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41. 发明专利

JPH07170225A RADIO COMMUNICATION SYSTEM 失效
公开(公告)号：JPH07170225A
公开(公告)日：1995-07-04
申请号：JP31520393
申请日：1993-12-15
申请人： FUJITSU LTD
发明人： NAKAZAWA ISAO
IPC分类号： H04B7/08 , H04B7/10 , H04B7/26 , H04B17/00 , H04B17/309 , H04W24/00
摘要： PURPOSE:To instantaneously measure the propagation characteristics of a line at all times while operating the line concerning the radio receiver of a base station to receive signals transmitted from plural mobile stations in the radio communication system, especially, in the case of mobile object communication. CONSTITUTION:A frequency converter 3 simultaneously receives the respective signals transmitted from plural mobile stations 1 and 2 and respectively frequency-converts them into IF band signals. The respective IF band signals separated just for the difference of the frequency between the respective transmitted signals from the plural mobile stations 1 and 2 are outputted from the frequency converter 3. A complex Fourier transforming means 4 performs batch complex Fourier transformation to these IF band signals and outputs a frequency spectrum to an analyzing means 5. At the analyzing means 5, based on the transmitted frequency spectrum, the propagation characteristics of the respective received waves are simultaneously analyzed for each burst constituting each received wave. Corresponding to this analyzed result, the received wave presenting the satisfactory propagation characteristics can be received.

42. 发明专利

JPH0434844B2 失效
公开(公告)号：JPH0434844B2
公开(公告)日：1992-06-09
申请号：JP22905483
申请日：1983-12-06
申请人： FUJITSU LTD
发明人： NAKAZAWA ISAO , KYONO HIDEKI
IPC分类号： H03F3/30 , H03F3/20 , H03F3/213

43. 发明专利

JPS6233778B2 失效
公开(公告)号：JPS6233778B2
公开(公告)日：1987-07-22
申请号：JP15460481
申请日：1981-09-29
申请人： FUJITSU LTD
发明人： NAKAZAWA ISAO , AKUTSU MASAHARU
IPC分类号： G01R19/25 , H03G3/20 , H03G3/30 , H04B17/00

44. 发明专利

JPS62101134A RADIO COMMUNICATION SYSTEM 失效
公开(公告)号：JPS62101134A
公开(公告)日：1987-05-11
申请号：JP24067085
申请日：1985-10-29
申请人： FUJITSU LTD
发明人： NAKAZAWA ISAO , HACHITSUKA HIROYUKI , DOI YOSHIKAZU
IPC分类号： H04J3/00 , H04B7/04 , H04L1/06 , H04L1/22 , H04L12/28
摘要： PURPOSE:To ensure excellent communication quality by connecting plural antennas radially to a node transmitter/receiver, applying communication with a terminal transmitter/receiver by a burst signal and applying reception processing a burst signal having a maximum reception level among plural burst signals of the same content. CONSTITUTION:Plural antennas are arranged scatteringly and connected radially, the node transmitter/receiver 1 uses each antenna 2 in time division and sends the burst signal of the same content so as not to overlap the signal timewise, the terminal transmitter/receiver 3 receives the burst signals from each antenna 2 while the signals are arranged on a time base, and the burst signals from the terminal transmitter/receiver 3 are received by each antenna 2 at the same time, and the node transmitter/receiver 1 applies reception control to the reception burst signal corresponding to the antenna so as to arrange them on the time base. The node transmitter/receiver 1 and the terminal transmitter/receiver 3 detect the quality of the reception burst signal and process the burst signal of the best quality of the reception signal as the reception signal.

45. 发明专利

JPS6257326A TWO-WAY TRANSMISSION LINE SUPERVISORY SYSTEM 失效
公开(公告)号：JPS6257326A
公开(公告)日：1987-03-13
申请号：JP19639285
申请日：1985-09-05
申请人： FUJITSU LTD
发明人： NAKAZAWA ISAO
IPC分类号： H04B17/00 , H04B3/46 , H04B3/48
摘要： PURPOSE:To supervise directly the sound transmission state of the own station while supervising a line by detecting a level of a sound signal superimposed on a received picture signal and returning the signal while superimposing the detected level signal onto the picture signal sent to a reverse line. CONSTITUTION:The sound input at the left end station is sent and received to a right end station via a transmission line 8 after being modulated by a modulator 1. The right end station uses a hybrid circuit 12 to branch the reception signal and applies it to demodulators 14, 15, an output of the demodulator 14 is outputted as a substantial sound signal and the output of he demodulator 15 is used for the display of the output level. A part of the output of the demodulator 14 is detected by a sound level detector 16, becomes a sound level signal, which is modulated by a modulator 17 and superimposed on a signal sent from the right end station to the left end signal via the hybrid circuit 12 and the result is sent to a transmission line 18. The sound level signal is extracted via a hybrid circuit 3 and a demodulator 5 in the left end station.

