to improve accuracy of the detected differences, at least one subcarrier signal of a frequency higher than the clock frequency is also transmitted together with the transmission signal. The receiving station also reproduces the subcarrier signal as different reproduced subcarrier signals which are compared with each other to produce time differences therebetween with a reduced time order. In an application to a radar system, the transmission signal including the subcarrier signal is compared with an echo of the transmission signal from an target to produce a propagation time between the radar and the target.
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公开(公告)号：JP2003134495A
公开(公告)日：2003-05-09
申请号：JP2001330984
申请日：2001-10-29
Applicant: NEC CORP
Inventor： ICHIYOSHI OSAMU
IPC: H04B7/155 , H04B7/185 , H04H20/00 , H04H20/74 , H04L12/18 , H04L29/06 , H04L29/08 , H04N7/15 , H04N7/173 , H04N7/20 , H04N21/24 , H04N21/61 , H04H1/00
Abstract: PROBLEM TO BE SOLVED: To realize an Internet communication broadcasting network by which many users can transmit and receive broadcasting and perform a conference and a seminar through the Internet at a low cost. SOLUTION: Communication such as broadcasting, a conference and a seminar is provided to users having a satellite communication terminal capable of receiving a signal from a communication satellite 1 in a broadcasting form. A satellite communication center 3 connected to a satellite earth station 2 is provided and opens its HP on the Internet, publishing a program table 36 on the HP. When a viewer reads out the program table 36 to utilize the program table for a viewing plan, a sender immediately provides a function with which the viewer can make a reservation in empty period times of the program table 36. By using a storing and broadcasting function which stores broadcast contents sent from the sender beforehand, reads out the broadcast contents at a scheduled broadcasting time and performs satellite communication broadcasting if the reservation is established and a satellite communication line reserved by the sender by setting a communication line with the satellite communication center 3 through the Internet, etc., at a reserved time, video recording broadcasting, live broadcast, a conference, a seminar or the like are communicated.
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公开(公告)号：JPH0851410A
公开(公告)日：1996-02-20
申请号：JP18438294
申请日：1994-08-05
Applicant: NEC CORP
Inventor： ICHIYOSHI OSAMU
Abstract: PURPOSE:To provide a spread spectrum communication system and a receiver capable of establishing high speed synchronization in an (m) series having an extremely long code length. CONSTITUTION:Sampling and A/D converters 47-1, 47-2 quickly execute sampling of output base band signals from respective mixers 43-1, 43-2 and convert the sampled signals into respective binary numbers. A phase detector 49 detects the phase of an inputted received signal. A reverse diffusion circuit 50 is constituted of plural delays 51 having equal chip speed as that of a diffusion code used for the modulation of a spread spectrum modulation signal received by a receiving antenna 41, a weighting circuit 52 for multiplying weight corresponding to a spread spectrum code and an adder 53 for mutually adding an output signal from the circuit 52 and an output signal from the detector 49 and executes filtering corresponding to a characteristic polynomial 1+G(z). An LPF 54 is a digital filter for averaging an output signal from the circuit 50. A data demodulator 55 reproduces a transmission information signal.
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公开(公告)号：JPH07297783A
公开(公告)日：1995-11-10
申请号：JP10770294
申请日：1994-04-22
Applicant: NEC CORP
Inventor： ICHIYOSHI OSAMU
Abstract: PURPOSE:To provide a radio communication system which can easily introduce a telephone network to the region provided with no communication means. CONSTITUTION:A terminal station 1 is provided with an omnidirectivity antenna 1a or a directivity antenna 1b directed to a base station 2 and is a personal terminal which performs transmission and reception with the same frequency. In the base station which sets a communication line between terminal stations by the signal amplification and repeater operation, an omnidirectional transmission antennas 3 and a reception antenna 5 are arranged in such positional relations that the extent of signal coupling between them is minimum. The reception signal of the reception antenna is amplified and is supplied to the transmission antenna while using the reference signal of a specific frequency channel, which is outputted from a broadcast signal modulator 12 through the loop of an interference wave cancelling circuit 7, a buffer amplifier 8, a signal synthesizer 9, a signal distributor 10, and the interference wave cancelling circuit 7, to cancel the leakage of this reception signal to the transmission antenna.
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