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1. 发明专利

JPH1127330A DIGITAL SIGNAL MODULATION METHOD AND DEMODULATION METHOD 失效
公开(公告)号：JPH1127330A
公开(公告)日：1999-01-29
申请号：JP18151797
申请日：1997-07-07
申请人： NIPPON TELEGRAPH & TELEPHONE , SUZUKI HIROSHI , KYODA JUNICHI
发明人： FUKAWA KAZUHIKO , SUZUKI HIROSHI , KYODA JUNICHI
IPC分类号： H04L27/18 , H04B1/10 , H04B7/005 , H04B7/26
摘要： PROBLEM TO BE SOLVED: To allow a maximum likelihood series estimate means to obtain a transfer coefficient of a transmission channel without divergence by making an autocorrelation matrix regular at all times. SOLUTION: At a transmitter side, a specific code that takes alternately a phase O or a phase π/4 (phase 0 or a phase π/8) for each symbol is multiplied with a digital modulation series [b(i)] such as a BPSK (QPSK) (32) and transmits a multiplied output (34). Then at a receiver side, a timing is recovered from a base band signal (51), a demodulation means 36 is operated at the timing, a maximum likelihood series estimate means estimates an object Sm(i) from a received base band signal x(i), generates an inverse matrix Rm (i) of its autocorrelation matrix, obtains a cross correlation between the signal x(i) and the object Sm(i) (41), and a carrier phase estimate means 42 obtains a product between the cross correlation Vm(i) and the matrix Rm (i) to obtain a transmission channel transfer coefficient Wm(i).

2. 发明专利

JPH10209997A PACKET MOBILE COMMUNICATION METHOD AND BASE STATION RECEIVER THEREFOR 失效
公开(公告)号：JPH10209997A
公开(公告)日：1998-08-07
申请号：JP921397
申请日：1997-01-22
申请人： NIPPON TELEGRAPH & TELEPHONE , SUZUKI HIROSHI
发明人： FUKAWA KAZUHIKO , SUZUKI HIROSHI
IPC分类号： H04J3/16 , H04B7/26 , H04W74/08 , H04Q7/38
摘要： PROBLEM TO BE SOLVED: To improve the degradation of packet abandonment and error rate characteristics due to packet collisions in a slotted aloha system. SOLUTION: The training signals 27 of the code sequence having excellent orthogonality mutually different for respective packets are disposed to the head of the packet from a mobile equipment. In this base station receiver, reception packet signals are quasi-synchronously detected, the correlation of base band signals and the training signals for each mobile equipment is detected in a multi-user training signal detector 23, the packet from which mobile equipment is present is judged and respective packet signals are separated and demodulated in a multi-user demodulator 34 for each judged mobile equipment.

3. 发明专利

JPH11261445A ADAPTIVE TYPE SPREAD SPECTRUM RECEIVER 失效
公开(公告)号：JPH11261445A
公开(公告)日：1999-09-24
申请号：JP5972998
申请日：1998-03-11
申请人： NIPPON TELEGRAPH & TELEPHONE , SUZUKI HIROSHI
发明人： FUKAWA KAZUHIKO , SUZUKI HIROSHI
IPC分类号： H03H17/02 , H04B1/707 , H04B1/7097
摘要： PROBLEM TO BE SOLVED: To allow a receiver to operate satisfactorily even when the timing cycle of a desired wave is incomplete or when there is a multi path element of a small delay time difference. SOLUTION: ADS-CDMA-receiver signal sampled at a constant interval of time is supplied to plural matching filter 22-1 and 22-2 and plural quadrature filters 23-1 and 23-2. The matching filters 22-1 and 22-2 determine a filter coefficient regarding the matching filter 22-1 so that the matching filter 22-2 matches the spreading code of a desired wave distorted only for a quarter tip cycle(TC). Also, the spreading code of the quadrature filters 23-1 and 23-2 is made orthogonal with the spreading code of the desired wave delayed by 0 and Tc/4. Outputs of these filters are multiplied to by a weight coefficient, added by an adder and the weight coefficient is set so that their average power becomes minimum under a restricting condition.

4. 发明专利

DE69432447T2 未知
公开(公告)号：DE69432447T2
公开(公告)日：2003-12-24
申请号：DE69432447
申请日：1994-01-18
申请人： NIPPON TELEGRAPH & TELEPHONE
发明人： YOSHINO HITOSHI , FUKAWA KAZUHIKO , SUZUKI HIROSHI
IPC分类号： H04B1/12 , H04L25/02 , H04L25/03 , H04B1/10 , H04B7/005

5. 发明专利

DE69432100T2 未知
公开(公告)号：DE69432100T2
公开(公告)日：2003-09-25
申请号：DE69432100
申请日：1994-11-04
申请人： NIPPON TELEGRAPH & TELEPHONE
发明人： SUZUKI HIROSHI
IPC分类号： H04B3/23 , H04L25/03 , H04B7/005 , H04B3/06 , H04L27/01

6. 发明专利

CA2208842C BOOSTER SYSTEM 未知
公开(公告)号：CA2208842C
公开(公告)日：2001-01-16
申请号：CA2208842
申请日：1996-10-28
申请人： NIPPON TELEGRAPH & TELEPHONE
发明人： ITO KAZUHITO , NAKADA MANABU , SUZUKI HIROSHI , EBINE YOSHIO
IPC分类号： H04B7/155 , H04B7/005 , H04B7/015 , H04Q7/08
摘要： 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.

