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公开(公告)号：JPH03262227A
公开(公告)日：1991-11-21
申请号：JP6011090
申请日：1990-03-13
Applicant: NEC CORP
Inventor： ICHIYOSHI OSAMU
Abstract: PURPOSE:To prevent communication with an erroneous party and a secret code from being decoded with a 3rd party by executing a personal identification operation and a cryptographic operation simultaneously and managing this system such that a personal identification code and a cryptographic code used once are never used again. CONSTITUTION:Identification/cryptographic memories 32, 37 storing lots of the personal identification codes and cryptographic codes independently of the lots of personal identification codes in same addresses are provided on both communication stations, and a response requiring signal designating the address of the identification/ cryptographic memory 37 is sent from an originating station to a reception station. The reception station reads the personal identification code store in an address designated from the memory 37 and sends the code to the originating station while superimposing it onto a response signal. After confirming the personal identification code superimposed on the response signal to be correct, the originating station sends a scramble signal 12 based on cryptographic code 32-2 to send an information signal subjected to cryptographic processing The reception station uses the cryptographic code stored in the address to generate a descramble signal 23 and decodes the cryptographic reception signal.
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公开(公告)号：JPH03162159A
公开(公告)日：1991-07-12
申请号：JP30089089
申请日：1989-11-21
Applicant: NEC CORP
Inventor： ICHIYOSHI OSAMU
IPC: H04L27/20
Abstract: PURPOSE:To use a C class amplifier as a transmitting amplifier and to easily obtain high power source efficiency by modulating a carrier by a modulating signal for always setting the transition direction of a phase to the prescribed direction. CONSTITUTION:The equipment consists of a complex modulating signal generating circuit 1, a complex carrier generating circuit 2, mixers 3A, 3B, an adder 4, an amplifier 5, and an antenna 6, the complex modulating signal generating circuit 1 is constituted of a 1-bit delayer 11, a comparator 12, a real part waveform generating circuit 13, and an imaginary part waveform generating circuit 14, and the complex carrier generating circuit 2 is constituted of a carrier oscillator 21 and a pi/2 phase shifter 22. According to this constitution, the transition direction of a phase always becomes the prescribed direction, therefore, a modulation frequency characteristic becomes a single side-band. Also, amplitude of a modulated signal always becomes constant, and a linear characteristic is not required for the amplifier. In such a way, the modulating equipment which can use a C class amplifier whose frequency and power efficiency are both high, and also, whose amplitude is constant and whose power efficiency is satisfactory is obtained.
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公开(公告)号：JPH0324833A
公开(公告)日：1991-02-01
申请号：JP15925589
申请日：1989-06-21
Applicant: NEC CORP
Inventor： ICHIYOSHI OSAMU
Abstract: PURPOSE:To easily attain a privacy talking and to simplify the constitution of a system by transmitting the voice signal in a digital format. CONSTITUTION:In a transmission part, the voice signal is digitized by an A/D converter 2 and separated into frequency information and amplitude information. These pieces of information are arranged in a transmission frame in time division to form a binary data series. This data series is subjected to the enciphering processing and the error correction encoding processing and subjected to prescribed digital modulation by a modulator 11 to be transmitted. In a reception part, the data series is reproduced by digital demodulation, etc., of a demodulator 16, and frame synchronism is settled by detecting a synchronous word to reproduce frequency information and amplitude information, and the compounded audio signal is reproduced from both information. Thus, the privacy talking is easily attained and the constitution of a communication equipment is simplified without enlarging the scale.
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公开(公告)号：JPH02212929A
公开(公告)日：1990-08-24
申请号：JP3262089
申请日：1989-02-14
Applicant: NEC CORP , NIPPON ELECTRIC ENG
Inventor： ICHIYOSHI OSAMU , TANAKA SHINICHI
Abstract: PURPOSE:To realize a function of a digital voltage controlled oscillator (VCO) by fetching an input control signal by time-sharing with the use of a DSP, respectively executing arithmetic processings, and outputting processing results through a serial output port and a parallel output port. CONSTITUTION:A VCO consists of a digital signal processor (DSP) 10 operated at high speed clocks. The DSP 10 reads a binary control signal 100 supplied from the outside by an interrupting signal 120 applied from the outside, executes the arithmetic processings according to a built-in processing procedure, and the processing result is outputted from parallel output ports 11 to 18 as a parallel binary format output signal 110. Further a second control signal 100a which is different from the control signal is read, the other processing is executed according to the other built-in processing procedure, and the processing result is outputted from a serial output port 19 as a serial binary signal 200. Thus the voltage controlled oscillator which can be obtained low frequency modulating sensitivity can be obtained.
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公开(公告)号：JPH0244946A
公开(公告)日：1990-02-14
申请号：JP19672488
申请日：1988-08-05
Applicant: NEC CORP
Inventor： ICHIYOSHI OSAMU
IPC: H04L27/14 , H04L27/22 , H04L27/227
Abstract: PURPOSE:To cancel the effect of a local phase noise by inserting a delay device having the same delay as a delay in a tank circuit in a carrier recovery circuit to the demodulator. CONSTITUTION:The demodulator for M-phase (M=2 , n=1, 2,...) PSK or MSK used for digital communication consists of a carrier recovery circuit 1, a delay device 2 and a synchronization detector 3 and the carrier recovery circuit 1 is composed of an M multiplier 1, a multiplier 12, a tank circuit 13A, a limiter 14 and an (M-1) multiplier 15. Then the delay device 2 provided on the input of the synchronization detector 2 has a delay nearly equal to the delay of the tank circuit 13A tuned to a carrier frequency of a modulation signal. Thus, the effect of local phase noise is suppressed.