46. 发明专利

JPS61174839A DISCRIMINATION CODE TRANSMISSION SYSTEM 失效
公开(公告)号：JPS61174839A
公开(公告)日：1986-08-06
申请号：JP1590385
申请日：1985-01-30
申请人： FUJITSU LTD
发明人： NAKAZAWA ISAO
IPC分类号： H04J1/00 , H04J1/08
摘要： PURPOSE:To prevent a malreception by multiplexing a modulated wave, where a subcarrier is modulated digitally with a discrimination code generated by a discrimination code generator with a frequency division to a main signal consisting of sound signal or the like and transmitting them. CONSTITUTION:A discrimination code generator 10 generates a discrimination code assigned to its own station by an ROM or the like. This discrimination code modulates the frequency of the subcarrier by a digital modulator 11, and this modulated wave is multiplexed with the main signal by a multiplexing circuit 12, and they are arranged on the frequency base. Since the subcarrier waves modulated by the discrimination code and the main signal are multiplexed in frequency division, lines are easily discriminated from one another.

47. 发明专利

JPS6025354A RADIO COMMUNICATION SYSTEM 失效
公开(公告)号：JPS6025354A
公开(公告)日：1985-02-08
申请号：JP13370983
申请日：1983-07-22
申请人： FUJITSU LTD
发明人： NAKAZAWA ISAO , TSUKAGOSHI KENJIYU
IPC分类号： H04L27/32
摘要： PURPOSE:To prevent the deterioration in the ratio of carrier to the noise of a carrier by applying ASK modulation to the carrier subjected to PSK modulation or FSK modulation with a sub-modulation signal in synchronizing with a main modulation signal and converted into the combination of 1, 0 and 0, 1 codes. CONSTITUTION:The digitized main modulation signal (1) is fed to a PSK modulator PSK-MOD, the sub-modulation signal (4) is fed to a signal processing S and a clock signal (2) is applied to the both. Further, the output of a carrier oscillator in the PSK modulator PSK-MOD is subjected to PSK modulation by the main modulation signal and the result is outputted from a terminal (3). The carrier from the terminal (3) is subjected to the ASK modulation further by a signal (5) processed at the signal processing section S by an ASK modulator ASK- MOD, the signal is subjected to frequency conversion and amplification at a transmission section TX and transmitted to an opposite station from an output terminal OUT. The reception station demodulates the signal and extracts the signal.

48. 发明专利

JPS604609B2 失效
公开(公告)号：JPS604609B2
公开(公告)日：1985-02-05
申请号：JP17759281
申请日：1981-11-05
申请人： FUJITSU LTD
发明人： NAKAZAWA ISAO , UMEDA ATSUSHI
IPC分类号： H03C3/08 , H03C3/22

49. 发明专利

JPS605617A HIGH FREQUENCY SWITCHING CIRCUIT 失效
公开(公告)号：JPS605617A
公开(公告)日：1985-01-12
申请号：JP11332983
申请日：1983-06-23
申请人： FUJITSU LTD , NIPPON TELEGRAPH & TELEPHONE
发明人： NAKAZAWA ISAO , SAITOU TOSHIYUKI , KURITA OSAMU , OGAWA HIROTSUGU
IPC分类号： H03G3/30 , H03G3/20 , H04L27/04 , H04L27/20
摘要： PURPOSE:To prevent a spread of a spectrum accompanying the intermittency of a high frequency signal and control the level of the high frequency signal by controlling the gain of a variable gain amplifier and controlling the level of the output high frequency signal. CONSTITUTION:The high frequency signal is switched with the composite signal H of a reference signal and the signal of the component of the difference between a reference waveform and the signal obtained by amplifying the output signal envelope detected by a signal detecting circuit DT through the variable gain amplifier with an optional gain, performing feedback control. A waveform shaping circuit WS performs waveform shaping so that the spread of the spectrum of the switched high frequency signal appearing at an output terminal is reduced sufficiently, so the spread of the spectrum of the high frequency signal made into a burst. Further, a high frequency switching circuit controls the gain of the VGA with a level control signal to control the level of the switched high frequency signal.

50. 发明专利

JPS60132A DATA TRANSMISSION CIRCUIT 失效
公开(公告)号：JPS60132A
公开(公告)日：1985-01-05
申请号：JP10716283
申请日：1983-06-15
申请人： FUJITSU LTD
发明人： NAKAZAWA ISAO
IPC分类号： H04J3/00 , H04J3/16
摘要： PURPOSE:To transmit data with high efficiency by synthesizing selectively the data and clock signals with a time division mutiple access signal to transmit then, and reproducing the signal at the reception side to divide it into a data signal and a time division multiple access switch control signal for outputting. CONSTITUTION:The data signal, the time division multiple access TDMA signal and the clock signal are supplied to terminals 1, 2 and 3 respectively of the transmission part. The data and clock signals extracted selectively at the output sides of gate circuits G1 and G2 and added together by a synthesizing circuit A. Then the data signal is correctly inserted to the part where no clock signal is contained. While the signal received from a terminal 5 of the reception part and supplied to signal reproducing circuits F1 and F2 and the signal shifted by half are reproduced and applied to a data reproducing circuit G3 and a TDMA switch control signal generating circuit G4. Then the data signal and the TDMA switch control signal are extracted out of terminals 7 and 8 respectively.

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