7. 发明专利

DE69215944D1 未知
公开(公告)号：DE69215944D1
公开(公告)日：1997-01-30
申请号：DE69215944
申请日：1992-04-08
申请人： NIPPON TELEGRAPH & TELEPHONE
发明人： FUKAWA KAZUHIKO , SUZUKI HIROSHI
IPC分类号： H04L25/03 , H04L25/30
摘要： In an apparatus for equalization in an impulse response of mobile transmission which varies fast in mobile radio communication, a signal generating circuit (12-3, 12-5) outputs a signal sequence undergoing transition at a predetermined period and corresponding to each state transition and a signal sequence corresponding to the path of each state transition. An adaptive filter (12-1) receives the signal sequence corresponding to each state transition and outputs an estimated signal for each state transition. The apparatus also includes state estimating circuits for performing state estimation by using the square of an estimation error obtained by subtracting each estimated signal from a sampled signal, and a control circuit (12-4) for controlling the tap coefficient of the adaptive filter (12-1) by using the RLS algorithm in order to minimize the square of the estimation error.

8. 发明专利

CA2046399C EQUALIZER FOR RADIO RECEIVE SIGNAL 未知
公开(公告)号：CA2046399C
公开(公告)日：1995-02-14
申请号：CA2046399
申请日：1991-07-05
申请人： NIPPON TELEGRAPH & TELEPHONE
发明人： UEDA TAKASHI , SUZUKI HIROSHI , YOSHINO HITOSHI
IPC分类号： H04L25/03 , H04B1/16 , H04B7/005
摘要： In a transversal type equalizer having a series connected delay elements, multipliers coupled with each output of each delay element and an adder for adding outputs of said multipliers to provide an equalized output signal for equalizing time division radio receive signal for every burst in mobile communication, a receive memory (11) for storing receive signal, a transversal type equalization process circuit (77a) coupled with output of said memory (11), and an output memory (100) for storing equalized output signal are provided. In training tap coefficients of a transversal filter, a tap or a delay element is precluded when an absolute value of a tap coefficient is less than a predetermined value, so that calculation amount for updating tap coefficients is decreased and tracking characteristics are improved; a multiplier (15) is inserted between an output of said receive memory (11) and an input of said equalization process circuit (77a) so that a signal which is subject to equalization is phase-shifted beforehand so that frequency offset between transmit frequency in a transmitter and local frequency in a receiver is compensated. The phase adjustment by said multiplier (15) depends upon residual phase error at output of said equalization process circuit (77a); an output memory (100) is used as a training signal to initialize the tap coefficients of said equalization process circuit (77a) during a burst when equalized output signal has error larger than a predetermined value.

9. 发明专利

DE69434518T2 未知
公开(公告)号：DE69434518T2
公开(公告)日：2006-06-22
申请号：DE69434518
申请日：1994-12-14
申请人： NIPPON TELEGRAPH & TELEPHONE
发明人： FUKAWA KAZUHIKO , YOSHINO HITOSHI , SUZUKI HIROSHI
IPC分类号： H04L25/03 , H04B7/005 , H04L27/01 , H04L27/233
摘要： Base-band signals obtained by asynchronously detecting received signals are sampled and the signals, are written in a buffer memory (11) as series of base-band signals samples. A most likelihood sequence estimating sec, tion (15) generates a desired symbol sequence corresponding to the samples read from the memory (11) and supplies the symbol sequence to a transversal filter (18) having characteristics esti. mated from the impulse response of the transmission line at the timings of the samples. A phase error detecting section (23) successively detects the phase errors between estimated received signals obtained and corresponding base-band signal samples. An offset correcting signal generating section (22) calculates an estimated offset angular frequency DELTA omega e from the phase errors, generates an offset correcting signal having an angular frequency in the reverse direction of rotation, whose absolute value is equal to that of the estimated offset angular frequency DELTA omega e, and supplies the offset correcting signal to a multiplier (21) for correction. The multiplier (21) corrects the offset angular frequency so as to cancel the angular frequency offset by multiplying the samples by the offset correcting signal. A subtractor (14) finds the difference between the corrected samples and estimated signals received from the transversal filter as estimated errors. The estimating section (15) finds the most likelihood information from the estimated errors and discriminates signals by using a most likelihood sequence estimating algorithm based on the most likelihood information.

10. 发明专利

DE69635606D1 未知
公开(公告)号：DE69635606D1
公开(公告)日：2006-01-26
申请号：DE69635606
申请日：1996-10-28
申请人： NIPPON TELEGRAPH & TELEPHONE
发明人： ITO KAZUHITO , SUZUKI HIROSHI , NAKADA MANABU , EBINE YOSHIO
IPC分类号： H04B1/40 , H04B7/14 , H04B7/155
摘要： 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.

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