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Patent Agency Ranking
公开(公告)号：JPH01180103A
公开(公告)日：1989-07-18
申请号：JP413388
申请日：1988-01-11
Applicant: NEC CORP
Inventor： KURAMOTO AKIO , YAMANE TOSHINOBU , ICHIYOSHI OSAMU
Abstract: PURPOSE:To reduce the phase noise due to incomplete hardware of an antenna main body by providing a variable phase shifter shifting the phase of a signal inputted/outputted to/from input/output terminals of the antenna main body corresponding to a control signal varied periodically. CONSTITUTION:The antenna main body 1 having variable phase shifters 13, 14 is provided with a variable phase shifter 2 whose phase shift quantity is controlled by a control signal S, whose one terminal is connected to the input/ output terminal 15 and whose other terminal is used as an input/output terminal 3. Suppose that the phase shift is +5 deg., -10 deg. due to manufacture error of the phase shifter 13 and the phase shift quantity of the phase shifter 14 is ideally + or -7.84 deg., then the main body 1 applies phase modulation to a reception signal or a transmission signal by 0.36 deg. in terms of phase deviation. Thus, the change in the phase shift of the phase shifter 2 due to the signal S is set to 0.36 deg.. The phase modulation due to the main body 1 is canceled by the phase modulation by the phase shifter 2 and the antenna system without phase noise is obtained due to beam switching when viewing the terminal 3.
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公开(公告)号：JPH01176966A
公开(公告)日：1989-07-13
申请号：JP33610087
申请日：1987-12-30
Applicant: NEC CORP
Inventor： ICHIYOSHI OSAMU
Abstract: PURPOSE:To enable communication of high quality and position measurement having no vagueness at any place on the earth by arranging >=1 communication satellite each on a stationary track on the equator and >=1 day-period track slanting to the equator surface. CONSTITUTION:The day period tracks 3 and 4 which slant at, for example, +60 deg. and -60 deg. to the equator surface are set in addition to the stationary track 2 on the equator of the earth 1, and six communication satellites S1-S6, Y1-Y6, and X1-X6 are arranged on those tracks in proper correlation. Then at least three communication satellites can easily be tracked and acquired within a 90 deg. visual field at any high-elevation position on the earth including an equator area and a polar region. Therefore, not only the communication, but also the position measurement are performed without any vagueness. At this time, those three satellites and a ground state are not on the same plane, so there is not any problem of vagueness.
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公开(公告)号：JPH01117451A
公开(公告)日：1989-05-10
申请号：JP27493987
申请日：1987-10-30
Applicant: NEC CORP
Inventor： ICHIYOSHI OSAMU
Abstract: PURPOSE:To surely and quickly attain the establishment of clock synchronization by recovering a clock independently of the recovery of a carrier. CONSTITUTION:A latter half delay detection phase and its deviation from pi/4 are obtained by the cooperation of components such as a 1st complex number multiplier 11a, a 1st absolute value device 13a, a 1st adder 12a and a 3rd absolute value device 13c. Moreover, a 1st half delay detection phase and its deviation from pi/4 are obtained by the cooperation of components such as a 2nd complex number multiplier 11b, a 2nd absolute value device 13b, a 2nd adder 12b and a 4th absolute value device 13d. Then a difference between the deviation of a latter half delay detection phase from pi/4 and the 1st half delay detection phase from pi/4 is obtained by a 3rd adder 14 and it is used as a control signal for a digital VCO to apply phase control of a recovered clock (double clock) of the digital VCO 7. Thus, the clock synchronization is established.
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公开(公告)号：JPS6488273A
公开(公告)日：1989-04-03
申请号：JP24628587
申请日：1987-09-30
Applicant: NEC CORP
Inventor： ICHIYOSHI OSAMU
Abstract: PURPOSE:To enable the execution of rapid and highly precise measurement in addition to bidirectional communications without increasing a circuit scale, by using a chirp signal based on SCPC (single-channel per carrier) - FDMA (frequency division multiplexing connection). CONSTITUTION:Two or more geostationary satellites are added to a moving- body satellite communication system of an SCPC-FDMA method. A base station is constituted by a frequency divider 1, a data demodulator 2 as a receiving means, a reception control circuit 3, chirp signal receiving circuits 4a-4c and a time difference detecting circuit 5. A moving body is constituted by a data demodulator 21 as a receiving means, a reception frame sync circuit 22, a reception control circuit 23, a chirp signal generating circuit 24, etc. In the moving body, the circuit 24 generates a chirp signal for conducting frequency sweep of all working bandwidths for a certain time and at a certain sweep speed. In the base station, on the other hand, the circuits 4a-4c conduct a pulse compression processing for the chirp signal, and the circuit 5 detects a time difference between compressed pulses and forms a position-measurement signal for calculating the position of the moving body.
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公开(公告)号：JPS6471329A
公开(公告)日：1989-03-16
申请号：JP22808887
申请日：1987-09-11
Applicant: NEC CORP
Inventor： ICHIYOSHI OSAMU
Abstract: PURPOSE:To form a voice and data line with high quality by allowing a transponder of a communication satellite to apply channel separation to a received frequency division split multiplex signal and sending it as a time division multiplex signal, allowing plural mobile stations to select a channel signal to apply demodulation and reproduction. CONSTITUTION:Plural mobile stations 103 on the earth modulate voice and data respectively and send the result to a communication satellite 100 as a frequency division multiplex signal via a corresponding beam. A transponder 101 of the satellite 100 uses a branching circuit so as to separate the frequency division signal and applies the time division multiplex to the output of a base band matrix connected to a beam SB to be sent and sends the result. A mobile station 103 selects a channel signal to be received from the sent time division multiplex signal to demodulate and reproduce the signal. Thus, voice and data lines with high quality are offered to lots of mobile stations in a wide district covered by plural beams in this way.
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